Obtaining medical textiles including microcapsules of the ozonated vegetable oils

In this paper, it was aimed to obtain disposable medical textiles having antibacterial and wound healing properties, as well as biological adaption. For this purpose, the St. John’s Wort oil and flax seed oil were ozonated, and the oils were capsulated with arabic gum. The produced ozonated oils were characterized through FTIR and TGA analyses, as well as the properties of antibacterial, wound healing, and biological adaption were investigated. The produced microcapsules were examined via optical microscope and FTIR. The characterized microcapsules of the ozonated oils were applied to the textiles with padding method. After the applications, the fabrics were researched with SEM and FTIR analyses; in addition the antibacterial and wound healing properties and biological adaption of the textiles were also investigated. The results showed that the St. John’s Wort oil and flax seed oil were successfully ozonated and microcapsulated. The microcapsules of the oils could be applied to the fabric samples with the determined application recipe. The ozonated oils and the fabric samples applied microcapsules of the ozonated oils gained high antibacterial and wound healing property. In addition, the fabric samples were produced as having biological adaptation.     

Preparation and performance as PEM of sulfonated pre-oxidized nanofiber/SPEEK composite membrane

Building proton transfer channel is an important strategy to optimize the proton transfer process of the proton exchange membrane (PEM). In this work, sulfonated pre-oxidized nanofibers were prepared by solution blowing of polyacrylonitrile (PAN) nanofibers followed by pre-oxidization and sulfonating, and the nanofibers were composited with SPEEK to enhance its performance as PEM. The results of the proton conductivity verified that the employment of sulfonated pre-oxidized nanofibers improved the proton conductivity. Meanwhile, the introduction of the sulfonated pre-oxidized nanofibers realized the upgrades of the thermostability and water absorbency of the membrane, and led to the decrease of the swelling property and methyl alcohol’s permeability of the material. It is indicated that the composite membrane is promising materials for PEM fuel cells.     

Electroneutral cornstarch by quaternization and sulfosuccinylation to improve the adhesion of cold starch paste to raw cotton for low-temperature sizing

The objective of this research was to survey the effects of starch quaternization and sulfosuccinylation on the adhesion of cold starch paste to raw cotton fibers for cotton warp sizing at low temperature. Acid-thinned cornstarch (ATS) was quaternized and then sulfosuccinylated to introduce 3-(trimethylammonium chloride)-2-hydroxypropyl and sulfosuccinate substituents onto its backbones. The electroneutrality of starch samples prepared was achieved by maintaining a constant mole ratio (5.3:1) of the two substituents. A series of electroneutral cornstarch (ECS) samples with different levels of the substituents were derived by altering the feed ratio of the modifying reagents to starch for determining desirable level of starch modification. Adverse influences of cotton wax and starch retrogradation on the adhesion of cold starch paste to raw cotton fibers were evaluated to illustrate the effectiveness of starch quaternization and sulfosuccinylation. It was found that the modification was able to alleviate the adverse influence of starch retrogradation and ameliorate the adhesion to the fibers at low temperature. Higher level of the modification led to less retrogradation and resulted in strong adhesion. Furthermore, the adverse influence of cotton wax on the adhesion could be eliminated after a pre-wetting treatment of raw cotton warps with hot water. The adhesion of ECS paste to raw cotton at 60 °C was statically the same as that of ATS at 95 °C when total DS of ECS was 0.0443 or higher.     

Preparation and characterizations of polypyrrole on liquid ammonia pre-treated wool fabric

Wool fabric was treated with liquid ammonia at -40 °C for 30 and 60 s prior to the application of polypyrrole (PPy). The polymer was deposited on wool fiber using the chemical oxidation method with 0.02 and 0.05 mol/l (Py) monomer concentration and FeCl₃ as a catalyst. Functional groups of wool samples were analyzed using FT-IR, and surface morphology was investigated using SEM micrographs. Properties such as water absorbency, surface resistivity, abrasion resistance, weight add-on, and air permeability of coated specimens were explored. The FT-IR outcomes revealed the liquid ammonia pre-treatment changed the amount of amide I (NH), cystic acid, cystic monoxide, and dioxide content of the fiber. SEM micrographs revealed the descaling of wool surface after pre-treatment and smooth coating of polymer. Pre-treatment of wool in liquid ammonia improved absorbency of wool fabric with respect to the treatment duration. The surface resistivity of wool fabric decreased with the increase of monomer concentration and pre-treatment duration. The results of abrasion resistance confirmed that the pre-treated fabric exhibited lower loss of polymer after 200 cycles of abrasion. The weight of the fabric was increased and air permeability decreased when the monomer concentration and liquid ammonia pre-treatment duration was increased.     

Chemical synthesis of polypyrrole film and its adsorption capacity for aromatic polycarboxylic acids

Polypyrrole (PPy) film was prepared via in-situ chemical polymerization of pyrrole monomer on the surface of red-clay-brick (RCB) substrate. The deposited PPy film was characterized and used as an adsorbent for removal of benzene polycarboxylic acids from aqueous solutions. The effects of solution pH, contact time, initial concentration, and temperature on the adsorption process were systematically investigated to find the optimum operating conditions. Adsorption kinetic data were best fitted by pseudo-second order kinetic model. The adsorption equilibrium data were most represented by the Freundlich isotherm model. The maximum adsorption amounts of Trimellitic, Hemimellitic, and Pyromellitic acids were 189.27, 177.26, and 203.31 mg/g, respectively. The thermodynamic studies indicate that the adsorption was an endothermic and spontaneous process. Also, the PPy-RCB film was successfully regenerated using sodium hydroxide solution. The regenerated PPy-RCB can be reused for more than four successive cycles with a low reduction in adsorption efficiency.     

Influence of synergism caused by organic montmorillonite and nanometer calcium carbonate on mechanical properties and crystallization of polyamide 1010-based composites

This account showed that nanometer-active calcium carbonate (CaCO₃) improved polyamide 1010/organic montmorillonite (OMMT) composites and OMMT boosted polyamide 1010/CaCO₃. The mechanical performance suggested the composites to be reinforced through adsorption forces present between the nanofillers and the matrix. The synergistic effect of CaCO₃ and OMMT increased the yields and shrunk cavities when observed by scanning electron microscopy. The obvious resulting synergism was verified by X-ray scattering techniques after the addition of OMMT. The concentration of CaCO₃ did not change lamellar-size or influence the crystal growth. The effect of CaCO₃ on melting behavior was found less significant than that exert on crystallization behavior.     

Effects of date palm leaf fiber on the thermal and tensile properties of recycled ternary polyolefin blend composites

This work investigated the effects of date palm leaf fiber (DPLF) content on the thermal and tensile properties; and morphology of compatibilized polyolefin ternary blend. Recycled polyolefin ternary blend consisting of low density polyethylene (RLDPE), high density polyethylene (RHDPE) and polypropylene (RPP) were fabricated at different parts per hundred resin (phr) of DPLF. Maleic anhydride grafted polyethylene (MAPE) was used as compatibilizer to enhance the adhesion between filler and polymer matrix. The composites were prepared using melt extrusion and tests samples were produced via injection molding process. Thermal conductivity results showed that as much as 11 % reduction in thermal conductivity was achieved with the incorporation of 30 phr DPLF. Highest tensile strength was observed with the incorporation of 10 phr DPLF. The elongation at break was reduced with the addition of DPLF due to impediment of chain mobility by the fillers. Initial degradation temperature increased with the addition of DPLF. Hence, it is concluded that DPLF can be used to develop green and thermally insulating composites. It is hoped that the present results will stimulate further studies on the thermally insulative materials based on natural fibers reinforced polymer composites for applications in the building industries.     

Characterization of the surface properties of cellulosic fibers in fibrous and ground forms by IGC and contact angle measurements

Surface properties of fibrous and ground cotton and linen were investigated by inverse gas chromatography (IGC) and the contact angle with different liquids was also measured on fabrics composed of both fibers. Results proved that dispersion component of surface tension (γ _s ^d ) determined by IGC depends not only on the surface energy, but also on several factors influencing the adsorbability of probe molecules on the cellulosic substrates. For cotton samples, the trapping of n-alkanes among waxy molecules in the outer layer of fibers can be presumed. This effect results in larger γ _s ^d for cotton fibers than for linen in spite of the higher wettability of the linen fabrics. Besides the surface energy and trapping effects, the grinding also influences the γ _s ^d values. Specific enthalpy of adsorption (ΔH _A ^ab ) of polar probes could be determined on all linen samples, but only on the ground cotton sample. Lewis acid-base character calculated for linen and ground cotton samples depends on the same effects as the γ _s ^d does. The similar ΔH _A ^ab values of chloroform (acidic) and THF (basic) measured on each of the samples support the conclusion that the surface character is amphoteric, which is also proved by the high ΔH _A ^ab values of the amphoteric ethyl acetate and acetone probes.     

Polyvinylidene fluoride nanofiber coated polypropylene nonwoven fabric as a membrane for lithium-ion batteries

Polyvinylidene fluoride (PVdF) membranes in spite of having many critical properties necessary for lithium-ion batteries, do not have satisfying thermal and mechanical resistance. The goal of this study was to combine the good mechanical and thermal properties of PP nonwoven fabric with the excellent electrochemical properties of PVdF nanofibers to exploit a high-performance membrane for lithium-ion batteries. This work reports the preparation of PVdF nanofiber membranes using electrospinning on a polypropylene (PP) spunbonded nonwoven fabric and an aluminum foil followed by a hot-pressing treatment. The morphology and size of the membranes were studied by the scanning electron microscopy. The tensile strength of the membrane with the PP support was superior to the PVdF membrane. Thermal stability of the prepared membranes was determined using the TGA method and the dimensional stability was investigated by measuring the shrinkage ratio at 105 °C. The results have shown that the PVdF/PP membrane was thermally more stable than the PVdF and the commercial Celgard 2325 membranes. The batteries using PVdF/PP membrane exhibited higher electrochemical oxidation limit, better cycling performance and less discharge capacity fading during 100 cycles compared to PVdF and Celgard membranes. The results of this study showed that PVdF/PP membrane is a promising advanced membrane in lithium-ion batteries.     

Preparation and properties of solid polymer electrolyte based on imidazolium-based ionic liquids for structural capacitors

We prepared solid polymer electrolytes (SPEs) composed of poly(ethylene glycol) monomethyl ether acrylate (1A9OMe) and 1-ethyl-3-methylimidazolium trifluoromethanesulfonate ([EMIm][OTF]) and 1-ethyl-3-methylimidazolium bis(trifluoromethane sulfonyl) imide ([EMIm][TFSI]) as the ionic liquid. The SPEs formed by appropriately adding ionic liquids in the 1A9OMe prior to thermal cure. The ratio of 1A9OMe and ionic liquid was 1:9, 3:7, and 5:5, respectively. The characterization of solid polymer electrolytes were investigated using Fourier transform infrared spectroscopy in the attenuated total reflectance mode (FTIR-ATR), Electrochemical impedance spectroscopy (EIS), cyclic voltammetry (CV), and glavanostatic charge-discharge test. The highest ionic conductivity of SPEs was found to be 4.90×10^?4 S/cm in a 1A9OMe/[EMIm][OTF] of 3:7. As IL contents were increased, the specific capacitance of supercapacitor was increased. The specific capacitance of supercapacitor for ionic liquid with large ion size was lower than that for ionic liquid with smaller ion size.