Co-reporter:Chuang Liu, Zhongyi Jiang, Zhenwei Tong, Yixiao Li and Dong Yang
RSC Advances 2014 vol. 4(Issue 1) pp:434-441
Publication Date(Web):06 Nov 2013
DOI:10.1039/C3RA44630A
Inspired by the synthetic biology and biomineralization mechanism, a de novo designed biomimetic strategy is developed for the synthesis of metal oxide–metal nanocomposites (NCs) in aqueous solution under ambient conditions in this study. Via the screening of amino acids, it is found that arginine (R) can induce the formation of TiO2 and SiO2 nanoparticles (NPs), while tyrosine (Y) can reduce Ag+ and Au3+ ions into Ag and Au NPs, respectively. Subsequently, an artificial bifunctional peptide, arginine4tyrosine2 (R4Y2), as an example of this strategy, is designed to synthesize inorganic NCs including TiO2–Ag, TiO2–Au and SiO2–Ag, in which the positively charged moiety (R4) accelerates the polycondensation of negatively charged Ti or Si precursors, and the phenolic hydroxyl moiety (Y2) reduces Ag+ or Au3+ ions. This strategy may open an avenue for the green and controllable fabrication of a broad spectrum of inorganic NCs using artificial peptides as the inducer, designed rationally through encoding different parts of functional amino acids.
Co-reporter:G. Liu;Z. Jiang;Y. Wang ;D. Yang
Chemical Engineering & Technology 2013 Volume 36( Issue 2) pp:332-338
Publication Date(Web):
DOI:10.1002/ceat.201200353
Abstract
A new kind of hollow titania spheres-chitosan (hTiO2-CS) hybrid membranes was prepared by a physical blending method. hTiO2 spheres were found to disperse well in the as-prepared hTiO2-CS hybrid membranes. Their incorporation can reduce the chitosan crystallinity and enhance slightly its hydrophilicity and thermal stability. Subsequently, hTiO2-CS/PAN composite membranes comprising of the hTiO2-CS hybrid membrane as separation layer and a polyacrylonitrile (PAN) membrane as support layer were fabricated. Compared to the CS/PAN membrane, all of them exhibit a much better flux and separation factor for a 90 wt % aqueous solution of isopropanol at 80 °C. This promising kind of composite membranes may find potential application in the dehydration of alcohols.
Co-reporter:Yuanyuan Zhu, Zhongyi Jiang, Lei Zhang, Jiafu Shi, and Dong Yang
Industrial & Engineering Chemistry Research 2012 Volume 51(Issue 1) pp:255-261
Publication Date(Web):November 22, 2011
DOI:10.1021/ie2015069
Boehmite particles were prepared by a facile sol–gel method using sodium aluminate as the precursor under ambient conditions, and they were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), powder X-ray diffraction (XRD), nitrogen adsorption, etc. It is found that the boehmite particles consist of flat nanostrips, which are about 230 nm in length and 30 nm in width. The nanostrips are composed of nanoneedles of about 7 nm in diameter and 24 nm in length. The Brunauer–Emmett–Teller (BET) specific surface area, pore size, and pore volume of boehmite particles are 165 m2 g–1, 3.8 nm, and 0.11 cm3 g–1, respectively. Moreover, these boehmite particles are used as an efficient and robust carrier to encapsulate a model enzyme: bovine liver catalase. The catalase encapsulated in boehmite particles exhibits higher pH, thermal, and storage stabilities compared to its free counterpart. These results indicate that boehmite may become a competitive carrier for biological and technological applications.
Co-reporter:Lichao Cao, Ying Shi, Jiaqing Geng, Dong Yang
Materials Chemistry and Physics 2011 130(3) pp: 1280-1286
Publication Date(Web):
DOI:10.1016/j.matchemphys.2011.09.015
Co-reporter:J. Geng;Z. Jiang;J. Wang;Y. Shi;D. Yang ;L. Xiao
Chemical Engineering & Technology 2010 Volume 33( Issue 2) pp:244-250
Publication Date(Web):
DOI:10.1002/ceat.200900443
Abstract
Titanate nanotubes (TNTs) about 10 nm in diameter and 200–600 nm in length were hydrothermally synthesized, and then incorporated into a chitosan (CS) matrix to fabricate chitosan/titanate nanotube (CS/TNT) hybrid membranes for a direct methanol fuel cell (DMFC). These hybrid membranes were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray powder diffraction (XRD), thermogravimetry (TG), and positron annihilation lifetime spectroscopy (PALS). Moreover, their performances, including mechanical strength, water and methanol uptake, methanol permeability, and proton conductivity were determined. SEM results demonstrated that TNTs dispersed homogeneously in the hybrid membranes. Mechanical strength and TG measurements demonstrated that the mechanical and thermal stability of CS/TNT hybrid membranes were much higher than those of pure chitosan membranes. PALS analysis revealed that the fractional free volume (FFV) of CS/TNT hybrid membranes increased with the incorporation of TNTs and, thus, resulting in the reduction of methanol crossover. In all as-prepared membranes, the hybrid membrane containing 15 wt % TNTs exhibited the highest mechanical strength of 85.0 MPa, low methanol permeability of 0.497 · 10–6 cm2·s–1, and proton conductivity of 0.0151 S·cm–1, which had the potential for DMFC applications.
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