•HAMC hydrogel was crosslinked by PEG to prolong the residence time.•Rheological properties and injectability were improved by the addition of PEG.•PEG-crosslinked HAMC had more stable microstructure with interconnected pores.•Cell viability depended on the concentration of HAMC hydrogel.Spontaneous recovery ability of central nerves has inspired researchers to focus on tissue engineering techniques, especially scaffolds. To obtain a material with an appropriate degrading rate, an injectable composite hydrogel HAMC consisting of hyaluronic acid and methylcellulose was prepared using polyethylene glycol as a cross linker in this study. HAMC combined the advantages of two components to be fast-gelling, injectable, degradable, biocompatible, and it was able to meet some special shape requirement for injured tissue by in-situ forming. Moreover, due to the crosslinking effects polyethylene glycol brought to methylcellulose, the rheological properties and stability of HAMC were greatly improved, which could prolong the residence time of this hydrogel effectively. Cell viability results showed HAMC was cytocompatible for further applications in vivo, and would be a promising choice for neural tissue engineering in the future.

•MSN-reinforced pure Mg-matrix composites were produced by spark plasma sintering.•The strength of Mg-8wt%MSN increased by more than 30% compared to those of pure Mg.•The refined matrix and in-situ Mg2Si contributed to the strengthening effects.This study investigated, for the first time, the influences of mesoporous silica nanoparticle (MSN) in the magnesium (Mg) matrix on the mechanical properties. Sintered compacts of Mg-xMSN composites (x = 2, 4, 6, 8, 10 wt%) and pure Mg were fabricated by spark plasma sintering (SPS) after high-energy wet ball milling. Milled powders and sintered samples were characterized by XRD, SEM, TEM, hardness tester, and universal testing machine. Results revealed that ball milling significantly reduced the particle size of Mg. Densities of all the sintered samples were within 1.899 ± 0.003 g/cm3. Nanocrystallines were found in the sintered compacts. Mg-8wt%MSN exhibited the highest compressive strength of 414 ± 7.50 MPa, the highest bending strength of 210 ± 14.38 MPa, and the highest specific compressive strength of 217.88 N m/kg. These results indicated the invention of a new Mg-matrix composite with low density and high strength, for which the addition of MSN and the formation of rigid Mg2Si phase were mainly responsible.Download high-res image (300KB)Download full-size image

A layered aluminoborophosphate(LABP-DDA) was hydrothermally synthesized using dodecylamine as a structure-directing agent, and was added into polyamide 66(PA66) to obtain nanocomposites, PA66/LABP-DDA, via melt intercalation method. The characterization results of transmission electron microscopy(TEM) and small angle X-ray scattering (SAXS) indicate that LABP-DDA has been successfully exfoliated into nano-layers of PA66 matrix. The unstable γ phase of PA66 was found in the composites with the help of X-ray diffraction(XRD) and differential scanning calorimetry(DSC). The heterogeneous nucleation effect of LABP-DDA resulted in an increasement of about 10 °C in melting temperature and an increasement of about 7% in crystallinity when compared with those of neat PA66. The introduction of LABP-DDA did not significantly affect the toughness and strength of PA66. The results of flammability test indicate that LABP-DDA possesses positive synergistic flame retarding effect in the presence of melamine polyphosphate(MPP) and the 77%PA66/(23–x)%MPP/x%LABP-DDA(x=1, 2) samples in thickness of 1.6 mm reached from Fail to V-1 rating based on UL94, compared with 77%PA66/23%MPP.

We studied the synthesis of mesoporous silica from cetyltrimethyl ammonium bromide(CTAB) and sodium dodecyl sulfate(SDS) at different molar ratios(R). X-ray diffraction(XRD), scanning electron spectroscopy (SEM), transmission electron spectroscopy(TEM) and nitrogen sorption analysis were then used to further investigate the internal relationship among different morphologies and structures, as well as the mechanism of the transition from hexagonal to vesicular structure. The results reveal that as R increased, a consistent and gradual transition occurred via a concentric circular secondary structure formed. The antagonistic effect between the decreasing curvature of surfactant micelle and increasing curvature of secondary structures may be the reason for the complex morphologies synthesized, and the increasing bending energy ΔGb is the main driving force for the transition.

In this study, we exploit a facile, one-pot method to prepare MCM-41 type mesoporous silica nanoparticles decorated with silver nanoparticles (Ag-MSNs). Silver nanoparticles with diameter of 2–10 nm are highly dispersed in the framework of mesoporous silica nanoparticles. These Ag-MSNs possess an enhanced antibacterial effect against both Gram-positive and Gram-negative bacteria by preventing the aggregation of silver nanoparticles and continuously releasing silver ions for one month. The cytotoxicity assay indicates that the effective antibacterial concentration of Ag-MSNs shows little effect on human cells. This report describes an efficient and economical route to synthesize mesoporous silica nanoparticles with uniform silver nanoparticles, and these nanoparticles show promising applications as antibiotics.Keywords: antibacterial activity; continuously release; highly dispersity; mesoporous silica nanoparticles; silver nanoparticles

•We fabricated controllable multi-shell uniformed microspheres.•The multiple-layers of the spherical particles can be controllably prepared via multiple deposits in an alcohol solution system.•The temperature and the seeds mass effect on the morphologies of MSiO2/SSiO2 and MSiO2/SSiO2/SSiO2 via multiple-growth by coating solid silica layers.The preparation of controllable multi-shell nano and micro particles has great significance not only for their potential applications but also for fabricating novel composite functional advanced materials. In this paper, MSiO2, MTiO2 and SSiO2 with good monodispersity and no agglomeration among spheres have been synthesized successfully based on Stöber's method. MSiO2 were characterized as the silica with a worm-like mesopore structure and with uniform pore sizes of about 2.0 nm, and about 700 m2/g of specific surface area. A core–shell hybrid composite micron-sized spherical particle with multi-shell structures by using the synthesized MSiO2, MTiO2 and SSiO2 with a combination method has been designed and fabricated. The multiple-layers of these spherical particles can be controllably prepared via multiple deposits in an alcohol solution system, and the standard deviations of particle size of each sample are less than 3%. The temperature and the seeds mass effect on the morphologies of MSiO2/SSiO2 and MSiO2/SSiO2/SSiO2 via multiple-growth by coating solid silica layers have been investigated. In order to illustrate the sphere with multi-shell structure may have multi-functionalized, the MSiO2 sphere embedded methylene blue in the pores and coated with solid silica shell was fabricated.Scheme of the working method route. The SSiO2, the MSiO2 and MTiO2 were synthesized and either SSiO2, MSiO2 or MTiO2 were used as the seed beads to be coated with one or multiple different shells composed of either solid silica, mesoporous silica or mesoporous titanium oxide. Layer A: MSiO2, layer B: MTiO2, layer C: SSiO2, layer AC: MSiO2/SSiO2, layer CA: SSiO2/MSiO2, layer AB: MSiO2/MTiO2, ACC: MSiO2/SSiO2/SSiO2, ABC: MSiO2/MTiO2/SSiO2, CAB: SSiO2/MSiO2/MTiO2, AAA: MSiO2/MSiO2/MSiO2.

In this paper, an MCM-41 single crystal with hexagonal circular bicone form has been observed, and the special morphology of the single crystal appears to be a combination of circular bicone and hexagonal prism forms. As far as we know, the circular bicone faces have not been reported in crystal morphologies before. The results show that the morphology of MCM-41 single crystals remains essentially the same and can grow larger via the multiple-growth method in extremely dilute ammonia solution. Moreover, the morphology of the MCM-41 crystals can be effectively modulated by adding inorganic salts (KCl, NaCl) to the synthetic system. Increasing the concentration of the salts (KCl, NaCl) in the solution can make the aspect ratio and the conical angle vary consistently.

The preparation of large MCM-41 single crystals as well as their controllable morphologies has very important meanings not only for their potential applications but also for the exploration of the new morphogenetic mechanism for some special mesoporous crystals. In this paper, a novel crystal form of hexagonal circular bicone of MCM-41 crystal, which is the combination form of thee hexagonal bipyramid and circular bicone forms, has been observed. The MCM-41 single crystals which originally remained the same can grow larger to nearly ∼10 micron via multiple-growth in extremely diluted ammonia solution, and were characterized by SEM, POM, TEM, XRDetc. The morphology of the MCM-41 crystal can also be controllably modulated by adding alkali salts to the synthetic system. Increasing the concentration of KCl can cause the aspect ratio and the conical angle to increase consistently and the result displays monotonicity with a certain statistical deviation. A fluctuation effect has an influence on the surface energy and eventually leads to the evolution from a single crystal to one with non-crystalline characteristics.

Herein, we report the direct synthesis of micro–mesoporous silicas using unsaturated anionic surfactant α-linolenic acid as mesophase template. The self-assembly of α-linolenic acid, which could transform to a rigid mesophase template via inner-micellar polymerization when heated, was successfully leveraged to fabricate hydrothermally stable mesoporous silicas at high temperature, which retained a BET surface area of 678 m2 g−1 after hydrothermal treatment in boiling water for 5 days. Different analysis methods, e.g. X-ray diffraction, nitrogen physisorption, the non-local density functional theory (NLDFT) analysis and transmission electron microscopy, were employed to investigate the mesostructure of as-synthesized samples, which revealed a micro- and mesopores hybrid in one phase. 1H NMR was applied to characterize the α-linolenic acid micellar structure and confirmed that CC bonds have been opened up and polymerization occurred within micelles. The 29Si MAS NMR spectra indicated Q4 silicon is the dominating species, which explains well the high hydrothermal stability of the materials.Graphical abstractThe self-assembly of α-linolenic acid, which could transform to a rigid mesophase template via inner-micellar polymerization when heated, was successfully leveraged to fabricate hydrothermally stable mesoporous silicas at high temperature, which retained a BET surface area of 678 m2 g−1 after hydrothermal treatment in boiling water for 5 days. The 29Si MAS NMR spectra indicated Q4 silicon is the dominating species, which explains well the high hydrothermal stability of the materials.Research highlights► Direct synthesis of micro–mesoporous silicas under temperature higher than 180 °C using α-linolenic acid as template. ► Rigid template was formed via inner-micellar polymerization. ► High hydrothermal stability of the materials and the dominating Q4 silicon.

10–60 nm-sized mesoporous silica particles with ordered or worm-like pore structures were controllably synthesized in extremely dilute surfactant solution, and the lowest concentrations of TEOS and CTAB were 12.45 mM, 1.52 mM, respectively. The synthesis of nanometer-sized Al-incorporated mesoporous silica particles (Al-MS) was also performed under the similar conditions. Compared to the mesoporous silica without doping of aluminum, those Al-incorporated silica particles have a certain textural mesoporosity. The results indicate that the size and pore structure of mesoporous silica can be adjusted by changing the concentration of reactants. The mesoporous silica nanoparticles, including Al-MS, were characterized by transmission electron microscopy (TEM), small-angle X-ray diffraction (SAXRD), as well as nitrogen adsorption/desorption techniques. It was suggested that the formation of the mesoporous silica nanoparticles could be attributed to the deposition of self-assembled silicate micelles.

A novel host–guest approach to synthesize the hybrid AlPO4/nano-carbon (graphite-like) (AlPO4/NCG) material, in which it is composed of two steps: a hydrothermal synthesis of a new layer-structured AlPO4/Benzylamine and the preparation of AlPO4/NCG by calcinations at 873 K using this layer-structured material as precursor, was firstly presented. The layered structure of AlPO4/Benzylamine was verified by X-ray diffraction (XRD) and transmission electron microscopy (TEM) measurements, with a layer distance of 1.95 nm. And the layer-structured AlPO4/Benzylamine after calcinations was confirmed to be AlPO4/NCG via X-ray photoelectron spectroscopy (XPS) and Raman spectra measurement.

Bicontinuous mesoporous silica with hierarchical pore structure was obtained by self-assembly approach under biphasic oil–water system. The silica consists of two kinds of interconnecting pores with sizes of ca. 10 nm and ca. 40 nm, and has a surface area of 711 m2 g−1. By introducing the synthesized silica as matrix, novel composite gel electrolytes are fabricated, which show high ionic conductivity. The composite gel electrolyte could be used in both dye-sensitized solar cells (DSSCs) and lithium battery. Our results demonstrate that the quasi-solid state DSSC based on the novel composite electrolyte exhibits an encouraging overall efficiency of 4.31% at room temperature, and the lithium battery with sound capacity and capacity retention is also achieved.

In this paper, we systemically studied the evolution rules of morphologies of the extraordinary patterns including the flowerlike patterns of nanostructured cuprous oxide, which were synthesized by electrochemical deposition from a mixed solution of surfactant sodium dodecyl sulfate and copper sulfate, as well as that of the mesostructure along with the variation of the content of the SDS surfactant. The evolution of morphology was observed as follows: with the increment of surfactant, the morphologies of the deposited cuprous oxide were evolved from that with crystalline to noncrystalline characteristics. Concretely, as the surfactant increases, the crystalline face of the deposited crystal was initially sunken and then vanished. Consequently, the crystalline angles vanished; and finally the orientation of crystalline axis vanished too. Also, the rotational symmetry of patterns was replaced by the radial symmetry. Moreover, the templating effect of surfactant additives was employed to acquire different mesoscopic structured growth units that also affect the macroscopic shape and microscopic order of the cuprous oxide. On the basis of the combination of self-assembly analysis and interfacial dynamics, the reason for formatting interesting and unusual patterns, such as flower patterns of nanostructured cuprous oxide, was explained. In particular, the formation can be rationalized by the modulation of electric field as an immaterial template which determins the macroscopic shape along with the assistance of surfactant self-assembly in molding the nanoscale structures.

Using diethyl ether as a co-solvent, a non-stable interface of biphasic oil–water system (the so-called oil–water two-phase (OWTP) system) was employed in the preparation of mesostructured silicas with diversified particle morphologies. By adjusting the molar ratios of H2O:C2H5OC2H5:NH3 · H2O and the alkalinity of the OWTP system, several product morphologies could be obtained under different reaction conditions. On the other hand, different product morphologies with distinct structural properties could be obtained at a specific reaction condition, indicating that product morphology varied upon intrinsic characteristics of non-equilibrium processes in the system as well. There are six kinds of product morphologies in our results. In the biphasic region the morphotypes such as vesicles, slices, and spheres were widely distributed. Multi-lamellar fragments were formed under relatively strong alkaline conditions and at a high proportion of diethyl ether (>41%). bi-continuously phased fragments were observed in the weak alkaline conditions and medium proportion between diethyl ether and water. In the single-phase region, hexagonally ordered MCM-41, plain sheets of MCM-48, as well as smooth and plain slices with worm-like pore structures were formed with bi-modal pore-size distribution structure. Based on HRTEM analysis, these structural features were rationalized being derived from fragments that originated from the oil/water interface. Apparently, the product morphosynthesis resulted from a combination of fluid rheological distortions and reconstructive reaction fields. With a systematic approach we have established the reaction phase diagram of the system, which enabled us to define the structural properties and to classify the morphology of the products for nomenclatural purposes in studying OWTP systems.

Mesoporous silica vesicles with controllable morphologies are successfully synthesized by the sol-gel method. The multi-lamellar structured products were obtained through assembly between a single-chain cationic surfactant of hexadecyltrimethyl ammonium bromide (CTAB) and silica precursors under the auxiliary of proper amount of diethyl ether. Snail-like, star-like and sharp-edged bowl-like morphologies were observed separately in the synthesized silica vesicles with the concentration of diethyl ether increased. The synthesis procedure provides a simple method to prepare vesicle-like materials.