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Nanofibrous filter media of polyamide-6/chitosan were fabricated by electrospinning onto a satin fabric substrate and characterized by scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), and water contact angle (WCA). Anionic dye removal capability of the filter was investigated for Solophenyl Red 3BL and Polar Yellow GN, respectively, as acidic and direct dyes were investigated with respect to solution parameters (pH and initial dye concentration) and membrane parameters (electrospinning time and chitosan ratio) through filtration system. Experiments were designed using response surface methodology (RSM) based on five-level central composite design (CCD) with four parameters to maximize removal efficiency of the filter media. Moreover, the effect of parameters and their likely interactions on dye removal were investigated by mathematically developed models. The optimum values for solution pH, initial dye concentration, electrospinning time, and chitosan ratio were predicted to be 5, 50 mg/L, 4 hr, 30% and 5, 100 mg/L, 4 hr, 10%, respectively, for achieving 96% and 95% removal of Solophenyl Red 3BL and Polar Yellow GN. Evaluation of the estimation capability of applied models revealed that the models have a good agreement with experimental values. This study demonstrated that polyamide-6/chitosan nanofibrous membrane has an enormous applicable potential in dye removal from aqueous solutions.

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In this study, the authors present a promising structure of shape-stabilized phase change materials (PCMs) with remarkable thermal energy storage capacity as core/shell phase change nanofibers. In this regard, solutions of polyethylene glycol (PEG) (as an important category of PCMs) and cellulose acetate (CA) were used as core and shell solutions, respectively. Electrospinning with a coaxial spinneret was performed, and nanofibers with the mean diameter of 545 nm under the controlled condition were produced. The formation of the core/shell structure was verified by scanning electron microscopy, attenuated total reflection Fourier transform infrared spectroscopy, and transmission electron microscopy analyses. Moreover, thermogravimetric analysis results not only revealed the thermal stability improvement of PCM but also confirmed the presence of the core/shell structure too. Differential scanning calorimetry analysis was also performed to measure the thermal energy storage capacity of the core/shell phase change nanofibers before and after a thermal cyclic test. A major finding in the present study is that the thermal energy storage capacity of core/shell nanofibers after the thermal cyclic test is significantly higher (41.23 J/g) than initial one (14.77 J/g). Ultimately, it can be summarized that the special core/shell configuration provides desirable thermal stability and durability concurrently along with high thermal energy storage capacity. C 2015 Wiley Periodicals, Inc. Adv Polym Technol 2016, 35, 21534; View this article online at wileyonlinelibrary.com.

In this study, fabrication, characterization, and adsorption properties of alginate (Alg)-based nanofibrous membrane were investigated for two categories of anionic (AR14) and cationic (BB41) dyes. Three optimization steps were performed to achieve the membrane enjoying desirable morphology, highest Alg content, and lowest possible nanofiber diameter. Consequently, Alg/poly(ethylene oxide) nanofibers with the 80:20 ratio and mean diameter of 93 nm were produced. A novel method was applied as spraying the cross-linking solution to diminish the solubility of the nanofibers in aqueous environments. The effect of solution pH, contact time, membrane dosage, and dye concentration on the adsorption performance was evaluated. The results showed that the produced membrane has an obvious pH dependency in which the maximum adsorption capacity at the solution pH of 1 and 9 were 93% and 71% for AR14 and BB41, respectively. The present work revealed that the Alg-based nanofibrous membranes have a great potential to remove both anionic and cationic dyes from aqueous solutions. C 2015 Wiley Periodicals, Inc. Adv Polym Technol 2016, , 21569; View this article online at wileyonlinelibrary.com.

The main aim of the present study is to fabricate a high performance chitosan (CS)/polyvinyl alcohol (PVA) electrospun nanofibrous mat having a high content of CS, a desirable morphology (defect‐free structure) and a superfine diameter (approx. 100 nm). As electrospinning of constructions containing CS is known as a complex process, it is necessary to employ systematic control and optimisation of processes. In this regard, the controlling and optimisation of the processes were followed by two subsequent stages. In the first stage, morphology controlling parameters were investigated with respect to CS/PVA solution characteristics including CS concentration, solvent concentration and the content of the partner polymer (PVA). In the second stage, in order to attain the finest possible diameter, process modelling was carried out in terms of processing parameters (applied voltage, nozzle‐collector distance and feed rate) by using response surface methodology (RSM). According to the experimental results of the first stage, the best morphological structure containing the highest content of CS was obtained under 3% (w/v) of CS, concentrated acetic acid (90%) and 20% weight ratio of PVA. The significance of the applied model was confirmed by statistical approaches and the effect of the selected parameters on the diameter was studied. Experimentally, the finest diameter of 104 ± 18 nm was obtained under optimised processing parameters determined from the RSM technique. The experimental value of the nanofibre diameter was in close agreement with the predicted value in which the prediction error of the model was only 1.92% confirming the high reliability of the applied model.

A photo-responsive molecule-gated drug delivery system (DDS) based on silicone-hydrogel (poly(HEMA-co-PEGMEA)) interpenetrating polymer networks (IPN) functionalized with carboxylated spiropyran (SPCOOH) was designed and demonstrated as an on-demand DDS. The triggered release mechanism relies on controlling the wetting behaviour of the surface by light, exploiting different hydrophobicity between the "closed" and "open" isomers of spiropyran as the photo-switchable molecular gate on the surface of IPN (SP-photogated IPN). The light-triggered release of doxycycline (DOX) as the model drug indicated that the spiropyran (SP) molecules provide a hydrophobic layer around the drug carrier and have a good gate-closing efficiency for IPNs with 20-30 % hydrogel content. Upon UV light irradiation the SP convert to the open hydrophilic merocyanine state, which triggers the release of DOX. These results were compared with a previously developed SP-bulk modified IPN using the same hydrogel as a control, proving the efficiency of the gated IPN system. The covalent attachment of SPCOOH to the alcohol groups of the hydrogel and the structural change caused by UV light was indicated with FTIR analysis. XPS results also confirms the presence of SP by indicating the atomic percentage of nitrogen with respect to the hydrogel content.

Waste cooking oils are problematic disposal especially in the developed countries. In this paper, waste cooking oil is used as raw material to produce foam. The purpose of the study is to develop the high density solid biopolymer (HDB) by using hot compression moulding technique based on flexible and rigid crosslinking agents. Physical properties such as Scanning Electron Microscope (SEM) and density of HDB were examined. The acoustic study of HDB for flexible and rigid has been measured using impedance tube test according ASTM E1050 standard with multiple layers of thicknesses. It was revealed that higher thicknesses of HDB exhibit less sound absorption coefficients. This situation is occurred for both flexible and rigid HDB. The frequency also shifted to the left when the layers of HDB were increased for both materials. The highest increment was 63.46%, observed from two layers from flexible and rigid HDB. For the conclusion, rigid HDB showed that they could absorb more sound, thus having higher noise reduction coefficient (NRC) than flexible HDB at low frequency.