|
Multi-scale simulations of apatite–collagen composites: from molecules to materials
Dirk ZAHN
Front. Mater. Sci.. 2017, 11 (1): 1-12.
https://doi.org/10.1007/s11706-017-0370-3
We review scale-bridging simulation studies for the exploration of atomic-to-meso scale processes that account for the unique structure and mechanic properties of apatite–protein composites. As the atomic structure and composition of such complex biocomposites only partially is known, the first part (i) of our modelling studies is dedicated to realistic crystal nucleation scenarios of inorganic–organic composites. Starting from the association of single ions, recent insights range from the mechanisms of motif formation, ripening reactions and the self-organization of nanocrystals, including their interplay with growth-controlling molecular moieties. On this basis, (ii) reliable building rules for unprejudiced scale-up models can be derived to model bulk materials. This is exemplified for (enamel-like) apatite–protein composites, encompassing up to 106 atom models to provide a realistic account of the 10 nm length scale, whilst model coarsening is used to reach µm length scales. On this basis, a series of deformation and fracture simulation studies were performed and helped to rationalize biocomposite hardness, plasticity, toughness, self-healing and fracture mechanisms. Complementing experimental work, these modelling studies provide particularly detailed insights into the relation of hierarchical composite structure and favorable mechanical properties.
Figures and Tables |
References |
Related Articles |
Metrics
|
|
Fabrication and characterization of Antheraea pernyi silk fibroin-blended P(LLA-CL) nanofibrous scaffolds for peripheral nerve tissue engineering
Juan WANG,Binbin SUN,Muhammad Aqeel BHUTTO,Tonghe ZHU,Kui YU,Jiayu BAO,Yosry MORSI,Hany EL-HAMSHARY,Mohamed EL-NEWEHY,Xiumei MO
Front. Mater. Sci.. 2017, 11 (1): 22-32.
https://doi.org/10.1007/s11706-017-0368-x
Electrospun nanofibers have gained widespreading interest for tissue engineering application. In the present study, ApF/P(LLA-CL) nanofibrous scaffolds were fabricated via electrospinning. The feasibility of the material as tissue engineering nerve scaffold was investigated in vitro. The average diameter increased with decreasing the blend ratio of ApF to P(LLA-CL). Characterization of 13C NMR and FTIR clarified that there is no obvious chemical bond reaction between ApF and P(LLA-CL). The tensile strength and elongation at break increased with the content increase of P(LLA-CL). The surface hydrophilic property of nanofibrous scaffolds enhanced with the increased content of ApF. Cell viability studies with Schwann cells demonstrated that ApF/P(LLA-CL) blended nanofibrous scaffolds significantly promoted cell growth as compare to P(LLA-CL), especially when the weight ratio of ApF to P(LLA-CL) was 25:75. The present work provides a basis for further studies of this novel nanofibrous material (ApF/P(LLA-CL)) in peripheral nerve tissue repair or regeneration.
Figures and Tables |
References |
Related Articles |
Metrics
|
|
Preparation of porous hollow silica spheres via a layer-by-layer process and the chromatographic performance
Xiaobing WEI,Cairong GONG,Xujuan CHEN,Guoliang FAN,Xinhua XU
Front. Mater. Sci.. 2017, 11 (1): 33-41.
https://doi.org/10.1007/s11706-017-0366-z
Hollow silica spheres possessing excellent mechanical properties were successfully prepared through a layer-by-layer process using uniform polystyrene (PS) latex fabricated by dispersion polymerization as template. The formation of hollow SiO2 micro-spheres, structures and properties were observed in detail by zeta potential, SEM, TEM, FTIR, TGA and nitrogen sorption porosimetry. The results indicated that the hollow spheres were uniform with particle diameter of 1.6 μm and shell thickness of 150 nm. The surface area was 511 m2/g and the pore diameter was 8.36 nm. A new stationary phase for HPLC was obtained by using C18-derivatized hollow SiO2 micro-spheres as packing materials and the chromatographic properties were evaluated for the separation of some regular small molecules. The packed column showed low column pressure, high values of efficiency (up to about 43 000 plates/m) and appropriate asymmetry factors.
Figures and Tables |
References |
Related Articles |
Metrics
|
|
Photoluminescence and electrical properties of Er3+-doped Na0.5Bi4.5Ti4O15--Bi4Ti3O12 inter-growth ferroelectrics ceramics
Yalin JIANG,Xiangping JIANG,Chao CHEN,Yunjing CHEN,Xingan JIANG,Na TU
Front. Mater. Sci.. 2017, 11 (1): 51-58.
https://doi.org/10.1007/s11706-017-0367-y
Upconversion (UC) and electrical properties of Na0.5Bi8.5−xErxTi7O27 (NBT–BIT–xEr, 0.00≤x≤0.25) ceramics were studied. Structural analysis revealed that a single inter-growth structured phase exists in all samples and the Er3+ ion substituting for Bi3+ at the A-site increases the orthorhombic distortion. Under the 980 nm laser excitation, two characteristic green emission bands and one red emission band were situated at 527, 548 and 670 nm, corresponding to the transitions 2H11/2 → 4I15/2, 4S3/2 → 4I15/2 and 4F9/2 → 4I15/2, respectively. The optimal photoluminescence (PL) were found in the NBT–BIT–0.20Er sample, and the emission color transforms from green to yellowish green. Temperature dependence of fluorescence intensity ratio (FIR) for NBT–BIT–0.20Er was measured ranging from 290 to 440 K and its maximum sensitivity was calculated to be about 0.0020 K−1 at 290 K. Dielectric measurements indicated that TC slightly increased simultaneously with the decrease of tanδ. Therefore, this ceramic has potential applications for high-temperature multifunctional devices.
Figures and Tables |
References |
Related Articles |
Metrics
|
|
Isolation of fucoxanthin from Sargassum thunbergii and preparation of microcapsules based on palm stearin solid lipid core
Xuanxuan WANG,Hongyan LI,Fangqin WANG,Guixue XIA,Hongjun LIU,Xiaojie CHENG,Ming KONG,Ya LIU,Chao FENG,Xiguang CHEN,Ying WANG
Front. Mater. Sci.. 2017, 11 (1): 66-74.
https://doi.org/10.1007/s11706-017-0372-1
The objective of this study was to isolate fucoxanthin from Sargassum thunbergii and develop microcapsules with palm stearin as the solid lipid core for stability and efficient oral delivery of fucoxanthin. The microcapsules had smooth surfaces with the volume weighted mean diameter (d4.3) of 19.19 µm. Encapsulation efficiency and loading capacity of microcapsules with fucoxanthin were 98.3% and 0.04%, respectively. Moreover, the fucoxanthin in microcapsules presented higher stability than free fucoxanthin against light, humidity and temperature. Especially, the retention rates of fucoxanthin encapsulated in microcapsules reached 97.20% at 4°C, 92.60% at 25°C, 92.32% with the relative humidity of 33% and 92.60% in the dark. The cumulative amount of fucoxanthin released from microcapsules was 22.92% in simulated gastric fluid (SGF) and 56.55% in simulated intestinal fluid (SIF).
Figures and Tables |
References |
Related Articles |
Metrics
|
|
Enhanced micro-vibration sensitive high-damping capacity and mechanical strength achieved in Al matrix composites reinforced with garnet-like lithium electrolyte
Xian-Ping WANG,Yi ZHANG,Yu XIA,Wei-Bing JIANG,Hui LIU,Wang LIU,Yun-Xia GAO,Tao ZHANG,Qian-Feng FANG
Front. Mater. Sci.. 2017, 11 (1): 75-81.
https://doi.org/10.1007/s11706-017-0363-2
A novel micro-vibration sensitive-type high-damping Al matrix composites reinforced with Li7−xLa3Zr2−xNbxO12 (LLZNO, x = 0.25) was designed and prepared using an advanced spark plasma sintering (SPS) technique. The damping capacity and mechanical properties of LLZNO/Al composites (LLZNO content: 0–40 wt.%) were found to be greatly improved by the LLZNO addition. The maximum damping capacity and the ultimate tensile strength (UTS) of LLZNO/Al composite can be respectively up to 0.033 and 101.2 MPa in the case of 20 wt.% LLZNO addition. The enhancement of damping and mechanical properties of the composites was ascribed to the intrinsic high-damping capacity and strengthening effects of hard LLZNO particulate. This investigation provides a new insight to sensitively suppress micro-vibration of payloads in the aerospace environment.
Figures and Tables |
References |
Related Articles |
Metrics
|
10 articles
|