Co-reporter:Jing Bai, Qing He, Zixing Shi, Ming Tian, Hongjie Xu, Xiaodong Ma, Jie Yin
Polymer 2017 Volume 116(Volume 116) pp:
Publication Date(Web):5 May 2017
DOI:10.1016/j.polymer.2017.03.080
•C60 could be co-assembled into PB phase of the furan modified SBS via Diels-Alder (DA) reaction at the molecular level.•The morphology of SBS could be effectively tailored by addition of C60 and even small amount of C60 could lead to great change in the morphologies.•The hybrids based on SBS and C60 possessed the self-healing and remolding abilities via retro-Diels-Alder (rDA) reaction.In this article, C60 could be co-assembled into PB phase of the furan modified poly(styrene-b-butadiene-b-styrene) (SBS) via Diels-Alder (DA) reaction at the molecular level. The morphology of SBS could be effectively tailored by the incorporation of C60 and even small amount of C60 could lead to great change in the morphologies of SBS. Three types of morphologies of SBS could be observed as the content of C60 was increased from 0.1 to 2 wt%, which included honeycomb like, worm-like bi-continuous phase and their intermediate transition state. In the meantime, it was unexpectedly found that C60 could be used as effective crosslinking agents to build the network toward the furan modified SBS via DA reaction. Therefore, its solvent resistance, elastic resilience and tensile strength were greatly improved for the chemical crosslinking. Besides, due to the thermal reversible character for DA reaction, the hybrids based on SBS and C60 possessed the self-healing and remolding abilities via retro-Diels-Alder (rDA) reaction. All in all, C60 could provide the multiple functions toward the modification of SBS via DA reaction.Download high-res image (366KB)Download full-size image
Co-reporter:Changxu Zhang;Zhiyong Liu;Xinhui Zhang;Hongjie Xu;Xiaodong Ma;Jie Yin;Ming Tian
Polymer Chemistry (2010-Present) 2017 vol. 8(Issue 35) pp:5367-5373
Publication Date(Web):2017/09/12
DOI:10.1039/C7PY01105A
Hydrogels have promising applications in biomaterials and other fields. Here, to extend our previous work, we designed a novel class of PEA-P-A-polyacrylamide (PAAm) hydrogels that contain two cooperative H-bonding interactions: PEO/amide groups and diol/carbonyl groups via a versatile platform (PEA). The strong H-bonding between PEA-P-A and PAAm endows the PEA-P-A-PAAm hydrogel with excellent performance (tensile strength is up to 1.15 MPa and elongation at break is up to 1277%). The reversible association and disassociation of the H-bonding impart the PEA-P-A-PAAm hydrogels with pH response and reshaping ability. PEA-P-A-20%-PAAm hydrogels can change the diameter from 4 cm to 2 cm, accompanied by their color change from transparent to white in a pH < 1 solution within 20 minutes. The sample of the PEA-P-A-PAAm hydrogel also can be reshaped into a programmed shape by using the dynamic H-bonding. PEA-P-A-PAAm hydrogels with excellent mechanical properties, fast pH response and reshaping ability could accelerate the practical applications of the hydrogels in many fields.
Co-reporter:Changxu Zhang;Zhiyong Liu;Tiantian Li;Hongjie Xu;Xiaodong Ma;Jie Yin;Ming Tian
Polymer Chemistry (2010-Present) 2017 vol. 8(Issue 11) pp:1824-1832
Publication Date(Web):2017/03/14
DOI:10.1039/C7PY00053G
Conventional hydrogels cross-linked by small molecular cross-linkers usually exhibit poor mechanical properties, limiting the application of hydrogels to a certain degree. Here, inspired by the fabrication technologies of elastomers, we firstly fabricate a macromolecular hydrogel pre-polymer (MHP) via thermal polymerization and then crosslink the MHP at a macromolecular level by UV irradiation. In this novel technology, polyetheramine (PEA) plays an important role in the fabrication of crosslinked hydrogels. In the thermal polymerization stage, N–CH3 units in PEA acted as co-initiators and grafting agents to form an MHP. Under the UV irradiation, benzophenone (BP) moieties in PEA could be excited as photo-cross-linkers. More importantly, the tensile stress of PEA5%-PAAm hydrogel could be effectively tailored from 180 kPa to 500 kPa by controlling the crosslinking degree under different irradiation times. Through this important characteristic, we could also effectively build a hydrogel with a complex three dimensional (3D) geometry, which is not easily obtained by conventional polymerization methods.
Co-reporter:Hui Li, Jing Bai, Zixing Shi, Jie Yin
Polymer 2016 Volume 85() pp:106-113
Publication Date(Web):24 February 2016
DOI:10.1016/j.polymer.2016.01.050
•The materials were synthesized based on schiff base reaction which was dynamic.•The materials can be remolded, self-healing and degradable.•The structure of the polymer can be designed according to various needs.In this paper, we have synthesized crosslinked polymers that can be remolded, self-healing and degradable, which provide us more freedom on how to treat the crosslinked polymer after they are damaged or out of use. This type of crosslinked polymer is fabricated by dynamic bonding linkage based on Schiff base reaction between commercial available terephthalaldehyde (A2) and diamine (B2) using tri(2-aminoethyl)amine (B3) as crosslinking agent. The network could be easily tailored by changing the ratio of B3 to B2 (R) and increasing R could lead to increasing the crosslinking degree. As a result, the sample could be gradually changed from weak to strong materials with increasing R based on the data of mechanical properties. Most of important, this type of crosslinked polymers could show good self-healing and remolded behavior. The crosslinked sample could also be remolded at 120 °C under hot pressure without the compromise of its mechanical properties and the temperature for self-healing could be controlled from room temperature (∼20 °C) to 55 °C based on the different R. In the meantime, they could also be completely degraded into small molecules under the acidic condition for 2 days. All these characters could provide an ideal solution to the crosslinked polymers which is totally friendly to the environment.
Co-reporter:Jing Bai, Zixing Shi, Jie Yin
Polymer 2016 Volume 98() pp:229-236
Publication Date(Web):19 August 2016
DOI:10.1016/j.polymer.2016.06.038
•The pristine carbon nanotubes were used without modification and function in advance.•The dynamical crosslinked network was formed between pristine carbon nanotubes and macromolecular diene.•The mechanical properties of this series of hybrid could be tailored.In this paper, the pristine carbon nanotubes (CNTs) could directly act as dienophile and furan modified polybutadiene elastomer could be used as macromolecular diene to take part in the formation of inorganic-organic network via Diels-Alder reaction, which was quite a convenient and original method. The success of the crosslinking reaction was assessed by swelling measurements and the chemical structure and morphologies of carbon nanotubes in the hybrid were confirmed via Raman, FT-IR, SEM and TEM. Via this simple method, the final hybrid materials could be only swollen in the toluene at room temperature, which indicated that the pristine CNTs could really act as inorganic crosslinking agents toward the furan modified polybutadiene elastomer. The mechanical properties of this series of hybrid could be tailored by the content of CNTs and furan grafting ratio. For example, with increasing the content of CNTs up to 20%, the modulus could be increased from 3.58 to 13.20 MPa for PB-30Fu-yCNTs series. Due to the dynamic nature of DA reaction, the CNTs could be successfully recycled and the crosslinked hybrid films could also be remolded by solution casting method via retra-DA reaction. In this way, the service life for this kind of crosslinked hybrids could be prolonged in a sustainable way, which is quite different from the conventional method to produce carbon nanotubes-polymer hybrids.
Co-reporter:Min Lian, Jinchen Fan, Zixing Shi, Sai Zhang, Hong Li, Jie Yin
Carbon 2015 Volume 89() pp:279-289
Publication Date(Web):August 2015
DOI:10.1016/j.carbon.2015.03.045
In this study, a high-performance graphene-based nacre was prepared using gelatin as a bioadhesive with the aid of the bending cycle-induced “mechanical annealed” effect. By this method, this type of graphene-based nacre is endowed with high strength, toughness, and electrical conductive properties, which is very different from other study where only one or two of three properties were improved. The maximum ultimate tensile strength can reach as high as ∼630.4 MPa when the optimal amount of gelatin was 30 wt%. Meanwhile, it has a high electrical conductivity of ∼42,624 S/m. Most notably, the periodic bending-induced “mechanical annealing” could further increase the ultimate tensile strength tremendously. After 100 cycles of periodic bending, the ultimate strength reached ∼902.1 MPa, with a high electrical conductivity of ∼44,780 S/m.
Co-reporter:Jing Bai, Hui Li, Zixing Shi, Ming Tian and Jie Yin
RSC Advances 2015 vol. 5(Issue 56) pp:45376-45383
Publication Date(Web):19 May 2015
DOI:10.1039/C5RA08719H
Poly(styrene-block-butadiene-block-styrene) (SBS) is a typical example of thermal plastic elastomers (TPE). People usually encounter a well-known paradox for SBS, where improving its poor solvent resistance and low mechanical properties usually means it suffers from losing its thermal plastic remolding ability, one of most important characters for TPE. In this paper, we propose a novel solution for this problem. SBS was first modified with furan via a thiol–ene reaction and then reacted with bismaleimide to form thermally dynamic reversible crosslinking linkages for SBS via a Diels–Alder reaction. As a result, the dynamic crosslinked SBS could only swell in the toluene with improved solvent resistance at ambient temperature. The mechanical properties showed great improvement. As an example, the maximum tensile strength was obtained at 14.96 MPa, increased by almost 8 times in comparison with the pure SBS and the tensile strain was still kept above 800%. More importantly, the crosslinked SBS could still be thermal plastic remolded due to the de-crosslinking reaction via a retro-DA reaction at higher temperature and the mechanical properties still remained almost the same even after 3 generations of remolding. The merits of this modified SBS originate from its dynamic crosslinking network to improve its mechanical properties and solvent resistance without sacrificing its thermal plastic remolding ability.
Co-reporter:Jing Bai, Hui Li, Zixing Shi, and Jie Yin
Macromolecules 2015 Volume 48(Issue 11) pp:3539-3546
Publication Date(Web):May 15, 2015
DOI:10.1021/acs.macromol.5b00389
We reported a novel method of producing the cross-linked polybutadiene elastomer which could be thermally recycled like the plastic materials without the sacrifice of functional utility. The commercial polybutadiene was first attached with furan via thiol–ene reaction, and the cross-linked network was then built via Diels–Alder click reaction between the bismaleimide and attached furan groups from polybutadiene. The obtained polymer had good solvent resistance from ambient temperature to 100 °C. The mechanical properties of modified polybutadiene could be tailored by the amount of attached furan and the ratio of furan to bismaleimide. Furthermore, the dynamic cross-linked polybutadiene had good thermally remolded and self-healing behaviors. By this method, the dynamic cross-linked polybutadiene could be recycled to use in a sustainable way. Concerning all the raw materials were available in large quantities without tedious and multistep synthetic routes, this work demonstrated the high performance recycling solution to the commercial cross-linked polybutadiene, which might be applied in industry in relatively short time.
Co-reporter:Hong Li, Jinchen Fan, Zixing Shi, Min Lian, Ming Tian, Jie Yin
Polymer 2015 60() pp: 96-106
Publication Date(Web):
DOI:10.1016/j.polymer.2014.12.069
Co-reporter:Min Lian, Jinchen Fan, Zixing Shi, Hong Li, Jie Yin
Polymer 2014 Volume 55(Issue 10) pp:2578-2587
Publication Date(Web):13 May 2014
DOI:10.1016/j.polymer.2014.03.059
Multiwalled carbon nanotubes (MWCNTs) have been widely used as reinforcement fillers in past decades. However, the reinforcement effect has been greatly hindered by the limited available interface area (AIA) with polymer matrices for polymer composites. Successively, the method of oxidative unzipping MWCNTs into graphene nanoribbons (GNRs) was demonstrated to be the effective way for addressing the inherent drawback of MWCNTs. However, the GNRs are easy to agglomerate in polymer matrix even at relatively low loading amount. In this paper, we found that the functionalization of GNRs with Kevlar® can significantly improve the dispersion state of GNRs in polymer matrix. Consequently, Kevlar®-functionalized graphene nanoribbons (KGNRs) were successfully prepared through non-covalent functionalization of π–π stacking interaction between the aromatic area of Kevlar® and the graphitic surface of GNRs. As-prepared KGNRs were characterized by FT-IR, TGA, XRD and TEM measurements. Poly(vinyl chloride) (PVC) and poly(methyl methacrylate) (PMMA) were selected as model polymers to investigate the reinforcement effect of KGNRs. The KGNRs could be well dispersed in PVC and PMMA matrices at relatively high loading level. Meantime, the ultimate tensile strengths and Young's modulus of KGNRs/PVC and KGNRs/PMMA composite films were significantly improved. Based on the observations above, KGNRs hold great promise in many potential applications in the future.
Co-reporter:Jing Bai, Zixing Shi, Jie Yin, and Ming Tian
Macromolecules 2014 Volume 47(Issue 9) pp:2964-2973
Publication Date(Web):April 16, 2014
DOI:10.1021/ma5004024
Benzoxazine-functionalized poly(styrene-b-butadiene-b-styrene) (SBS) has been successfully synthesized via the thiol–ene click reaction. Unlike the typical method for fabrication of blends of SBS and thermosetting resins, the benzoxazine could be directly attached on to the chains of PB domains of this triblock copolymer without any prechemical modification for SBS via the incorporation of thiol functionalized benzoxazine (PTMP-BZ). AFM characterization shows that both thiol–ene and subsequent benzoxazine ring-opening reactions have a profound influence on the final morphologies of SBS, which undergoes great change from the cylinders for the pure SBS to different types of lamella structure for the SBS with different contents of the benzoxazines and the results obtained from AFM indicate that the interaction between PB and PS domains is strengthened after two reaction steps and this is responsible for the substantial improvement on the mechanical properties of material including tensile strength and storage modulus. In the meantime, the resilence of SBS is also improved significantly by the incorporation of benzoxazine and the modified SBS blends could recover its original shape without residual elongation after the tests of cyclic tensile stress–strain.
Co-reporter:Jinchen Fan, Zixing Shi, Min Lian, Hong Li and Jie Yin
Journal of Materials Chemistry A 2013 vol. 1(Issue 25) pp:7433-7443
Publication Date(Web):27 Mar 2013
DOI:10.1039/C3TA10639J
In this paper, a novel graphene oxide (GO)/sodium alginate (SA)/polyacrylamide (PAM) ternary nanocomposite hydrogel with excellent mechanical performance has been fabricated through free-radical polymerization of acrylamide (AAm) and SA in the presence of GO in an aqueous system followed with ionically crosslinking of calcium ions. As-prepared GO/SA/PAM (weight ratio SA:AAm = 1:2) ternary nanocomposite hydrogel with 5 wt% of GO displays a compressive stress as high as 1.543 MPa at the compressive deformation of 70%. The tensile strength and modulus of the hydrogel achieved ∼201.7 and ∼30.8 kPa, respectively. In the meantime, the ternary nanocomposite hydrogels can recover a large proportion of elongation at breakage and exhibits good elasticity. Additionally, the GO/SA/PAM ternary nanocomposite hydrogel exhibited good adsorption properties for water-soluble dyes. After introducing GO, the dye adsorption capacities of the hydrogel were significantly improved.
Co-reporter:Jinchen Fan, Zixing Shi, Ming Tian and Jie Yin
RSC Advances 2013 vol. 3(Issue 39) pp:17664-17667
Publication Date(Web):26 Jul 2013
DOI:10.1039/C3RA42515K
A novel mechanically strong, electrically conductive nanocomposite paper based on reduced graphene oxide nanosheets and aramid nanofibers was prepared by vacuum-assisted filtration followed by reduction.
Co-reporter:Jing Bai
Journal of Applied Polymer Science 2013 Volume 128( Issue 3) pp:1785-1791
Publication Date(Web):
DOI:10.1002/app.38286
Abstract
A novel kind of benzoxazine precursors made of 4-dihydroxybenzophenone (DHBP), formaldehyde and N, N′-diethylethylenediamine was developed. The striking feature of this class of precursors is that it can be acted as an effective photo initiator for polymerization of acrylate monomers. In addition, this kind of precursors could be directly dispersed in water and its aqueous solution exhibited very sharp response to temperature, with a well-defined cloud point. The structure of this precursor has been confirmed by Proton Nuclear Magnetic Resonance Spectroscopy (1H-NMR) and Fourier Transform Infrared spectroscopy (FTIR) and its curing behaviors are investigated by Differential Scanning Calorimetry (DSC). The photopolymerization of acylate monomers, initiated by this precursor, was studied through photo-DSC. The results show that this precursor is dramatically more efficient than benzophenone (BP), in which the polymerization rate is almost four times as high as that of the BP system. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Co-reporter:Jinchen Fan, Jialiang Wang, Zixing Shi, Shan Yu, Jie Yin
Materials Chemistry and Physics 2013 Volume 141(2–3) pp:861-868
Publication Date(Web):16 September 2013
DOI:10.1016/j.matchemphys.2013.06.015
•Surface functionalization of carbon nanotubes with Kevlar nanofibers.•Functionalized carbon nanotubes can be well-dispersed in solvents.•The nanocomposites exhibit a remarkable improvement of mechanical properties.Multiwalled carbon nanotubes (MWNTs) have been widely used as nanofillers for polymer reinforcement due to their excellent mechanical properties. However, for MWNTs-based polymer composites, the rigid surface, poor dispersibility and weak interaction of MWNTs still limited the potential and further application in mechanical reinforcement. In this paper, we report a facile method for functionalization of MWNTs with Kevlar nanofibers. Kevlar nanofiber-functionalized multiwalled carbon nanotubes (KNCNTs) were successful obtained by the simple process of solution mixing followed with sonication. The as-prepared KNCNTs can be well dispersed in water and dimethylsulfoxide (DMSO) solvents. In the next, poly(vinyl alcohol) (PVA) and poly(methyl methacrylate) (PMMA) were chosen as model polymer for investigating the reinforcement effect of KNCNTs. The results of tensile tests demonstrated that the ultimate tensile strengths and Young's modulus of KNCNTs/PVA and KNCNTs/PMMA nanocomposite films were significantly improved. The KNCNTs have an advantage over the pristine MWNTs for polymer reinforcement.
Co-reporter:Jing Bai, Zixing Shi, Jie Yin
Polymer 2013 Volume 54(Issue 10) pp:2498-2505
Publication Date(Web):26 April 2013
DOI:10.1016/j.polymer.2013.03.031
In this paper, a series of benzophenone-based polybenzoxazine (PBD) was synthesized through the formation of oxazine rings, and the structures of the obtained polymers were confirmed by FTIR, 1H NMR and UV–visible analysis. As the existence of benzophenone units in the main chain, PBD could initiate photopolymerization of various monomers. The photo-initiative behavior of PBD was tested by differential scanning photocalorimetry, which shows the high photopolymerization efficiency. Meanwhile, PBD could be used as film substrates for initiating photopolymerization of the monomers and change the surface performance without additional initiator. Through this method, the surface properties of PBD film could be tailored conveniently. The surface wettability modifications through the surface photo-polymerization of styrene (St) and N-isopropyl acrylamide (NiPAM) were carried out for example, and the surface properties were investigated by water contact angle measurements (WCA), X-ray photoelectron spectroscopy (XPS) and Atom Force Microscopy (AFM) and the results showed that the surface properties PBD film could be well designed by selecting different kind of monomer through photopolymerization to realize an easy-tuned surface with desired wettability required.
Co-reporter:Jinchen Fan, Zixing Shi, Jialiang Wang, Jie Yin
Polymer 2013 Volume 54(Issue 15) pp:3921-3930
Publication Date(Web):8 July 2013
DOI:10.1016/j.polymer.2013.05.057
Chemically-modified gum arabic with glycidyl methacrylate was used for liquid-phase direct exfoliation of graphite. Using this technique, glycidyl methacrylate-modified gum arabic-functionalized graphene flakes can be easily obtained by centrifugal separation after sonication. It was demonstrated by transmission electron microscopy, atomic force microscopy, Fourier transform infrared spectroscopy, X-ray diffraction, Raman spectroscopy and thermogravimetric analysis. The functionalized graphene flakes, coupled with vinyl groups coming from the glycidyl methacrylate-modified gum arabic, were introduced into a poly (acrylic acid) hydrogel to improve its mechanical property. Compared to poly (acrylic acid) hydrogel, the compressive strength and elastic modulus of the graphene/poly (acrylic acid) composite hydrogel with 5 wt% of functionalized graphene flakes reach ∼49.2 and ∼66.9 kPa, increased by ∼846.1% and ∼243.7%, respectively.
Co-reporter:Yu Ge, Jialiang Wang, Zixing Shi and Jie Yin
Journal of Materials Chemistry A 2012 vol. 22(Issue 34) pp:17619-17624
Publication Date(Web):10 Jul 2012
DOI:10.1039/C2JM33173J
Two dimensional nanomaterials are of great significance in a wide range of applications due to their high surface area and novel properties. Here we offer a simple and large-scale method to prepare graphene and its inorganic analogues (MoS2, WS2 and boron nitride) by the sonication of their bulk materials in an aqueous solution of gelatin. The concentrations of the obtained stable dispersions were up to 0.6, 0.8, 0.9 and 1.4 mg mL−1 for graphene, MoS2, WS2 and boron nitride, respectively. Transmission electron microscopy strongly suggests that the materials have been exfoliated into few- or mono-layer thin sheets. Specifically, graphene and MoS2 dispersion have been directly employed to fabricate gelatin–graphene composites. Scanning electron microscope images show that graphene flakes were homogeneously dispersed in the composites. The tensile test results show that the mechanical properties of gelatin films have been remarkably improved by graphene rather than MoS2.
Co-reporter:Jinchen Fan, Zixing Shi, Lu Zhang, Jialiang Wang and Jie Yin
Nanoscale 2012 vol. 4(Issue 22) pp:7046-7055
Publication Date(Web):09 Oct 2012
DOI:10.1039/C2NR31907A
Aramid macroscale fibers, also called Kevlar fibers, exhibit extremely high mechanical performance. Previous studies have demonstrated that bulk aramid macroscale fibers can be effectively split into aramid nanofibers (ANFs) by dissolution in dimethylsulfoxide (DMSO) in the presence of potassium hydroxide (KOH). In this paper, we first introduced the ANFs into the structure of graphene nanosheets through non-covalent functionalization through π–π stacking interactions. Aramid nanofiber-functionalized graphene sheets (ANFGS) were successfully obtained by adding the graphene oxide (GO)/DMSO dispersion into the ANFs/DMSO solution followed by reduction with hydrazine hydrate. The ANFGS, with ANFs absorbed on the surface of the graphene nanosheets, can be easily exfoliated and dispersed in N-methyl-2-pyrrolidone (NMP). Through a combination of these two ultra-strong materials, ANFs and graphene nanosheets (GS), the resultant ANFGS can act as novel nanofillers for polymer reinforcement. We used the ANFGS as an additive for reinforcing the mechanical properties of poly(methyl methacrylate) (PMMA). With a loading of 0.7 wt% of the ANFGS, the tensile strength and Young's modulus of the ANFGS/PMMA composite film approached 63.2 MPa and 3.42 GPa, which are increases of ∼84.5% and ∼70.6%, respectively. The thermal stabilities of ANFGS/PMMA composite films were improved by the addition of ANFGS. Additionally, the transparencies of the ANFGS/PMMA composite films have a degree of UV-shielding due to the ultraviolet light absorption of the ANFs in the ANFGS.
Co-reporter:Jialiang Wang, Zixing Shi, Yu Ge, Yan Wang, Jinchen Fan and Jie Yin
Journal of Materials Chemistry A 2012 vol. 22(Issue 34) pp:17663-17670
Publication Date(Web):10 Jul 2012
DOI:10.1039/C2JM32124F
Multiwalled carbon nanotubes (MWNTs) have been widely used as mechanical reinforcement agents during the past decades. However, the complete achievement of mechanical enhancement has been greatly impeded by their limited available interfacial area (AIA) and weak adhesion force with the polymer matrix. In this paper, we use unzipped MWNTs (uCNTs) as a precursor to fabricate poly(methyl methacrylate) (PMMA) functionalized uCNTs (uCNTs-P) via in situ free radical polymerization. Fourier transform infrared (FTIR), X-ray powder diffraction (XRD), X-ray photoelectron spectra (XPS), Raman, and thermogravimetric analysis (TGA) are applied to characterize the structure of resultant uCNTs-P. The mechanical testing of composite films indicated that uCNTs-P were more effective than uCNTs and functionalized MWNTs in improving the tensile strength and Young's modulus. This excellent reinforcement is attributed to uCNTs-P's highly available interfacial area and the strong interlocking force with the polymer matrix. This study will guide the design of functionalized uCNTs and the preparation of high-performance polymer composites.
Co-reporter:Jinchen Fan, Zixing Shi, Yu Ge, Jialiang Wang, Yan Wang and Jie Yin
Journal of Materials Chemistry A 2012 vol. 22(Issue 27) pp:13764-13772
Publication Date(Web):18 Apr 2012
DOI:10.1039/C2JM31437A
Gum arabic (GA), a natural polymer, is extensively used in food, drug, confectionery and soft drinks processing. In this paper, we present a green and facile approach for preparing graphene–Ag nanohybrids assisted by GA. In brief, GA functionalized graphene sheets (GA-G) were prepared by directly exfoliating graphite flakes in gum arabic (GA) aqueous solution with sonication. The yield of graphene exfoliation was systemically studied by varying the initial graphite concentration, GA concentration and sonication time. Furthermore, the GA functionalized graphene sheets–Ag nanoparticle hybrids (Ag/GA-G) were fabricated by adding AgNO3 aqueous solution into the GA-G water dispersion. The silver ions were directly reduced and immobilized on the surface of the GA-G nanosheets by GA. The Ag/GA-G hybrid materials can be used as suitable substrates of SERS for the detection of 4-aminothiophenol (4-ATP) at a detectable level of a concentration of 10−6 M in aqueous environments.
Co-reporter:Jialiang Wang, Zixing Shi, Jinchen Fan, Yu Ge, Jie Yin and Guoxin Hu
Journal of Materials Chemistry A 2012 vol. 22(Issue 42) pp:22459-22466
Publication Date(Web):06 Sep 2012
DOI:10.1039/C2JM35024F
Three-dimensional (3D) structures of graphene have attracted extensive interest for their practical applications, such as supercapacitors and catalyst supports. Self-assembly is a typical technique to fabricate macroscopic graphene materials integrated with various superior properties. However, an efficient and environmentally-friendly strategy is still needed. In this paper, we report a green and mild method for the synthesis of 3D architectures of graphene. This proposed method is based on the chemical reduction of graphene oxide (GO) with the aid of a range of natural phenolic acids and in situ self-assembly of graphene sheets via π–π interactions. The obtained monolithic graphene exhibits low density, super hydrophobicity, high porosity, excellent mechanical strength and electrical conductivity. These multifunctional products can be used as adsorbents for removal of oils, organic solvents and dyes from contaminated water, as well as electrode materials for supercapacitors.
Co-reporter:Jinchen Fan, Zixing Shi, Ming Tian, Jialiang Wang, and Jie Yin
ACS Applied Materials & Interfaces 2012 Volume 4(Issue 11) pp:5956
Publication Date(Web):November 2, 2012
DOI:10.1021/am301623t
Multiwalled carbon nanotubes (MWNTs) have been widely used as nanofillers for polymer reinforcement. However, it has been restricted by the limited available interface area of MWNTs in the polymer matrices. Oxidation unzipping of MWNTs is an effective way to solve this problem. The unzipped multiwalled carbon nanotube oxides (UMCNOs) exhibit excellent enhancement effect with low weight fractions, but agglomeration of UMCNOs at a relatively higher loading still hampered the mechanical reinforcement of polymer composites. In this paper, we interestingly found that the dispersion of UMCNOs in polymer matrices can be significantly improved with the combination of pristine MWNTs. The hybrids of MWNTs and UMCNOs (U/Ms) can be easily obtained by adding the pristine MWNTs into the UMCNOs aqueous dispersion, followed by sonication. With a π-stacking interaction, the UMCNOs were attached onto the outwalls of MWNTs. The morphologies and structure of the U/Ms were characterized by several measurements. The mechanical testing of the resultant poly(vinyl alcohol) (PVA)-based composites demonstrated that the U/Ms can be used as ideal reinforcing fillers. Compared to PVA, the yield strength and Young’s modulus of U/M–PVA composites with a loading of 0.7 wt % of the U/Ms approached ∼145.8 MPa and 6.9 GPa, respectively, which are increases of ∼107.4% and ∼122.5%, respectively. The results of tensile tests demonstrated that the reinforcement effect of U/Ms is superior to the individual UMCNOs and MWNTs, because of the synergistic interaction of UMCNOs and MWNTs.Keywords: multiwalled carbon nanotube; reinforcement; unzipped multiwalled carbon nanotube oxide;
Co-reporter:Ru Zhang;ZhiXing Shi;Yang Liu ;Jie Yin
Journal of Applied Polymer Science 2012 Volume 125( Issue 4) pp:3191-3199
Publication Date(Web):
DOI:10.1002/app.36497
Abstract
Poly[2,2′-(p-oxydiphenylene)-5,5′-bibenzimidazole] (OPBI) was polymerized in poly(phosphoric acid) (PPA) with the presence of the pristine nanodiamonds (NDs) (0.2–5 wt %) to fabricate NDs-g-OPBI/OPBI nanocomposites via Friedel–Crafts (F-C) reaction. The OPBI chains were successfully attached to the NDs through F-C reaction between carboxylic acid from OPBI and NDs, which was proved by nuclear magnetic resonance, X-ray photoelectron, and X-ray diffraction. NDs-g-OPBI/OPBI nanocomposites show more homogeneous dispersion than the physical blending containing pristine NDs and OPBI matrix, as showed through scanning electronic microscopy images. The mechanical properties, including Young's modulus, yield strength, and tensile strength are all improved by the introduction of NDs (<1 wt %) without loss of ductility, which overcomes the brittleness brought by the addition of inorganic reinforced agent in traditional composites. Dynamic mechanical analysis results showed that the modulus of the ND-g-OPBI/OPBI nanocomposites was significantly higher than OPBI matrix, and the NDs-g-OPBI/OPBI nanocomposites displayed more pronounced improvement than the physical blending, which could be ascribed to the homogeneous dispersion of NDs particles and the covalent bonding between NDs and OPBI via F-C reaction. Thermogravimetric analysis indicated that all the OPBI nanocomposites containing NDs displayed the improved thermal stability. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Co-reporter:Jialiang Wang, Zixing Shi, Yu Ge, Yan Wang, Jinchen Fan, Jie Yin
Materials Chemistry and Physics 2012 Volume 136(Issue 1) pp:43-50
Publication Date(Web):14 September 2012
DOI:10.1016/j.matchemphys.2012.06.017
Graphene (GP)-based polymer nanocomposites have attracted considerable scientific attention due to its pronounced improvement in mechanical, thermal and electrical properties compared with pure polymers. However, the preparation of well-dispersed and high-quality GP reinforced polymer composites remains a challenge. In this paper, a simple and facile approach for preparation of poly(methyl methacrylate) (PMMA) functionalized GP (GPMMA) via in situ free radical polymerization is reported. Fourier transform infrared (FTIR), X-ray photoelectron spectra (XPS), Raman, transmission electron microscope (TEM) and thermogravimetric analysis (TGA) are used to confirm the successful grafting of PMMA chains onto the GP sheets. Composite films are prepared by incorporating different amounts of GPMMA into the PMMA matrix through solution-casting method. Compared with pure PMMA, PMMA/GPMMA composites show simultaneously improved Young's modulus, tensile stress, elongation at break and thermal stability by addition of only 0.5 wt% GPMMA. The excellent reinforcement is attributed to good dispersion of high-quality GPMMA and strong interfacial adhesion between GPMMA and PMMA matrix as evidenced by scanning electron microscope (SEM) images of the fracture surfaces. Consequently, this simple protocol has great potential in the preparation of various high-performance polymer composites.Graphical abstractHighlights► Functionalization of solvent exfoliated graphene by in situ polymerization. ► A simple and scalable method for preparing high-quality graphene. ► Functionalized graphene can be well-dispersed and have a strong interfacial adhesion with the polymer matrix. ► The nanocomposites exhibit a remarkable improvement of thermal and mechanical properties.
Co-reporter:Jinchen Fan, Zixing Shi, Yu Ge, Yan Wang, Jialiang Wang, Jie Yin
Polymer 2012 Volume 53(Issue 2) pp:657-664
Publication Date(Web):24 January 2012
DOI:10.1016/j.polymer.2011.11.060
Co-reporter:Yan Wang, Zixing Shi, Jianhua Fang, Hongjie Xu, Xiaodong Ma and Jie Yin
Journal of Materials Chemistry A 2011 vol. 21(Issue 2) pp:505-512
Publication Date(Web):26 Oct 2010
DOI:10.1039/C0JM02376K
The emerging field of graphene(GP)-based polymer nanocomposites has continued to be the focus of considerable interest in recent years because of the unparalleled improvement shown in mechanical, thermal, and electrical properties compared to the neat polymer. However, these improvements largely depend on the synthesis of well-exfoliated and high-quality GP. In this paper, we report a facile method for the production of GP sheets through the liquid-phase exfoliation of graphite in methanesulfonic acid (MSA). Raman, X-ray photoelectron and infrared spectroscopies reveal that the obtained GP has a low-defect density with a low degree of oxidation. Transmission electron microscopy and atomic force microscopy further confirm that the resulting GP is in the well-exfoliated state. Using this GP/MSA solution as a reaction solvent medium, polymer nanocomposites are prepared by in situpolymerization of poly [2,2′-(p-oxydiphenylene)-5,5′-bibenzimidazole] (OPBI). Compared to pure OPBI, the resulting OPBI/GP nanocomposites show simultaneously improved Young's modulus, tensile stress, toughness, storage modulus and thermal stability with the addition of extremely small amounts of GP. The high levels of reinforcement are attributed to the good dispersion and effective stress transfer between polymer and GP as evidenced by SEM images of the fracture surfaces, and the excellent intrinsic properties of the high-quality GP. All these features make this simple procedure a potential route for the fabrication of low-cost and high-performance polymer nanocomposites.
Co-reporter:Yan Wang, Zixing Shi and Jie Yin
Journal of Materials Chemistry A 2011 vol. 21(Issue 30) pp:11371-11377
Publication Date(Web):27 Jun 2011
DOI:10.1039/C1JM10342C
Boron nitride
nanosheets (BNNSs) are two dimensional crystals composed of boron and nitrogen atoms covalently bonded in a hexagonal manner with exceptional physiochemical properties. However, the researches on BNNS are rather limited due to the lack of an efficient method to prepare BNNS. In this study, we report a facile and efficient method for the fabrication of BNNS through liquid-phase exfoliation of hexagonal boron nitride particles (h-BNs) in methanesulfonic acid. The resultant BNNS can be readily disperse in a number of organic solvents, such as N-methyl-2-pyrrolidone. Transmission electron microscopy and atomic force microscopy confirms that the obtained BNNSs are mainly single or few-layered with a thickness less than 3 nm. X-Ray photoelectron and infrared spectroscopy reveal that almost no compositional change occurred in BNNS during the superacid-assistant exfoliation process. The BNNS holds great promise in a number of important applications as demonstrated in this study of poly [2,2′-(p-oxydiphenylene)-5,5′-bibenzimidazole] (OPBI)/BNNS composites. The OPBI/BNNS composites showed superior mechanical and thermal properties as compared to neat OPBI and h-BN reinforced ones.
Co-reporter:Yan Wang, ZiXing Shi, and Jie Yin
ACS Applied Materials & Interfaces 2011 Volume 3(Issue 4) pp:1127
Publication Date(Web):March 25, 2011
DOI:10.1021/am1012613
The chemical reduction of graphene oxide (GO) typically involves highly toxic reducing agents that are harmful to human health and environment, and complicated surface modification is often needed to avoid aggregation of the reduced GO during reduction process. In this paper, a green and facile strategy is reported for the fabrication of soluble reduced GO. The proposed method is based on the reduction of exfoliated GO in green tea solution by making use of the reducing capability and the aromatic rings of tea polyphenol (TP) that contained in tea solution. The measurements of the resultant graphene confirm the efficient removal of the oxygen-containing groups in GO. The strong interactions between the reduced graphene and the aromatic TPs guarantee the good dispersion of the reduced graphene in both aqueous and a variety of organic solvents. These features endow this green approach with great potential in constructing of various graphene-based materials, especially for high-performance biorelated materials as demonstrated in this study of chitosan/graphene composites.Keywords: composites; functionalization; graphene oxide; green reduction; tea polyphenol
Co-reporter:Yan Wang, Zixing Shi, Jianhua Fang, Hongjie Xu, Jie Yin
Carbon 2011 Volume 49(Issue 4) pp:1199-1207
Publication Date(Web):April 2011
DOI:10.1016/j.carbon.2010.11.036
Homogenous organic dispersion of graphene oxide (GO) sheets was prepared by a solvent-exchange method. This method enabled the simultaneous achievement of full exfoliation and high concentration of GO in several organic solvents such as dimethyl sulfoxide, which would facilitate the fabrication of individual graphene reinforced polymer composites through a solution-based process. To this end, poly [2,2′-(p-oxydiphenylene)-5,5′-bibenzimidazole] (OPBI)/GO composites were fabricated. X-ray diffraction characterization showed that the GO sheets were individually incorporated into the OPBI matrix. Scanning electron microscope images that taken of the fracture surface of the composites revealed that the GO sheets were spontaneous aligned parallel to the surface of the composite films as the content of GO exceeded 0.3 wt.%. The incorporation of GO also showed profound effects on the macroscopic properties of OPBI. Compared to pure OPBI, the composites showed a 17% increase in Young’s modulus, 33% increase in tensile strength and 88% improvement in toughness by the addition of only 0.3 wt.% of GO. Moreover, although the thermal stability of GO is far inferior to OPBI, it is found the thermal stability of OPBI is still improved by the addition of GO.
Co-reporter:Tian Tang
Journal of Applied Polymer Science 2011 Volume 120( Issue 3) pp:1758-1766
Publication Date(Web):
DOI:10.1002/app.33370
Abstract
Multiwalled carbon nanotubes (MWNTs)-reinforced poly(hydroxyaminoether) (PHAE) was fabricated via one pot graft-from method. The modification of MWNTs and in situ polymerization of PHAE were combined in one reaction pot without interruption for the purification of modified carbon nanotubes. Fourier transform infrared, scanning electron microscopy, transmission electron microscopy, and Raman spectra clearly indicated that PHAE was successfully attached to the surface of MWNTs via esterification reaction between epoxy and carboxylic acid from MWNTs. Tensile tests showed that the tensile strength and modulus of PHAE/MWNTs composites were improved compared with that of pristine PHAE. Moreover, the reinforcing effect of one pot graft-from method was found to be better than that of graft-to method. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Co-reporter:Tian Tang, Zixing Shi, Jie Yin
Materials Chemistry and Physics 2011 Volume 129(1–2) pp:356-364
Publication Date(Web):15 September 2011
DOI:10.1016/j.matchemphys.2011.04.016
Poly [2,2′-(p-oxydiphenylene)-5,5′-benzimidazole] (OPBI) functionalized MWNTs (MWNTs-g-OPBI) were firstly prepared via Friedel–Crafts acylation reaction in PPMA as medium. The overall evidences based on the data from FT-IR, Raman, TGA as well as TEM implicated that the OPBI chains were successfully linked to the surface of MWNTs. The obtained MWNTs-g-OPBI were then used as reinforced fillers in 100% acidified poly(hydroxyaminoether) (A-PHAE) to prepare A-PHAE/MWNTs-g-OPBI composites. The acid–base interaction between the OPBI chains attached on MWNTs and A-PHAE played a crucial role in good dispersion of MWNTs-g-OPBI in the polymer matrix and effective reinforcement of A-PHAE.Highlights► Friedel-Crafts acylation reaction was used in the functionalization of MWNTs. ► Acid-base interaction was utilized in the reinforcement of polymer with MWNTs. ► Mechanical and thermal properties of the composites were all improved.
Co-reporter:Yan Wang, ZiXing Shi, Jie Yin
Polymer 2011 Volume 52(Issue 16) pp:3661-3670
Publication Date(Web):20 July 2011
DOI:10.1016/j.polymer.2011.06.012
Kevlar oligomer functionalized graphene (FGS) was prepared by simple grafting of amino-terminated Kevlar oligomer on graphene oxide (GO) followed by reducing with hydrazine hydrate. The incorporation of FGS shows pronounced effect on the host polymers. High-level reinforcement of both PMMA and PI is observed with low content of FGS (≤0.2 wt %), in this lower loading range, the tensile modulus and strength of composites increase almost linearly as a function of the adding amount of FGS. But no further improvement is obtained as the content of FGS further increased (>0.2 wt %). The mechanism under the reinforcement effect against the FGS loadings is discussed based on the morphological characterizations of the composites. The thermal properties of the composites were also investigated. The glass transition temperature and thermal stability of PMMA were dramatically increased even with the addition of only a small amount of FGS.Kevlar oligomer functionalized graphenes were used as reinforcing agents for fabrication of polymer composites. The composites showed greatly enhanced properties as compared to neat polymer at an extremely small fraction of fillers.
Co-reporter:Yang Liu, Zixing Shi, Hongjie Xu, Jianhua Fang, Xiaodong Ma and Jie Yin
Macromolecules 2010 Volume 43(Issue 16) pp:6731-6738
Publication Date(Web):July 20, 2010
DOI:10.1021/ma1011792
The organic−inorganic nanocomposites involving OPBI (poly[2,2′-(p-oxidiphenylene)-5,5′-bibenzimidazole]) and polyhedral oligomeric silsesquioxane (POSS) were prepared via in situ polymerization of 4,4′-dicarboxydiphenyl ether (DCDPE) and 3,3′-diaminobenzidine (DABz) in the presence of the POSS where the organic group on silsesquioxane cage is phenyl. NMR, XPS, and XRD characterization of POSS-g-OPBI, purified from the POSS-g-OPBI/OPBI hybrid, revealed that the OPBI chains were successfully attached to the phenyl group of the POSS through Friedel−Crafts (F−C) reaction. The homogeneous dispersion of POSS cages in the polymer matrix was evidenced by SEM. The DMA results showed that the moduli of the POSS-g-OPBI/OPBI nanocomposites were significantly higher than OPBI matrix, indicating the nano-reinforcement effect of POSS cages. Thermogravimetric analysis indicated that the thermal stability of the polymer matrix was not sacrificed but improved by introducing a small amount of POSS since POSS showed lower thermal stability than OPBI. More importantly, the mechanical properties, including tensile and yield strength, Young’s modulus, and toughness, were obviously simultaneously increased by introducing POSS into the nanocomposite, which is quite differently from the traditional nanocomposites, where the ductility and toughness of polymer were usually reduced substantially upon the incorporation of inorganic reinforced agent.
Co-reporter:Yan Wang ; ZiXing Shi ;Jie Yin
The Journal of Physical Chemistry C 2010 Volume 114(Issue 46) pp:19621-19628
Publication Date(Web):November 3, 2010
DOI:10.1021/jp107151e
Multiwalled carbon nanotubes (MWNTs) have been widely used as mechanical reinforcement agents in the past few years. However, the enhancement of mechanical properties of composites has been greatly hampered by its limited available interface area in composites. Toward solving this intrinsic limitation of MWNTs, in this paper, we report the use of unzipped MWNTs (uCNTs) as nanofillers for reinforcement of polymer composites for the first time. The uCNTs were produced by an oxidative unzipping process, involving the lengthwise cutting and opening the walls of MWNTs, and yielded separated ribbonlike graphene layers, thus increasing the surface area of MWNTs. With different amounts of oxidant (KMnO4), uCNTs with different unzipping degrees were obtained. For the surface functional groups that were generated during oxidation treatment, the morphologies and structures of uCNTs with different unzipping degrees were well characterized by several measurements. The mechanical testing of the resultant poly(vinyl alcohol)-based composites confirmed that the uCNTs were more effective than pristine MWNTs in terms of reinforcing polymers in strength and modulus, and the uCNTs oxidized by 400 wt % KMnO4 showed the highest reinforcement effect. The reinforcement effect is correlated with the structure changes of CNTs. This study may provide an important guideline and alternative way to design and fabricate low-cost and high-performance polymer−CNT composites.
Co-reporter:Xiayun Huang;Hongcui Cao
Journal of Materials Science: Materials in Medicine 2010 Volume 21( Issue 6) pp:1829-1835
Publication Date(Web):2010 June
DOI:10.1007/s10856-010-4059-8
Amino-bearing polymers, coated with apatite or similar minerals, have attracted significant attention for their potential in medical applications. In this study, an amino-terminated hyperbranched polybenzimidazole (HBPBI) membrane was used as a substrate for apatite growth. The membrane was soaked in solutions of CaCl2, Na2HPO4 and SBF to yield an apatite coating. The structure and morphology of the layers were characterized by FTIR-ATR, XRD and FESEM. The results indicate that the high densities of amino, imide and imidazole groups on the amino-terminated HBPBI membrane provide active sites for the growth of apatite.
Co-reporter:Huanzhen Shao, Zixing Shi, Jianhua Fang, Jie Yin
Polymer 2009 50(25) pp: 5987-5995
Publication Date(Web):
DOI:10.1016/j.polymer.2009.10.044
Co-reporter:Zhaori Yu, Zixing Shi, Hongjie Xu, Xiaodong Ma, Ming Tian, Jie Yin
Carbon (April 2017) Volume 114() pp:
Publication Date(Web):April 2017
DOI:10.1016/j.carbon.2016.12.049
In this paper, we successfully prepared low-defect exfoliated graphene-based soft nacre-like composite film with superb elasticity and electrical conductivities, which is quite different from the conventional graphene oxide based film. Herein, we demonstrate a large-scale exfoliation process of graphite by incorporation of Myrtan Condensed Tannins (MCT), a natural polyphenol product extracted from bark of Arbutus. MCT could successfully produce large quantities of exfoliated graphene suspension (2.33 mg mL−1) with very few defects (ID/IG ∼ 0.27) in water, where more than 68% of these flakes are monolayer. Furthermore, via vacuum-assisted layer-by-layer self-assembled method, the soft and elastic exfoliated graphene-based nacre-like composite film was prepared using epoxy natural rubber (ENR) latex as crosslinking agent. Flexibility and stability of this graphene-based electrical conductive film are greatly enhanced at the same time. The composite films could be stretched by 20% of its initial length with 54 wt % of ENR in it and it could also be directly used as a conductive wire for an LED lamp with a conductivity of 157 S m−1. Most importantly, most of the raw materials used in this work are low cost natural products which is environmental-friendly and also suitable for production in large quantities.
Co-reporter:Yan Wang, Zixing Shi and Jie Yin
Journal of Materials Chemistry A 2011 - vol. 21(Issue 30) pp:NaN11377-11377
Publication Date(Web):2011/06/27
DOI:10.1039/C1JM10342C
Boron nitride
nanosheets (BNNSs) are two dimensional crystals composed of boron and nitrogen atoms covalently bonded in a hexagonal manner with exceptional physiochemical properties. However, the researches on BNNS are rather limited due to the lack of an efficient method to prepare BNNS. In this study, we report a facile and efficient method for the fabrication of BNNS through liquid-phase exfoliation of hexagonal boron nitride particles (h-BNs) in methanesulfonic acid. The resultant BNNS can be readily disperse in a number of organic solvents, such as N-methyl-2-pyrrolidone. Transmission electron microscopy and atomic force microscopy confirms that the obtained BNNSs are mainly single or few-layered with a thickness less than 3 nm. X-Ray photoelectron and infrared spectroscopy reveal that almost no compositional change occurred in BNNS during the superacid-assistant exfoliation process. The BNNS holds great promise in a number of important applications as demonstrated in this study of poly [2,2′-(p-oxydiphenylene)-5,5′-bibenzimidazole] (OPBI)/BNNS composites. The OPBI/BNNS composites showed superior mechanical and thermal properties as compared to neat OPBI and h-BN reinforced ones.
Co-reporter:Jinchen Fan, Zixing Shi, Min Lian, Hong Li and Jie Yin
Journal of Materials Chemistry A 2013 - vol. 1(Issue 25) pp:NaN7443-7443
Publication Date(Web):2013/03/27
DOI:10.1039/C3TA10639J
In this paper, a novel graphene oxide (GO)/sodium alginate (SA)/polyacrylamide (PAM) ternary nanocomposite hydrogel with excellent mechanical performance has been fabricated through free-radical polymerization of acrylamide (AAm) and SA in the presence of GO in an aqueous system followed with ionically crosslinking of calcium ions. As-prepared GO/SA/PAM (weight ratio SA:AAm = 1:2) ternary nanocomposite hydrogel with 5 wt% of GO displays a compressive stress as high as 1.543 MPa at the compressive deformation of 70%. The tensile strength and modulus of the hydrogel achieved ∼201.7 and ∼30.8 kPa, respectively. In the meantime, the ternary nanocomposite hydrogels can recover a large proportion of elongation at breakage and exhibits good elasticity. Additionally, the GO/SA/PAM ternary nanocomposite hydrogel exhibited good adsorption properties for water-soluble dyes. After introducing GO, the dye adsorption capacities of the hydrogel were significantly improved.
Co-reporter:Jialiang Wang, Zixing Shi, Yu Ge, Yan Wang, Jinchen Fan and Jie Yin
Journal of Materials Chemistry A 2012 - vol. 22(Issue 34) pp:NaN17670-17670
Publication Date(Web):2012/07/10
DOI:10.1039/C2JM32124F
Multiwalled carbon nanotubes (MWNTs) have been widely used as mechanical reinforcement agents during the past decades. However, the complete achievement of mechanical enhancement has been greatly impeded by their limited available interfacial area (AIA) and weak adhesion force with the polymer matrix. In this paper, we use unzipped MWNTs (uCNTs) as a precursor to fabricate poly(methyl methacrylate) (PMMA) functionalized uCNTs (uCNTs-P) via in situ free radical polymerization. Fourier transform infrared (FTIR), X-ray powder diffraction (XRD), X-ray photoelectron spectra (XPS), Raman, and thermogravimetric analysis (TGA) are applied to characterize the structure of resultant uCNTs-P. The mechanical testing of composite films indicated that uCNTs-P were more effective than uCNTs and functionalized MWNTs in improving the tensile strength and Young's modulus. This excellent reinforcement is attributed to uCNTs-P's highly available interfacial area and the strong interlocking force with the polymer matrix. This study will guide the design of functionalized uCNTs and the preparation of high-performance polymer composites.
Co-reporter:Yu Ge, Jialiang Wang, Zixing Shi and Jie Yin
Journal of Materials Chemistry A 2012 - vol. 22(Issue 34) pp:NaN17624-17624
Publication Date(Web):2012/07/10
DOI:10.1039/C2JM33173J
Two dimensional nanomaterials are of great significance in a wide range of applications due to their high surface area and novel properties. Here we offer a simple and large-scale method to prepare graphene and its inorganic analogues (MoS2, WS2 and boron nitride) by the sonication of their bulk materials in an aqueous solution of gelatin. The concentrations of the obtained stable dispersions were up to 0.6, 0.8, 0.9 and 1.4 mg mL−1 for graphene, MoS2, WS2 and boron nitride, respectively. Transmission electron microscopy strongly suggests that the materials have been exfoliated into few- or mono-layer thin sheets. Specifically, graphene and MoS2 dispersion have been directly employed to fabricate gelatin–graphene composites. Scanning electron microscope images show that graphene flakes were homogeneously dispersed in the composites. The tensile test results show that the mechanical properties of gelatin films have been remarkably improved by graphene rather than MoS2.
Co-reporter:Yan Wang, Zixing Shi, Jianhua Fang, Hongjie Xu, Xiaodong Ma and Jie Yin
Journal of Materials Chemistry A 2011 - vol. 21(Issue 2) pp:NaN512-512
Publication Date(Web):2010/10/26
DOI:10.1039/C0JM02376K
The emerging field of graphene(GP)-based polymer nanocomposites has continued to be the focus of considerable interest in recent years because of the unparalleled improvement shown in mechanical, thermal, and electrical properties compared to the neat polymer. However, these improvements largely depend on the synthesis of well-exfoliated and high-quality GP. In this paper, we report a facile method for the production of GP sheets through the liquid-phase exfoliation of graphite in methanesulfonic acid (MSA). Raman, X-ray photoelectron and infrared spectroscopies reveal that the obtained GP has a low-defect density with a low degree of oxidation. Transmission electron microscopy and atomic force microscopy further confirm that the resulting GP is in the well-exfoliated state. Using this GP/MSA solution as a reaction solvent medium, polymer nanocomposites are prepared by in situpolymerization of poly [2,2′-(p-oxydiphenylene)-5,5′-bibenzimidazole] (OPBI). Compared to pure OPBI, the resulting OPBI/GP nanocomposites show simultaneously improved Young's modulus, tensile stress, toughness, storage modulus and thermal stability with the addition of extremely small amounts of GP. The high levels of reinforcement are attributed to the good dispersion and effective stress transfer between polymer and GP as evidenced by SEM images of the fracture surfaces, and the excellent intrinsic properties of the high-quality GP. All these features make this simple procedure a potential route for the fabrication of low-cost and high-performance polymer nanocomposites.
Co-reporter:Jialiang Wang, Zixing Shi, Jinchen Fan, Yu Ge, Jie Yin and Guoxin Hu
Journal of Materials Chemistry A 2012 - vol. 22(Issue 42) pp:NaN22466-22466
Publication Date(Web):2012/09/06
DOI:10.1039/C2JM35024F
Three-dimensional (3D) structures of graphene have attracted extensive interest for their practical applications, such as supercapacitors and catalyst supports. Self-assembly is a typical technique to fabricate macroscopic graphene materials integrated with various superior properties. However, an efficient and environmentally-friendly strategy is still needed. In this paper, we report a green and mild method for the synthesis of 3D architectures of graphene. This proposed method is based on the chemical reduction of graphene oxide (GO) with the aid of a range of natural phenolic acids and in situ self-assembly of graphene sheets via π–π interactions. The obtained monolithic graphene exhibits low density, super hydrophobicity, high porosity, excellent mechanical strength and electrical conductivity. These multifunctional products can be used as adsorbents for removal of oils, organic solvents and dyes from contaminated water, as well as electrode materials for supercapacitors.
Co-reporter:Jinchen Fan, Zixing Shi, Yu Ge, Jialiang Wang, Yan Wang and Jie Yin
Journal of Materials Chemistry A 2012 - vol. 22(Issue 27) pp:NaN13772-13772
Publication Date(Web):2012/04/18
DOI:10.1039/C2JM31437A
Gum arabic (GA), a natural polymer, is extensively used in food, drug, confectionery and soft drinks processing. In this paper, we present a green and facile approach for preparing graphene–Ag nanohybrids assisted by GA. In brief, GA functionalized graphene sheets (GA-G) were prepared by directly exfoliating graphite flakes in gum arabic (GA) aqueous solution with sonication. The yield of graphene exfoliation was systemically studied by varying the initial graphite concentration, GA concentration and sonication time. Furthermore, the GA functionalized graphene sheets–Ag nanoparticle hybrids (Ag/GA-G) were fabricated by adding AgNO3 aqueous solution into the GA-G water dispersion. The silver ions were directly reduced and immobilized on the surface of the GA-G nanosheets by GA. The Ag/GA-G hybrid materials can be used as suitable substrates of SERS for the detection of 4-aminothiophenol (4-ATP) at a detectable level of a concentration of 10−6 M in aqueous environments.
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