Synthesis,characterization, and redox and electrochromic behaviors of poly(3-n-octyloxythiophene)

Poly(3-n-octyloxythiophene), a conjugated polymer, which possessed solubility in common organic solvents, was synthesized by electrochemical polymerization in the presence of lithium perchlorate as the supporting electrolyte and sodium dodecyl sulfate as the surfactant in an aqueous medium. Characterizations of the intermediate, monomer, and polymer were performed by NMR spectroscopy, Fourier transform infrared spectroscopy, ultraviolet–visible spectroscopy, and gel permeation chromatography. The process of electrochemical polymerization and the electrochemical redox behaviors were investigated by cyclic voltammetry and the potentiostatic method. A poly(3-n-octyloxythiophene) film that was deposited on a platinum electrode was found to exhibit electrochromic behaviors, and it switched electrochemically between blue–green oxidized and dark red reduced states. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

Effects and properties of poly(arylene ether benzonitrile)s of various molecular weights blended with sulfonated poly(ether ether ketone)

Poly(arylene ether benzonitrile) (PAEBN) was synthesized with 2,6‐dichlorobenzonitrile and biphenol. PAEBNs with various molecular weights (MWs), 1,640,000 and 185,000 g/mol, were synthesized by control of the stoichiometry of the monomers and were blended with sulfonated poly(ether ether ketone) (SPEEK). The effects of MW on the water uptake, swelling, methanol permeability, and proton conductivity of the SPEEK/PAEBN blend membranes were investigated. The molecular mobility of the SPEEK/PAEBN blends was also examined in this study. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

Effect of Li+ ions on structure,properties, and actuation of cellulose electro‐active paper actuator

We have reported an electro‐active paper actuator from regenerated cellulose. After dissolving cellulose fibers with a solution of lithium chloride in N,N‐dimethylacetamide, cellulose was regenerated by combining distillation of cellulose solution along with washing with the mixture of deionized water, isopropyl alcohol, and running water. However, the effect of Li⁺ ions on structure, properties, and the actuation behavior of the actuator was not studied. This article describes the changes in these parameters when the Li⁺ ions are removed by subjecting it to different running water exposure time. The structure and properties of cellulose electro‐active paper and its actuation behavior were studied. As Li⁺ ions content reduced from 4354.17 to 10.26 ppm by increasing the exposure time of running water, crystallinity, Young's modulus, and bending displacement decreased. Details about the investigation have been explained. This elimination of ions is important to increase the piezoelectric effect in EAPap by decreasing the ion migration effect. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci 2008     

导向剂加入方式对Y型沸石合成的影响

以煤系高岭土为原料,采用液态补硅手段调节体系SiO2/Al2O3、导向剂两步加入法合成了Y型沸石.考察了导向剂不同加入方式对Y型沸石合成的影响.采用合理的导向剂两步加入法,特别是通过控制导向剂第二步加入的时间,可明显缩短Y型沸石的晶化时间,并有效地减少P型沸石的生成.     

Electrospinning of collagen-chitosan complex

The collagen-chitosan complex nanofibers have been prepared for the first time by electrospinning. The mixed HFP/TFA (the volume ratio of 90/10) was found to be the appropriate solvent for electrospinning. The concentration of the spinning solution and the ratio of chitosan/collagen were varied and adjusted to get smooth nanofibers. It was found that the diameter of the spun fibers became thick with the concentration of the solution increasing and became fine with the ratio of the chitosan/collagen increasing. We have characterised the molecular interactions in collagen-chitosan complex by Fourier transform infrared spectroscopy. The spun fibers are designed to mimic the native extracellular matrix for tissue engineering and to develop functional biomaterials.     

Preparation and Characterization of Carboxymethyl Chitosan and β-Cyclodextrin Microspheres by Spray Drying

Three kinds of carboxymethyl chitosan/β-cyclodextrin microspheres loaded with theophylline were prepared by spray drying intended for pulmonary delivery. Mucociliotoxicity, permeation rate, and drug release characteristics of the product were investigated. The microspheres obtained by spray drying were found to be spherical with smooth or wrinkled surfaces. The mean particle size was between 3.39 and 6.06 µm. The microspheres demonstrated high product yield (43.7-50.2%), high drug loading (13.7-38.1%), and high encapsulation efficiency (86.9-92.8%). FT-IR indicated that there were interactions of theophylline with carboxymethyl chitosan matrix. Further studies on mucociliotoxicity and permeation confirmed that microspheres had better adaptability and high permeation rate. In vitro drug release from the microspheres was not related to the drug/polymer ratios.     

The deposition morphology of Brownian/non-Brownian particles within a constricted tube

The deposition morphology of Brownian/non-Brownian particles within a constricted tube is investigated by applying the Brownian dynamics simulation method in the present paper. Two different geometric structures, the parabolic constricted tube (PCT) and the sinusoidal constricted tube (SCT), are adopted. The effect of various types of the total interaction energy curves of the Derjaguin-Landau-Verwey-Overbeek (DLVO) theory, and of the shadow area cast by those deposited particles, on the particles’ collection efficiencies are also examined. For the PCT structure, under the same interaction energy curve, it is found that the non-Brownian particles always own a higher collection efficiency than that of the Brownian particles. Since the deposition location moves closer to the constriction part of the tube, the collection efficiencies of the Brownian/non-Brownian particles increase with the decrease of flow velocity. The SCT behaves differently, it is found that the collection efficiencies of non-Brownian particles are only slightly higher than those of Brownian particles when SCT is adopted. The steep slope of the tube wall near the constriction part of SCT dominates the whole deposition process of Brownian/non-Brownian particles. In comparison with the available experimental data, it is found that the present method can give a good simulation result.