Xin Jin

Effect of vapor-phase glutaraldehyde crosslinking on electrospun starch fibers

In this work, we have proven that starch nanofibrous membranes with high tensile strength, water stability and non-cytotoxicity can be produced by electrospinning of starch solution and post-treatment with GTA in vapor phase. GTA vapor phase crosslinking plays a key role in forming water-stable nanofiber membrane and improving the mechanical properties. Comparing with non-crosslinked starch fibers, the crosslinked fibers are increased by nearly 10 times in tensile strength. The crosslinked starch fibrous membranes are non-cytotoxic. They may find applications in the fields of tissue engineering, pharmaceutical therapy and medical.

Study of preparation conditions of novel dissolving coating method applied to PA6 fibres

Abstract In the dissolving coating method, dissolution of the fibre surface is the necessary condition for imparting durability conductivity to fibre. On the other hand, it would make a strong effect on the mechanical properties of the treated fibre. The main propose of the present paper is making a study on the preparing conditions of dissolving coating method both from the view of electrical and mechanical properties of final fibres. In the present research, there are four parameters associated with the electrical and mechanical properties of final fibres, i.e. concentration of solvent A, content of CB in coating mixture B, dissolved PA6 polymer content in coating mixture C and roller speed D. The influence of the main parameters on the mechanical and conductive properties was discussed using single factor tests first. Then, two orthogonal arrays were designed, and the optimisation dissolving coating method condition for PA6 fibres was confirmed.

Synthesis of Starch Acetates and Electrospinning

Acetylation of high amylose (50%) maize starch to high degree of substitution (DS) was synthesised by reacting starch with acetic anhydride using sodium hydroxide as the catalyst. Starch Acetate was dissolved in Dimethyl Sulphoxide (DMSO), the DS of which ranged from 0.8 to 1.8. Ultrafine fibers were made by the method of electrospinning. FTIR, NMR and SEM were used to characterize the structure and surface morphology of the product.

Preparation and Electrospinning of Acidified-Oxidized Potato Starch

This paper investigates the preparation and electrospinning of acidified-oxidized potato starch. In this article, acidified-oxidized potato starch was prepared by adding ammonium persulfate as an oxidizing agent and hydrochloric acid as a catalyst. The effect of reaction time, temperature, the concentration of hydrochloric acid and the content of ammonium persulfate on the viscosity and content of carboxyl were discussed. The optimum reaction conditions were as follows: 1.5 hours ,50°C, 0.5mol/l HCl, 2.5% (NH4)2S2O8. And then, the acidified-oxidized potato starch prepared at the optimum condition was dissolved in dimethyl sulfoxide (DMSO) to be electrospinned by contrast to native starch. Electrospinning of 5wt%-21wt% of modified starch in DMSO produced beads, beaded fibers, and smooth fibers, depending on the concentration range. Smooth fibers were observed until the concentration reached 19wt%, while native starch was 5wt%.

Effects of Oxygen-Plasma Treatment Time on the Properties of UHMWPE Fiber

Ultra-high-molecular-weight polyethylene (UHMWPE) fibers were treated by low temperature oxygen-plasma. The effects of oxygen-plasma treatment time on the properties of UHMWPE have been investigated. The wetting ability and roughness were increased significantly after the treatment. While, the tensile strength at break of UHMWE fibers were decreased with the treatment time. The optimum plasma treatment time is 2min.

Electrospinning preparation of a large surface area, hierarchically porous, and interconnected carbon nanofibrous network using polysulfone as a sacrificial polymer for high performance supercapacitors

Carbon nanofibrous mats (CNFMs) are prepared by electrospinning of blended precursor of polyacrylonitrile and polysulfone (PSF) followed by pre-oxidation stabilization and carbonization. Addition of PSF as a sacrificial polymer leads to CNFMs with high surface area, large numbers of micropores and mesopores, good degree of carbonization, and interconnected fibrous network, due to the high decomposition temperature, release of SO2 during decomposition, and large amount of carbon residue of PSF during carbonization. The electrochemical characterization shows that the CNFM electrode has a specific capacitance of 272 F g−1 at a current density of 1 A g−1 with 74% of the specific capacitance retained at 50 A g−1 in 2.0 M KOH electrolyte. The CNFM electrodes have excellent cycling durability with 100% capacitance retention after 10u2006000 cycles.

Highly Hydrophobic Conductive Polyester Fabric Based on Homogeneous Coating Surface Treatment

ABSTRACT A highly hydrophobic conductive polyester (PET-HE) fabric was prepared by a simple two-steps method. Firstly, homogeneous coating (the mixture of PET and carbon black (CB)) was uniformly coated on the PET fabric, which through curing in water coagulation bath and electrically conductive (PET-E) fabric was prepared. Then the solvent-induced crystallization process was adopted to PET-E fabric to endow the hydrophobic property. Investigations showed that PET-HE treated fabrics exhibited better hydrophobic and conductivity when the content of PET is 9wt% and the content of CB is the range of 8wt%-10wt%. The prepared polyester fabric proved to have such features as WCA was about 145°and surface resistance was about 300 Ω.GRAPHICAL ABSTRACT Graphical Abstract

One-Way Water Transport Fabrics Based on Roughness Gradient Structure with No Low Surface Energy Substances

Despite great recent progress in one-way water transport (OWT) fabrics, the development of these fabrics based on roughness gradient without low surface energy materials has yet to be achieved. In this work, we prepared OWT fabrics using five polymers with hydrophobic or hydrophilic groups by constructing a roughness gradient structure along the fabric thickness. Electrospraying was used to deposit a rough layer on fabrics single side. The surface energy gradient change across the fabric thickness derived from roughness gradient structure played a major part in determining the OWT performance. With the roughness gradient structure, even polymers with hydrophilic groups, such as polyacrylonitrile and polyamide 6, could become OWT fabrics. Besides, the layer deposited on the surface of the fabric showed no effects on the air permeability of the fabric. These novel results provided an opportunity for more polymers, especially for hydrophilic polymers, to be used to prepare OWT fabrics by designing a roughness gradient along the thickness of the fabric. The method would be applied in designing of OWT fabrics with high performance.

Surface Properties of UHMWPE Fiber after Low Temperature Argon-Plasma Treatment

To improve the adhesion between ultra-high-molecular-weight polyethylene (UHMWPE) fibers and matrix, the UHMWPE fibers were treated by low temperature argon-plasma. The effects of argon-plasma treatment on the properties of UHMWPE have been investigated. The roughness and wetting ability were all found to increase significantly after modifications. The tensile strength of UHMWE fibers were decreased with the plasma treatment time. The optimum plasma treatment is 2min.The increasing of roughness and wetting ability of UHMWPE fiber are beneficial to the improvement the adhesion between UHMWPE fiber and matrix.

Effect of Deposition Polymerization Technique of Pyrrole on Properties of UHMWPE Fiber

The two deposition polymerization techniques, i.e. vapor phase and liquid phase pyrrole deposition polymerization were applied to Ultra-high-molecular-weight polyethylene (UHMWPE) fiber in this paper. The effect of deposition technique on the surface morphology, mechanical properties, electrical stability and surface roughness of fibers were discussed. The result showed that deposition technique has a strong effect on the properties of UHMWPE fibers. Fibers treated by vapor phase deposition polymerization has much fine and small granular structure, lower resistance, better mechanical property and higher surface roughness value.