Co-reporter:Xutong Yang, Lin Tang, Yongqiang Guo, Chaobo Liang, Qiuyu Zhang, Kaichang Kou, Junwei Gu
Composites Part A: Applied Science and Manufacturing 2017 Volume 101(Volume 101) pp:
Publication Date(Web):1 October 2017
DOI:10.1016/j.compositesa.2017.06.005
The proposed combining method of silane coupling agent of γ-aminopropyl triethoxy silane/aminopropyllsobutyl polyhedral oligomeric silsesquioxane (KH-560/NH2-POSS) was performed to functionalize the surface of hexagonal nanometer boron nitride fillers (f-nBN), aiming to fabricate the f-nBN/polyphenylene sulfide (f-nBN/PPS) nanocomposites with excellent thermal conductivities, outstanding thermal stabilities and optimal dielectric properties. The usage of f-nBN fillers was benifit for improving the thermally conductive coefficient (λ) and decreasing dielectric constant (ε) values of the PPS nanocomposites. The f-nBN/PPS nanocomposite with 60 wt% f-BN fillers was an excellent dielectric nanocomposite with high λ & ideal ε values and outstanding thermal stability, λ of 1.122 W/m K (increased by 400% compared to that of pristine PPS matrix), ε of 3.99 and THeat-resistance index (THRI) beyond 275 °C, which holds potential for electronic packaging materials and ultra high voltage electrical apparatus.
Co-reporter:Chaobo Liang, Ping Song, Hongbo Gu, Chao Ma, Yongqiang Guo, Hongyuan Zhang, Xiaojiang Xu, Qiuyu Zhang, Junwei Gu
Composites Part A: Applied Science and Manufacturing 2017 Volume 102(Volume 102) pp:
Publication Date(Web):1 November 2017
DOI:10.1016/j.compositesa.2017.07.030
Fluorescent epoxy nanocomposites reinforced with polydopamine (PDA) functionalized zinc oxide (ZnO) nanoparticles have been obtained. Results reveal that the PDA functionalized ZnO nanoparticles are dispersed uniformly in the epoxy nanocomposites. The enhanced tensile strength of the epoxy nanocomposites filled with PDA functionalized ZnO nanoparticles (up to 106.7 MPa) is obtained compared with that of pure epoxy (83.8 MPa) and epoxy nanocomposites filled with the same loading pristine ZnO nanoparticles (around 91.5 MPa). The glass transition temperature (Tg) of the epoxy nanocomposites filled with PDA functionalized ZnO nanoparticles has shifted to a higher temperature (127.0–132.0 °C) compared with that of pure epoxy (118.3 °C). The interaction between PDA and epoxy matrix is also explored by Fourier transform infrared (FTIR) and contact angle. The introduction of PDA can enhance the mechanical and thermal properties of epoxy nanocomposites without damaging the fluorescent property of ZnO nanoparticles.The enhanced thermal mechanical property has been obtained in the nanodopamine coupled fluorescent nanozinc oxide reinforced epoxy nanocomposites.Download high-res image (160KB)Download full-size image
Co-reporter:Fei Fan;Bin Zhang;Yaming Cao;Xutong Yang;Yu Chen
Nanoscale (2009-Present) 2017 vol. 9(Issue 30) pp:10610-10618
Publication Date(Web):2017/08/03
DOI:10.1039/C7NR02809A
Zero dimensional graphene oxide (GO) quantum dots (GOQDs) have been expected to play an important role in the development of new memory materials. When the size of GO was reduced to that of GOQDs, both the electron affinity and ionization potential of GO were found to be decreased, and this was followed by the elevation of lowest energy unoccupied molecular orbital (LUMO) energy level. This implies that the electron withdrawing ability of GOQDs is weaker than that of GO. In this work, a novel arylamine-based polyazomethine covalently functionalized graphene oxide quantum dots (TPAPAM-GOQDs), which was synthesized using an amidation reaction, was for the first time used to fabricate a ternary memory device with a configuration of gold/TPAPAM-GOQDs/indium tin oxide. The current ratio of OFF : ON-1 : ON-2 was found to be 1 : 60 : 3000. Its conductive nature was also revealed using an in situ conductive atomic force microscopy technique. This memory device could potentially increase the memory capacity of the device from the conventional 2n to 3n when compared to binary memory devices.
Co-reporter:Yongxi Li;Minchao Gu;Zhe Pan;Bin Zhang;Xutong Yang;Yu Chen
Journal of Materials Chemistry A 2017 vol. 5(Issue 22) pp:10798-10814
Publication Date(Web):2017/06/06
DOI:10.1039/C7TA02562A
Harvesting energy directly from sunlight using photovoltaic technology has become an essential component of future global energy production. Although silicon-based inorganic materials still play a dominant role in the market, problems for inorganic materials-based solar cells mainly lie in (1) the high cost of production and technical difficulties in the fabrication of large-area cells and (2) supply of highly purified silicon. In contrast to inorganic photovoltaic materials, organic/polymer photovoltaic materials have currently become of broader interest owing to their great potential to bring about a major breakthrough in reducing the cost of solar cells. As a promising building block to construct narrow bandgap semiconductors for high-efficiency photovoltaics, structurally well-defined indacenodithiophene (IDT) and its derivatives have inspired great interest in the industrial and academic communities over recent years due to their rigidified and tunable coplanar fused ring aromatic structures, and 3D conformation as well. The aromatic fused-ring blocks efficiently restrain rotational disorder and consequently lower reorganization energy. An encouraging power conversion efficiency of more than 12% has been achieved in the IDT-based polymer solar cells. This review surveys recent research advances in the area of IDT-based conjugated materials for photovoltaic applications. The factors affecting the bandgaps, molecular energy levels, film morphologies, as well as the photovoltaic performance of these materials have also been discussed.
Co-reporter:Hongbo Gu;Chao Ma;Chaobo Liang;Xudong Meng;Zhanhu Guo
Journal of Materials Chemistry C 2017 vol. 5(Issue 17) pp:4275-4285
Publication Date(Web):2017/05/04
DOI:10.1039/C7TC00437K
Transparent epoxy composites strengthened and toughened by thermoplastic polystyrene grafted with epichlorohydrin (g-PS) have been prepared at low loading levels. The polymer backbone of PS was manipulated by the epoxide and hydroxyl groups confirmed by Fourier transform infrared spectroscopy (FT-IR), thermogravimetric analysis (TGA), and X-ray photoelectron spectroscopy (XPS). Contact angle and differential scanning calorimetry (DSC) tests indicated that the grafting process could decrease the surface tension and increase the compatibility between PS and epoxy resins. The effects of g-PS loading and the grafting process on both the viscosity of liquid epoxy resin suspensions as well as the physicochemical properties of cured epoxy composites have been systematically investigated. The cured g-PS/epoxy composites demonstrated an enhanced tensile strength (maximum of 97.4 MPa) compared to either cured pure epoxy (77.6 MPa) or PS/epoxy composites (79.1 MPa). The modulus of toughness for g-PS/epoxy composites reaches values of up to 355.9 MJ m−3, which is respectively 176.6 and 141.1% higher than those for cured pure epoxy and PS/epoxy composites. The uniform g-PS distribution in the cured g-PS/epoxy composites was observed by scanning electron microscope (SEM). The glass transition temperature (Tg) of cured g-PS/epoxy composites was shifted to a higher temperature (increased by 16.3 °C) in the dynamic mechanical analysis (DMA) compared with that of cured pure epoxy (111.7 °C). The strong interfacial interaction obtained between g-PS and the epoxy matrix was responsible for the enhanced mechanical and thermal mechanical properties. This work provides a new insight into the investigation of interaction and compatibility between thermoplastic and thermoset materials.
Co-reporter:Junjun Feng;Jian Li;Lixin Chen;Yaosong Qin;Xiaofei Zhang
Journal of Polymer Research 2017 Volume 24( Issue 11) pp:176
Publication Date(Web):03 October 2017
DOI:10.1007/s10965-017-1338-9
4-hydroxymethyl phenylboronic acid (4-HMPBA), phenol and formaldehyde were for the first time to synthesize boron containing novolac phenolic resins (Novolac-4-HMPBA). Its corresponding carbon fibers (CF) composites were also fabricated via the lamination followed by hot-compression. Results revealed that Novolac-4-HMPBA was successfully synthesized. Compared to common novolac phenolic resin (NPR), the corresponding decomposition temperature of 5% weight loss (T5) and char yield at 800 °C (C800) of cured Novolac-4-HMPBA-30 were increased to 369.1 °C and 69.7%, increased by 41.3% and 26.3%, respectively. The CF/Novolac-4-HMPBA-20 composites presented relatively higher interlaminar shear strength (ILSS) of 35.9 MPa, increased by 50.2% compared to that of CF/NPR composites. After the treatment at 800 °C for one hour under Ar atmosphere, the corresponding ILSS value of CF/Novolac-4-HMPBA-20 composite was decreased to 7.8 MPa, but still higher than that of CF/NPR composites (3.0 MPa).
Co-reporter:Hongbo Gu, Chao Ma, Junwei Gu, Jiang Guo, Xingru Yan, Jiangnan Huang, Qiuyu Zhang and Zhanhu Guo
Journal of Materials Chemistry A 2016 vol. 4(Issue 25) pp:5890-5906
Publication Date(Web):12 May 2016
DOI:10.1039/C6TC01210H
Epoxy is a crucial engineered thermosetting polymer with wide industrial applications in adhesive, electronics, aerospace and marine systems. In this review, basic knowledge of epoxy resins and the challenge for the preparation of epoxy nanocomposites are summarized. The state-of-art multifunctional epoxy nanocomposites with magnetic, electrically conductive, thermally conductive, and flame retardant properties of the past few years are critically reviewed with detailed examples. The applications of epoxy nanocomposites in aerospace, automotives, anti-corrosive coatings, and high voltage fields are briefly summarized. This knowledge will have great impact on the field and will facilitate researchers in seeking new functions and applications of epoxy resins in the future.
Co-reporter:Chunmei Li, Jiaojun Tan, Junwei Gu, Lei Qiao, Baoliang Zhang, Qiuyu Zhang
Composites Science and Technology 2016 Volume 123() pp:250-258
Publication Date(Web):8 February 2016
DOI:10.1016/j.compscitech.2016.01.001
We report an efficient and novel method for encapsulation of isophorone diisocyanate (IPDI) in polythioether microcapsules via thiol-ene click reaction based on Pickering emulsion, which has significantly improved and simplified the preparation process. The resultant microcapsules have spherical shapes with a layer of poly(glycidyl methacrylate) (PGMA) particles covering outside. The diameter ranges from 82.1 to 160.8 μm, which is controlled by the concentration of PGMA particles, and the typical shell thickness is about 9 μm. Moreover, the core content is up to 71% by adjusting the adding ratio of core/shell monomers. Remarkably, the microcapsules have excellently environmental stability that only 18% of the core content drops (from 63.2% to 51.8%) after immersion in water for seven days. These microcapsules could keep their integrity and uniformly disperse in acrylate coatings. In addition, they are proved to be a good self-healing candidate for coatings applied in wet environment.
Co-reporter:Yusheng Tang, Shuang Xu, Yunchuan Xie, Junwei Gu, Zhimei Song, Feng Gao, Jie Kong
Composites Science and Technology 2016 Volume 124() pp:10-16
Publication Date(Web):1 March 2016
DOI:10.1016/j.compscitech.2016.01.006
Surface initiated reversible addition–fragmentation chain transfer polymerization (RAFT) of glycidyl methacrylate (GMA) was conducted on ceramic particles (ZNT). Then the ZNT@PGMA particles were introduced into cyanate ester (CE) matrix to prepare the ultra low dielectric loss ZNT@PGMA/CE composites. The ZNT@PGMA particles can be well dispersed in the CE matrix, resulting in the improvement of glass transition temperature by 40 °C and the increase of storage modulus by 130% in comparison to that of pure CE resins. The introduction of ZNT@PGMA particles can obviously decrease dielectric loss value of the ceramic/CE composites by one order of magnitude, which possesses potential in wave transparent composites and structures.
Co-reporter:Lidong Tian;Xingfeng Lei;Zhaoyuan Lv;Mingtao Qiao;Changjie Yin ;Qiuyu Zhang
Macromolecular Materials and Engineering 2016 Volume 301( Issue 5) pp:625-635
Publication Date(Web):
DOI:10.1002/mame.201600013
Co-reporter:Junwei Gu, Chaobo Liang, Jing Dang, Wencai Dong and Qiuyu Zhang
RSC Advances 2016 vol. 6(Issue 42) pp:35809-35814
Publication Date(Web):31 Mar 2016
DOI:10.1039/C6RA04513H
Silane coupling reagent γ-glycidoxy propyl trimethoxy silane/polyhedral oligomeric silsesquioxane (KH-560/POSS) functionalized nanosized boron nitride (POSS-g-nBN) fillers were performed to fabricate thermally conductive bismaleimide/diallylbisphenol A (BMI/DABA) nanocomposites combining excellent dielectric properties and outstanding thermal stability. POSS molecules have been grafted on the surface of the nBN fillers. The POSS-g-nBN/BMI/DABA nanocomposite with 15.4 vol% POSS-g-nBN is an excellent dielectric composite material with high thermal conductivity and outstanding thermal stability; the corresponding dielectric constant ε is 3.42, the dielectric loss factor tanδ is 0.0085, the thermally conductive coefficient λ is 0.607 W m−1 K−1 (increased by 266% compared to that of pure BMI/DABA), and the 5 wt% thermal weight loss temperature (T5) reaches up to 428 °C, which holds potential for use in the integration and the miniaturization of microelectronic devices.
Co-reporter:Junwei Gu, Xutong Yang, Chunmei Li, and Kaichang Kou
Industrial & Engineering Chemistry Research 2016 Volume 55(Issue 41) pp:10941
Publication Date(Web):September 30, 2016
DOI:10.1021/acs.iecr.6b03093
Bisphenol A cyanate ester/polyglycidyl methyacrylate (BADCy/PGMA) microcapsules were successfully fabricated via a solvent evaporation technique; herein, BADCy is the core material and synthesized PGMA is the shell material. Optimal BADCy/PGMA microcapsules with dense core–shell structures were implanted in the bisphenol A epoxy resin (E-51) matrix to fabricate the corresponding (BADCy/PGMA)/E-51 self-healing composites. Results revealed that the optimal BADCy/PGMA microcapsules presented a spherical shape and rough surface, with mean diameter of 31.5 μm and wall thickness of 2.2 μm. The core material of BADCy maintained its reactivity after being encapsulated by the shell of PGMA. The BADCy/PGMA microcapsules also presented relatively good thermal stability and proper mechanical stability. Moreover, the fabricated (BADCy/PGMA)/E-51 composite with 8 wt % BADCy/PGMA microcapsules possessed relatively good self-healing performance.
Co-reporter:Xingru Yan, Junwei Gu, Guoqiang Zheng, Jiang Guo, Alexandra Maria Galaska, Jingfang Yu, Mojammel Alam Khan, Luyi Sun, David P. Young, Qiuyu Zhang, Suying Wei, Zhanhu Guo
Polymer 2016 Volume 103() pp:315-327
Publication Date(Web):26 October 2016
DOI:10.1016/j.polymer.2016.09.056
•Copolymer nanocomposites were prepared by coating carbon nanotubes on the surface of gelated polymer pellets.•Electrical conductivity was observed to depend on the pressing temperature and CNT loading level.•Variable range hopping (VRH) mechanistic study revealed a 3-d electron transport mechanism.•Both unique positive and negative magnetoresistance (MR) phenomena were observed and analyzed by two different models.High electrical conductivity in ethylene/1-octene copolymers (EOCs) was achieved by sticking CNTs onto the gelated EOCs pellet surface and the subsequent hot pressing. The electrical conductivity (σ) was observed to be dependent on the pressing temperature and the CNT loading. Variable range hopping (VRH) mechanistic study revealed a 3-d electron transport mechanism. Both unique positive and negative magnetoresistance (MR) phenomena were observed in these polymer nanocomposites (PNCs) and theoretically analyzed by two different models (wave-function shrinkage model for positive GMR vs. forward interference model for negative GMR). Other properties were tested and analyzed as well. Neat EOCs and their nanocomposites exhibited both Newtonian and shear thinning behaviors under melting state. Less internal chain-chain friction heat was generated than that of neat EOCs after applying the same oscillation frequencies. The increased thermal stability of EOC nanocomposites was observed with increasing the CNTs loading. An increased thermal conductivity (λ) was observed arising from the formed CNTs network.
Co-reporter:Yusheng Tang;Yuanxun Yu ;Jie Kong
Polymer Composites 2015 Volume 36( Issue 11) pp:2017-2021
Publication Date(Web):
DOI:10.1002/pc.23111
Quartz fibers (QFs) and two polyhedral oligomeric silsesquioxane (POSS) (epoxy-POSS and hydroxy-POSS) are performed to regulate the dielectric properties, heat resistance, and mechanical properties of cyanate ester (CE) resins. With the introduction of POSS, the dielectric constant and dielectric loss tangent values of the POSS/QFs/CE laminated composites are decreased obviously. The heat resistance properties and flexural strength values of the laminated composites are increased, but the interlaminar shear strength values of the laminated composites are decreased slightly. The EP-POSS/QFs/CE laminated composites have relatively better dielectric, heat resistance, and mechanical properties than those of HO-POSS/QFs/CE laminated composites. POLYM. COMPOS., 36:2017–2021, 2015. © 2014 Society of Plastics Engineer
Co-reporter:Junwei Gu, Zhaoyuan Lv, Yalan Wu, Ruoxi Zhao, Lidong Tian, Qiuyu Zhang
Composites Part A: Applied Science and Manufacturing 2015 Volume 79() pp:8-13
Publication Date(Web):December 2015
DOI:10.1016/j.compositesa.2015.09.005
Silicon carbide particle/polystyrene (SiCp/PS) electrospun mats are firstly prepared by electrospinning technology, then to be fabricated the corresponding thermally conductive SiCp/PS composites by the method of “laminating-hot press”. The mass fraction of SiCp and laminating mode of SiCp/PS electrospun mats affecting on the thermal conductivities, dielectric and thermal properties of the composites are investigated. The addition of 32.8 vol% SiCp improves the thermally conductive coefficient λ of pure PS from 0.182 to 0.566 W/m K and thermal diffusivity of pure PS from 0.169 to 0.376 mm2/s, whereas the dielectric constant values still remain at relatively low levels. The thermal stabilities of the SiCp/PS composites are increased with the increasing addition of SiCp. For a given SiCp loading, the SiCp/PS composites from warp–weft arrangement of SiCp/PS electrospun mats possess relative higher thermally conductive coefficient λ and dielectric constant values than those of SiCp/PS composites from warp–warp arrangement of SiCp/PS electrospun mats.
Co-reporter:Wanlu Sun;Lidong Tian;Pan Yao;Qiuyu Zhang
Journal of Polymer Research 2015 Volume 22( Issue 5) pp:
Publication Date(Web):2015 May
DOI:10.1007/s10965-015-0735-1
A series of PEPA-TAP-ODA-6FDA branched phenylethynyl-terminated polyimides (BPIs) are successfully synthesized by incorporation of branching units into the linear PI. The molecular structures, thermal and rheological properties of the BPIs are investigated and characterized by FTIR, 1H NMR, elemental analysis, TGA and rheological test. All the BPIs exhibit high transparent in visible region, high solubility, excellent thermal stabilities and melting processability. All the BPIs have excellent thermal stabilities, and the corresponding T5 and heat resistance index values of the BPIs are all higher than 470 and 265 °C, respectively. All the BPIs have a relatively lower melt viscosity values. Compared to that of neat PI, the minimum melt viscosity values of the BPIs are all decreased obviously. Herein, BPIs-b exhibits the minimum melt viscosity (210 Pa•s), far below than that of neat PI (1260 Pa•s).
Co-reporter:Junwei Gu;Ting Bai;Jing Dang;Junjun Feng ;Qiuyu Zhang
Polymer Composites 2014 Volume 35( Issue 3) pp:611-616
Publication Date(Web):
DOI:10.1002/pc.22702
A novel “three-step approach” of methanesulfonic acid/γ-aminopropyl triethoxy silane/GlycidylEthyl polyhedral oligomeric silsesquioxane (MSA/KH550/POSS) was proposed to functionalize the surface of high modulus poly (p-phenylene-2,6-benzobisoxazole) (HMPBO) fibers. Results indicated that GlycidylEthyl POSS was successfully grafted on the surface of HMPBO fibers and the surface roughness of HMPBO fibers was increased obviously. The single fiber pull-out strength of POSS-g-HMPBO/epoxy resin microcomposite was improved to 1.19 MPa, better than that of native HMPBO/epoxy resin microcomposite. POLYM. COMPOS., 35:611–616, 2014. © 2013 Society of Plastics Engineers
Co-reporter:Junwei Gu;Chao Xie;Hailin Li;Jing Dang;Wangchang Geng;Qiuyu Zhang
Polymer Composites 2014 Volume 35( Issue 6) pp:1087-1092
Publication Date(Web):
DOI:10.1002/pc.22756
The volume fraction of functionalized graphene nanoplatelets (GNPs) influencing on the thermal conductivities of GNPs/polyphenylene sulfide (GNPs/PPS) composites are investigated. Results reveal that a great improvement of the thermal conductivities with the addition of functionalized GNPs, and the thermal conductivity of the GNPs/PPS composite is 4.414 W/mK with 29.3 vol% functionalized GNPs, 19 times higher than that of the pure PPS matrix. The significantly high improvement of the thermal conductivities is ascribed to good thermal transmission through GNPs networks in the PPS matrix, following a thermal percolation behavior. Meantime, the GNPs have strong ability to generate continuous thermally conductive chains, and the formation of thermally conductive networks becomes much easier. POLYM. COMPOS., 35:1087–1092, 2014. © 2013 Society of Plastics Engineers
Co-reporter:Hailin Li;Yusheng Tang;Jing Dang;Ting Bai;Junjun Feng
Polymer Composites 2013 Volume 34( Issue 12) pp:2026-2030
Publication Date(Web):
DOI:10.1002/pc.22610
The surface of high modulus poly(p-phenylene-2,6-benzobisoxazole) (HMPBO) fibers were treated by the combination method of oxygen plasma/polyhedral oligomeric silsesquioxane (POSS). The chemical compositions and surface morphologies of HMPBO fibers were characterized by Fourier transform infrared, X-ray photoelectron spectroscopy, thermogravimetric analyzer, and scanning electron microscopy. The interfacial shearing strength (IFSS) of the HMPBO/cyanate ester (HMPBO/CE) micro-composites was measured by single fiber pull out test. Results showed that the POSS was grafted on the surface of HMPBO fibers, and the grafting amount was about 0.82 wt%. After the treatment, the HMPBO fibers became coarser and the diameter was also increased. Compared with that of pure HMPBO/CE micro-composites, the IFSS of treated HMPBO/CE micro-composites was increased by 20.7%. POLYM. COMPOS., 34:2026–2030, 2013. © 2013 Society of Plastics Engineers
Co-reporter:Junwei Gu;Qiuyu Zhang;Jing Dang;Chao Xie
Polymers for Advanced Technologies 2012 Volume 23( Issue 6) pp:1025-1028
Publication Date(Web):
DOI:10.1002/pat.2063
Boron nitride (BN) micro particles modified by silane coupling agent, γ-aminopropyl triethoxy silane (KH550), are employed to prepare BN/epoxy resin (EP) thermal conductivity composites. The thermal conductivity coefficient of the composites with 60% mass fraction of modified BN is 1.052 W/mK, five times higher than that of native EP (0.202 W/mK). The mechanical properties of the composites are optimal with 10 wt% BN. The thermal decomposition temperature, dielectric constant, and dielectric loss increase with the addition of BN. For a given BN loading, the surface modification of BN by KH550 exhibits a positive effect on the thermal conductivity and mechanical properties of the BN/EP composites. Copyright © 2011 John Wiley & Sons, Ltd.
Co-reporter:Yusheng Tang;Ting Bai
Fibers and Polymers 2012 Volume 13( Issue 10) pp:1249-1253
Publication Date(Web):2012 December
DOI:10.1007/s12221-012-1249-7
The silane coupling agent of γ-aminopropyl triethoxy silane combined with ultrasonic vibration was employed to modify the surface of high modulus poly (p-phenylene-2, 6-benzobisoxazole) (HMPBO) fibers. The results showed that polar hydroxyl groups were successfully introduced on the HMPBO surface. The contact angles on HMPBO fibers both for water (θwater) and for glycol (θglycol) gradually were decreased, and the surface roughness of HMPBO fibers was also increased. Meanwhile, the single fiber pull-out strength of HMPBO was increased accordingly.
Co-reporter:Junwei Gu, Zhaoyuan Lv, Yalan Wu, Yongqiang Guo, Lidong Tian, Hua Qiu, Wanzheng Li, Qiuyu Zhang
Composites Part A: Applied Science and Manufacturing (March 2017) Volume 94() pp:
Publication Date(Web):March 2017
DOI:10.1016/j.compositesa.2016.12.014
Micrometer boron nitride/polyamide acid (mBN/PAA) compound was firstly fabricated via in-situ polymerization, performed to obtain the mBN/PAA electrospun fibers by electrospinning technology, finally to fabricate the dielectric thermally conductive mBN/polyimide (mBN/PI) composites via thermal-imidization followed by hot press method. The obtained mBN/PI composite with 30 wt% mBN presents relatively highly thermally conductive coefficient (λ), excellent dielectric constant (ε) & dielectric loss tangent (tan δ), and extremely outstanding thermal stability, λ of 0.696 W/m K, ε of 3.77, tan δ of 0.007, THeat-resistance index (THRI) of 279 °C and glass transition temperature (Tg) of 240 °C, which presents a great potential for packaging in integration and miniaturization of microelectronic devices.
Co-reporter:Junwei Gu, Chaobo Liang, Xiaomin Zhao, Bin Gan, Hua Qiu, Yonqiang Guo, Xutong Yang, Qiuyu Zhang, De-Yi Wang
Composites Science and Technology (8 February 2017) Volume 139() pp:83-89
Publication Date(Web):8 February 2017
DOI:10.1016/j.compscitech.2016.12.015
Co-reporter:Yongxi Li, Minchao Gu, Zhe Pan, Bin Zhang, Xutong Yang, Junwei Gu and Yu Chen
Journal of Materials Chemistry A 2017 - vol. 5(Issue 22) pp:NaN10814-10814
Publication Date(Web):2017/05/08
DOI:10.1039/C7TA02562A
Harvesting energy directly from sunlight using photovoltaic technology has become an essential component of future global energy production. Although silicon-based inorganic materials still play a dominant role in the market, problems for inorganic materials-based solar cells mainly lie in (1) the high cost of production and technical difficulties in the fabrication of large-area cells and (2) supply of highly purified silicon. In contrast to inorganic photovoltaic materials, organic/polymer photovoltaic materials have currently become of broader interest owing to their great potential to bring about a major breakthrough in reducing the cost of solar cells. As a promising building block to construct narrow bandgap semiconductors for high-efficiency photovoltaics, structurally well-defined indacenodithiophene (IDT) and its derivatives have inspired great interest in the industrial and academic communities over recent years due to their rigidified and tunable coplanar fused ring aromatic structures, and 3D conformation as well. The aromatic fused-ring blocks efficiently restrain rotational disorder and consequently lower reorganization energy. An encouraging power conversion efficiency of more than 12% has been achieved in the IDT-based polymer solar cells. This review surveys recent research advances in the area of IDT-based conjugated materials for photovoltaic applications. The factors affecting the bandgaps, molecular energy levels, film morphologies, as well as the photovoltaic performance of these materials have also been discussed.
Co-reporter:Hongbo Gu, Chao Ma, Junwei Gu, Jiang Guo, Xingru Yan, Jiangnan Huang, Qiuyu Zhang and Zhanhu Guo
Journal of Materials Chemistry A 2016 - vol. 4(Issue 25) pp:NaN5906-5906
Publication Date(Web):2016/05/12
DOI:10.1039/C6TC01210H
Epoxy is a crucial engineered thermosetting polymer with wide industrial applications in adhesive, electronics, aerospace and marine systems. In this review, basic knowledge of epoxy resins and the challenge for the preparation of epoxy nanocomposites are summarized. The state-of-art multifunctional epoxy nanocomposites with magnetic, electrically conductive, thermally conductive, and flame retardant properties of the past few years are critically reviewed with detailed examples. The applications of epoxy nanocomposites in aerospace, automotives, anti-corrosive coatings, and high voltage fields are briefly summarized. This knowledge will have great impact on the field and will facilitate researchers in seeking new functions and applications of epoxy resins in the future.
Co-reporter:Hongbo Gu, Chao Ma, Chaobo Liang, Xudong Meng, Junwei Gu and Zhanhu Guo
Journal of Materials Chemistry A 2017 - vol. 5(Issue 17) pp:NaN4285-4285
Publication Date(Web):2017/03/28
DOI:10.1039/C7TC00437K
Transparent epoxy composites strengthened and toughened by thermoplastic polystyrene grafted with epichlorohydrin (g-PS) have been prepared at low loading levels. The polymer backbone of PS was manipulated by the epoxide and hydroxyl groups confirmed by Fourier transform infrared spectroscopy (FT-IR), thermogravimetric analysis (TGA), and X-ray photoelectron spectroscopy (XPS). Contact angle and differential scanning calorimetry (DSC) tests indicated that the grafting process could decrease the surface tension and increase the compatibility between PS and epoxy resins. The effects of g-PS loading and the grafting process on both the viscosity of liquid epoxy resin suspensions as well as the physicochemical properties of cured epoxy composites have been systematically investigated. The cured g-PS/epoxy composites demonstrated an enhanced tensile strength (maximum of 97.4 MPa) compared to either cured pure epoxy (77.6 MPa) or PS/epoxy composites (79.1 MPa). The modulus of toughness for g-PS/epoxy composites reaches values of up to 355.9 MJ m−3, which is respectively 176.6 and 141.1% higher than those for cured pure epoxy and PS/epoxy composites. The uniform g-PS distribution in the cured g-PS/epoxy composites was observed by scanning electron microscope (SEM). The glass transition temperature (Tg) of cured g-PS/epoxy composites was shifted to a higher temperature (increased by 16.3 °C) in the dynamic mechanical analysis (DMA) compared with that of cured pure epoxy (111.7 °C). The strong interfacial interaction obtained between g-PS and the epoxy matrix was responsible for the enhanced mechanical and thermal mechanical properties. This work provides a new insight into the investigation of interaction and compatibility between thermoplastic and thermoset materials.
![2-[methyl[(tridecafluorohexyl)sulphonyl]amino]ethyl acrylate](http://img.cochemist.com/ccimg/67600/67584-57-0.png)
![2-[methyl[(tridecafluorohexyl)sulphonyl]amino]ethyl acrylate](http://img.cochemist.com/ccimg/67600/67584-57-0_b.png)
![Poly(benzo[1,2-d:5,4-d']bisoxazole-2,6-diyl-1,4-phenylene)](http://img.cochemist.com/ccimg/60900/60871-72-9.png)
![Poly(benzo[1,2-d:5,4-d']bisoxazole-2,6-diyl-1,4-phenylene)](http://img.cochemist.com/ccimg/60900/60871-72-9_b.png)
