Water Uptake Capability Research Articles

In-situ manipulation of gel layer fouling into gel layer membrane formation on porous supports for water treatment

The inaccessibility of clean water is one of the growing issues of this era. Indeed, cost-effective and sustainable methods for recycling wastewater are essential. Although membrane separation is an efficient technology for the recycling and purification of water, membrane fouling is still a major drawback of this technology. This work is aimed to develop a dynamic method to form gel layer membranes (GLMs) by manipulating the irreversible fouling process itself as a problem-solving approach. A microporous polyvinylidene fluoride (PVDF) support is subjected to gel layer formation by applying a supernatant of industrial aerobic sludge (containing soluble extracellular polymeric substances EPS) as a feed. Retention of polysaccharides and calcium during the filtration and the topographical analysis after the filtration show that EPS uniformly formed a gel layer on the PVDF support. No further decline in permeability is observed (i.e. remained around 27–33 L/m 2 hr) when the formed GLM is subjected to fouling under similar conditions. Moreover, the percent flux recovery ratio (FRR) of the GLM is also significant (i.e. 90.1 ± 2.71). The retention ability, hydrophilicity, porosity, and water uptake capability of the formed GLM also increased significantly. The optimal performance and stability of GLMs are observed at room temperature (RT) under neutral pH and sub-critical trance membrane pressures (TMP). Based on these results it is suggested that the in-situ manipulation of gel layer fouling is a viable approach for preparing fouling resistant GLMs with high retention efficiency, potentially applicable to wastewater treatment under normal conditions.

Fabrication of a multilayered SGO/macroporous Nafion-based IPMC with enhanced actuation performance

Ionic polymer-metal composites (IPMCs) composed of Nafion film and platinum deposited on both faces have gained much attention in biomedical engineering as actuators because it can show large bending motion under an electric field. This study focuses on the design of a multilayered IPMC actuator based on sulfonated graphene oxide (SGO) modified macroporous Nafion film. The Nafion film is firstly fabricated via templating technique by using silica spheres as template and SGO as a conductive agent dispersed in Nafion film. Then, Pt nanoparticles are deposited on both faces of the as-prepared Nafion film to fabricate the actuator (denoted as IPMC-SGO-M). In the IPMC-SGO-M, macropores and SGO co-exist in the Nafion film, which can effectively enhance the rapid transport of ions and electrons. In addition, small Pt nanoparticles are uniformly dispersed on the surface of the Nafion film, which can improve the water-uptake capability and charge redistribution between two layers of electrode regions. As a result, the tip displacements of the IPMC-SGO-M are 1.7-fold and 1.9-fold higher than that of the IPMC based on macroporous Nafion film (IPMC-M) under 6.2 and 6.6 V, respectively. The blocking forces of the IPMC-SGO-M are about 2.6-fold and 2.3-fold higher than that of IPMC-M under 6.2 and 6.6 V, respectively.

Electrochemical performance of poly(arylene piperidinium) membranes and ionomers in anion exchange membrane fuel cells

Awakening interest in anion exchange membrane fuel cells (AEMFC) for low temperature applications has led to an increased demand for high-performing polymers stable under alkaline conditions. In this study a poly(p-terphenylene piperidinium)-based membrane and ionomer was synthesized and applied in membrane electrode assemblies (MEAs), with porous gas-diffusion electrodes based on Pt catalysts supported by VULCAN® and high surface area carbon, respectively. The MEAs were evaluated in AEMFC single-cell tests. In order to identify specific beneficial characteristics of the polymer, the results were compared to reference tests using a commercial Aemion™-polymer. Steady-state polarisation performance measurements were carried out as well as electrode characterisations via cyclic voltammetry and electrochemical impedance spectroscopy, in addition to ex-situ characterisation of the polymer and the membrane electrode assemblies. Poly(p-terphenylene piperidinium)-based (PAP) membranes showed great potential with an in-situ measured average ohmic resistance of 0.09 Ωcm2. Mass transport limitations at higher current densities were observed for high surface area carbon electrodes, leading to an overall higher performance with the use of VULCAN®. Properties of the ionomer related to water uptake capabilities were observed to inhibit performance as well. The higher water uptake of PAP-based ionomers appears to be a key property for increasing electrode performance.

Hydrothermal ageing of hydrophobic nano-calcium carbonate/epoxy nanocomposites

In this study, we investigated the effects of the filler content and ageing temperature on the water absorption and tensile properties of hydrophobic nano-calcium carbonate (NCC)/epoxy nanocomposites. The NCC content of the nanocomposites was varied from 0 to 5 wt%, while the ageing temperature was set at 28, 45, and 55°C in a distilled water bath. The nanocomposites exhibited the non-Fickian behaviour at all the NCC contents and ageing temperatures. In general, the water absorption of the nanocomposites increased after the addition of NCC. Meanwhile, the diffusivity of the nanocomposites decreased with an increase in the NCC content; however, this decrease became less significant at higher ageing temperatures. Although the addition of 1–3 wt% NCC significantly increased the water uptake capability of the nanocomposites, it resulted in an improvement in their tensile properties at high temperatures and prolonged ageing times.

Composition Optimization of Triple Conducting PrNixCo1-XO3-δ Oxygen Electrodes for Protonic Ceramic Electrochemical Cells

Using protonic ceramic electrochemical cells (PCECs) to produce hydrogen is a promising approach to achieve the renewable energy storage, and development of critical materials is the key step to facilitate fast hydrogen production rate. Particularly, the sluggish electrode kinetic at reduced temperatures (400~600 °C) and chemical stability under realistic high steam concentration raises concern. We have recently reported a triple conducting oxide of PrNi0.5Co0.5O3-δ perovskite as an oxygen electrode in PCECs, which exhibits superior electrochemical performance in both fuel cell and electrolysis modes, and potential increased stability due to the absence of alkaline elements such as Ba and Sr in the composition. In this work, the continuous composition optimization of PrNixCo1-xO3-δ (x=0.1, 0.3, 0.5, 0.7, and 0.9) oxides is carried out to find the dependence of Ni/Co ratio on the catalytic activity towards oxygen reduction and water splitting reactions. The isotope water temperature-programmed desorption and thermogravimetric analysis is used to study the water uptake capability for understanding the proton concentration variation as function of doping level. The Fourier-transform infrared spectroscopy (FTIR) is also utilized to observe relative intensity change of the hydroxyl band on electrode surface to further explain the possible species evolution in the relevant reaction modes. This work provides a representative approach on composition optimization for oxygen electrode candidate down selection.

Design and characterization of highly porous curcumin loaded freeze-dried wafers for wound healing

The goal of this research was to evaluate the beneficial effects of topical curcumin loaded freeze-dried wafers in wound healing. Curcumin wafers were fabricated by cross-linking of chitosan with beta glycerophosphate under magnetic stirring. Composite wafers were prepared by the addition of sodium hyaluronate. Wafers were fabricated by freeze-drying technique. The resulted wafers were examined by naked eye and their dimensions were measured using a caliper. % Drug content, in-vitro release and % water uptake tests were conducted to characterize the fabricated wafers. Porosity testing, compressive mechanical behavior, morphological examination using scanning electron microscopy, thermal behavior using differential scanning calorimetry and Fourier transform infrared spectroscopy were all carried out on the optimized cross-linked wafers followed by their microbiological assays and cytotoxicity studies. The results showed that the optimized wafers possessed high water uptake capabilities while entertaining very high porosity levels (86-89%). Microbiological assay revealed the superiority of the selected curcumin wafers versus free curcumin in bacterial growth inhibition against Staphylococcus epidermidis and Staphylococcus aureus (MRSA) bacteria. The anti-inflammatory effects of the selected curcumin wafers were evaluated against pro-inflammatory cytokines. The results suggested that they were significantly better than free curcumin in lowering cytokines levels. To conclude, the obtained findings revealed that curcumin wafers offered a promising solution in the field of wound healing.

Anion Exchange Membrane Based on Sulfonated Poly (Styrene-Ethylene-Butylene-Styrene) Copolymers.

Sulfonated poly(styrene-ethylene-butylene-styrene) copolymer (S-SEBS) was prepared as an anion exchange membrane using the casting method. The prepared S-SEBS was further modified with sulfonic acid groups and grafted with maleic anhydride (MA) to improve the ionic conducting properties. The prepared MA-grafted S-SEBS (S-SEBS-g-MA) membranes were characterized by Fourier transform infrared red (FT-IR) spectroscopy and dynamic modulus analysis (DMA). The morphology of the S-SEBS and S-SEBS-g-MA was investigated using atomic force microscopy (AFM) analysis. The modified membranes formed ionic channels by means of association with the sulfonate group and carboxyl group in the SEBS. The electrochemical properties of the modified SEBS membranes, such as water uptake capability, impedance spectroscopy, ionic conductivity, and ionic exchange capacity (IEC), were also measured. The electrochemical analysis revealed that the S-SEBS-g-MA anion exchange membrane showed ionic conductivity of 0.25 S/cm at 100% relative humidity, with 72.5% water uptake capacity. Interestingly, we did not observe any changes in their mechanical and chemical properties, which revealed the robustness of the modified SEBS membrane.

A compositionally synergistic approach for the development of a multifunctional bilayer scaffold with antibacterial property for infected and chronic wounds

The increased complexity of the healing process and interplay of various pathological factors in cutaneous wounds, in particular, chronic wounds, entails a meticulous and spatiotemporally sufficient treatment to accomplish successful therapy. Here, we have developed the hybrid bilayer scaffold system using cryogelation and electrospinning techniques to closely resemble the native three-dimensional architecture of skin. The bilayer scaffold involves curcumin dextran nanoparticles (CDNp) and cerium oxide nanoparticles (CeO2) loaded gelatin cryogel layer and polyvinyl alcohol-poly (vinyl pyrrolidone)-iodine-potassium iodide (PPI-KI) electrospun fibrous layer towards the outer side. The developed scaffold exhibited high water uptake capability, degradation and hemocompatibility besides showing sustained and prolonged release of CDNp (65% ± 2.61 in 120 h) and iodine (66.47% ± 2.073 in 72 h). The in-vitro studies of bilayer scaffold, cryogels and electrospun sheet demonstrated enhanced cell viability and accelerated cell migration apart from displaying a strong antioxidant and antibacterial activity. The developed scaffolds elucidated a faster-wound closure rate in the in-vivo wound model in comparison to commercially available dressing and other groups. Further, in the infected wound model, the bilayer scaffold prevented wound infection and showed rapid and efficient healing of wounds. The developed dressing was observed to promote mature epithelialization with ample hair growth and increased deposition of mature collagen. Thus, the novel synergistic approach can remarkably provide new insights for the design of advanced and multifunctional wound dressing with potential application in accelerating the healing of cutaneous wounds.

Preparation of biocompatible wound dressings with dual release of antibiotic and platelet-rich plasma for enhancing infected wound healing.

The ever-growing threats of bacterial infection and chronic wound healing have provoked an urgent need for novel antibacterial wound dressings. In this study, we developed a wound dressing for the treatment of infected wounds, which can reduce the inflammatory period (through the use of gentamycin sulfate (GS)) and enhance the granulation stage (through the addition of platelet-rich plasma (PRP)). Herein, the sustained antimicrobial CMC/GMs@GS/PRP wound dressings were developed by using gelatin microspheres (GMs) loading GS and PRP, covalent bonding to carboxymethyl chitosan (CMC). The prepared dressings exhibited high water uptake capability, appropriate porosity, excellent mechanical properties, sustain release of PRP and GS. Meanwhile, the wound dressing showed good biocompatibility and excellent antibacterial ability against Gram-negative and Gram-positive bacteria. Moreover, in vivo experiments further demonstrated that the prepared dressings could accelerate the healing process of E. coli and S. aureus-infected full-thickness wounds in vivo, reepithelialization, collagen deposition and angiogenesis. In addition, the treatment of CMC/GMs@GS/PRP wound dressing could reduce bacterial count, inhibit pro-inflammatory factors (TNF-α, IL-1β and IL-6), and enhance anti-inflammatory factors (TGF-β1). The findings of this study suggested that biocompatible wound dressings with dual release of GS and PRP have great potential in the treatment of chronic and infected wounds.

The environment temperature affects post-germination growth and root system architecture of pea (Pisum sativum L) plants

Seeds of ten different pea genotypes were sown in styrofoam transplant trays filled with vermiculite and kept in two different growth chambers, respectively at air temperatures of 10 °C and 15 °C. In both chambers the relative humidity was maintained at 90%, PPFD 180 μmol m−2 s−1and the photoperiod 12 h. At DAS 15 and 31, ten plant of each treatment were selected randomly, dissected and separated into roots and shoots. Root system was scanned and acquired root images were analyzed. Subsequently, all plant organs were dried (65 °C, 48 h) and weighed separately. Significant genetic variation was identified regarding root traits. Rather than with the drought resistance and N foraging capability the genetic variation was associated with P foraging capability of the root system. Despite significant genotype differences, root traits were remarkably affected by environment temperature. The suboptimum temperature reduced growth and delayed root development processes. The decrease of temperature from 15 °C to 10 °C was followed by a significant decrease in the dry matter of plant, but the ratio of root dry matter to plant dry matter was significantly increased. The total root length was also significantly decreased, almost totally due to a significant decrease in the lateral root length. Only slight effects were found regarding tap root length. Water and nutrient uptake capabilities of pea plants were enhanced under optimum temperature conditions, mostly due to increased lateral root density and extended root branching zone deeper into the soil. Either the differences in lateral root (LR) density or the length of branching zone seems to be related with the effects of temperature to the length of development time from LR initiation to LR emergence.

In-Vitro Study of Polysulfone-polyethylene glycol/chitosan (PEG-PSf/CS) Membranes for Urea and Creatinine Permeation

High concentrations of creatinine and urea in the blood can be removed by dialysis using semipermeable membranes that are selective for certain species and hold other species through diffusion processes. This ability requires a membrane that has an active side, which functions as a targeted species identifier. The membrane must be biocompatible because the membrane will be in direct contact with the body’s biological systems. The membrane material that is made must be acceptable to the blood system so that there is no rejection from the body and have a large contact area to obtain an effective diffusion process. For this reason, a hollow fiber membrane (HFM) is needed. One of the synthetic polymers used as the base material for HFM is PSf. PSf has mechanical strength, heat resistance, and is easily formed into HFM. However, PSf has disadvantages such as lack of active side and less compatible with blood due to its hydrophobic properties. Modification using PEG and chitosan will reduce the hydrophobicity of the PSf. Membrane results were analyzed the physical, chemical, and transportability for urea and creatinine. The results of functional group characterization by FTIR show that the modification reaction was successfully carried out on polysulfone to produce PEG-PSf/CS. The modification succeeded in making the PSf membrane more hydrophilic, as evidenced by a decrease in the contact angle from 69.4° (PSf) to 53° (PEG-PSf/CS). Water uptake capability increases to 609%, and membrane porosity increases porosity increased from 72 to 83%. The water flux is also increased. Creatinine clearance ability increases from 0.09 mg/dl to 0.25 mg/dL. Urea clearance ability increases from 2.3 mg/dL to 3.07 mg/dL. The SEM image showed that the modification makes the membranes more porous.

Preparation, characterization and antimicrobial activity of grafted cellulose fiber from durian rind waste

In this work, novel strategy for the low-cost and facile grafting copolymerization between isolated cellulose from durian rind waste (DRC) and 2-[acryloyloxyl] ethyltrimethylammonium chloride (CIAETA) initiated with potassium persulfate was developed. Subsequently, the grafting yield of 30.4 % was obtained. Comparative characterization of the ungrafted and grafted cellulose through techniques such as FTIR, SEM, XRD and thermogravimetry confirmed the grafting of the CIAETA monomers onto DRC polymer backbone (DRC-g-CIAETA). Grafting process resulting in formation of porosity of DRC and coarse structure, thus crystallinity index slightly reduced from 48.45 to 36.58 %, however DRC-g-CIAETA increased in thermal stability. Water uptake capability revealed a significant enhancement by almost three times due to the hydrophilicity of CIAETA monomer. In addition, DRC-g-CIAETA demonstrated excellent antibacterial and antifungal ability against S. aureus, S. epidermis, and C. albicans. These antimicrobial properties exhibited potential application in biomedical healthcare fields.

Microwave Treatments of Cereals: Effects on Thermophysical and Parenchymal-Related Properties.

Dielectric heating is one of the most interesting techniques for pest disinfestation. However, most of the literature works give information about the ability of microwave treatments at different power-time conditions to kill insects; less is given about the analysis of matrices structural properties and heat transport. Accordingly, the aim of this work is to investigate the effect of microwave treatments, applied for pest disinfestation, on heat transport behavior and physical/structural properties, such as water uptake capability, mineral losses, texture change, and germination capability, of most consumed cereals in human diet, such as weak wheat, durum wheat, and corn. Two different radiative treatments were performed: one in time-temperature conditions capable of inactivating the weed fauna, and the other at high temperatures of ~150 °C, simulating uncontrolled treatments. Heat transport properties were measured and showed to keep unvaried during both effective and uncontrolled microwave treatments. Instead, grain physical properties were worsened when exposed to high temperatures (reduction of germination ability and texture degradation). The achieved results, on the one hand, provide new structural and heat transport data of cereals after microwave treatments, actually not present in the literature, and on the other, they confirm the importance of correctly performing microwave treatments for an effective disinfestation without affecting matrices physical properties and nutritional features.

Electrospun Fibers and Sorbents as a Possible Basis for Effective Composite Wound Dressings.

Skin burns and ulcers are considered hard-to-heal wounds due to their high infection risk. For this reason, designing new options for wound dressings is a growing need. The objective of this work is to investigate the properties of poly (ε-caprolactone)/poly (vinyl-pyrrolidone) (PCL/PVP) microfibers produced via electrospinning along with sorbents loaded with Argovit™ silver nanoparticles (Ag-Si/Al2O3) as constituent components for composite wound dressings. The physicochemical properties of the fibers and sorbents were characterized using scanning electron microscopy (SEM), differential scanning calorimetry (DSC), Fourier transform infrared spectroscopy (FTIR) and inductively coupled plasma optical emission spectroscopy (ICP-OES). The mechanical properties of the fibers were also evaluated. The results of this work showed that the tested fibrous scaffolds have melting temperatures suitable for wound dressings design (58–60 °C). In addition, they demonstrated to be stable even after seven days in physiological solution, showing no macroscopic damage due to PVP release at the microscopic scale. Pelletized sorbents with the higher particle size demonstrated to have the best water uptake capabilities. Both, fibers and sorbents showed antimicrobial activity against Gram-negative bacteria Pseudomona aeruginosa and Escherichia coli, Gram-positive Staphylococcus aureus and the fungus Candida albicans. The best physicochemical properties were obtained with a scaffold produced with a PCL/PVP ratio of 85:15, this polymeric scaffold demonstrated the most antimicrobial activity without affecting the cell viability of human fibroblast. Pelletized Ag/Si-Al2O3-3 sorbent possessed the best water uptake capability and the higher antimicrobial activity, over time between all the sorbents tested. The combination of PCL/PVP 85:15 microfibers with the chosen Ag/Si-Al2O3-3 sorbent will be used in the following work for creation of wound dressings possessing exudate retention, biocompatibility and antimicrobial activity.

Strontium-substituted biphasic calcium phosphate scaffold for orthopedic applications

Strontium ion-substituted calcium phosphate-based ceramic scaffolds enhance osteogenesis. The objective of the present study was to optimize the strontium hydroxyapatite (Sr-HA) and beta tricalcium phosphate (β-TCP) ratio in the fabricated scaffolds to enhance their mechanical strength and bioactivity with controlled biodegradability. Porous polyurethane sponge scaffolds containing Sr-HA and β-TCP in varying concentration were developed by dipping 3D sponge pieces into a slurry containing 10% gelatin, proper concentration of biphasic calcium phosphate (BCP) and 3% poly vinyl alcohol. Four different samples [Sr-BCP, Sr-BCP (20/80), Sr-BCP (30/70), Sr-BCP (40/60)] were prepared and were characterized for biodegradability, water uptake capability and cytotoxicity using various techniques. Pure, crystalline, cytocompatible Sr-BCP Scaffolds possessing both micropores and macropores with porosity greater than 80% and water uptake capability above 100% were obtained. Thus, the effective substitution of Sr-HA and β-TCP in varying proportion makes the composite scaffold a distinctive material of bone tissue engineering.

Surface Functionalization of Wool via Microbial-Transglutaminase as Bio-Mordant to Improve Dyeability with Madder in the Presence of Alum

Herein, the wool fabric was mordanted with alum, treated with microbial transglutaminase (m-TGase), and then dyed with madder. Different concentrations of alum and m-TGase were used to find out the optimum condition to achieve the best color after dyeing the wool fabrics with aqueous extract of madder. FT-IR spectroscopy and scanning electron microscopy (SEM) methods were applied to characterize the as-prepared samples. Contact angle measurements showed that the water uptake capability was increased in the case of the wool sample treated with alum and enzyme. Moreover, the samples were assessed for color strength (K/S) and color fastness. Our results showed that the optimal condition to get the highest color value was for the sample with 10% owf (of weight of fabric) alum and 5% owf m-TGase. Furthermore, it was found that there was a critical concentration for enzyme so that an increase in m-TGase amount would cause damage to the scales of fibers. The best condition of the dyeing process was discussed in this study, and also the proposed mechanism was presented. Indeed, treatment of wool with m-TGase led to a reduction in the amount of consumed alum, while investigations in color performances demonstrated the enhancement in color fastness, as well as color strength.

On the preparation and physicochemical properties of pH-responsive hydrogel nanocomposite based on poly(acid methacrylic)/laponite RDS

In this paper, a series of novel poly(methacrylic acid)/laponite RDS (PMAA/Lap RDS) nanocomposite hydrogels crosslinked by N,N’-methylene bisacrylamide were synthesized via free radical polymerization by using potassium persulfate as initiator. The main novelty of this paper refers to the detail investigation of how the laponite RDS influenced of the pKa, and consequently, the water-uptake of these nanocomposites. In parallel, the evidence of incorporation and interactions of the materials was confirmed by scanning electron microscopy and Fourier transform infrared spectra techniques. By the X-ray diffraction technique (XRD), it was possible to confirm the exfoliation/intercalation configuration of the nanoclay laponite RDS (Lap RDS) into the PMAA matrix. Hydrophilic properties, measured by swelling degree (SD), indicated that the presence of Lap RDS influenced the water uptake capability of the nanocomposite, reaching a maximum of 91 ± 2 g/g for nanocomposites constituted by 5 % of nanoclay. Besides, the pKa of the nanocomposite can be adjusted by nanoclay content. In this way, the ability of these hydrogels to respond to pH values can be useful to act as trigger in controlled release systems.

A hydrogen sulfide-releasing alginate dressing for effective wound healing

For wounds with heavy exudate levels, a dressing that can help to absorb wound exudate and improve the wound healing process is highly desired. Hydrogen sulfide (H2S) has been recognized as an important gasotransmitter that can improve angiogenesis which is crucial for wound healing. In this study, a functional sodium alginate (SA) dressing with H2S-releasing property (SA/JK-1) was fabricated by incorporating JK-1 molecule, a pH-dependent H2S donor, into SA sponge. The resultant SA/JK-1 sponge provided a moist and protective healing environment and was capable of releasing H2S consistently under acidic pH condition by absorbing exudate at the wound interface. The H2S release of JK-1 donor was prolonged by the SA sponge compared with JK-1 in solution. Cell study in vitro indicated that SA/JK-1 not only exhibited good cyto-compatibility, but also improved fibroblast proliferation and migration. In addition, the effects of the SA/JK-1 dressing on wound healing was evaluated using an in vivo full thickness dermal defect model, which revealed that SA/JK-1 can significantly improve wound healing process with enhanced granulation tissue formation, re-epithelialization, collagen deposition and angiogenesis, due to the H2S released from JK-1. Taken together, our results showed that SA dressing doped with H2S donor could potentially serves as an effective wound healing strategy. Statement of significanceThe gasotransmitter H2S has been proven to improve the wound healing process in nanofibrous dressing due to its biological functions on angiogenesis. However, for non-healing wounds with heavy exudates, a wound dressing that can absorb wound exudates and controlled gasotransmitter release to improve the wound healing process is still in urgent need. Here we fabricated a sodium alginate (SA) sponge incorporated with H2S donor JK-1 (SA/JK-1), which showed strong water uptake capability, and released H2S under acidic condition. The SA/JK-1 sponge exhibited biocompatibility to fibroblasts and promoted cell migration in vitro, and exhibited obviously positive influence on wound healing in vivo. This H2S donor doped alginate wound dressing represents a promising strategy for treatment of non-healing wound.

Cytocompatible, thermostable hydrogel with utility to release drug over skin

Hydrogel has wide applicability in biomedical applications and other industrial applications due to its strong biocompatibility. A natural polymer is eco-friendly, nontoxic, and biocompatible. There are vast varieties of natural polymers whose combination can form excellent hydrogels. Pectin and carboxymethyl cellulose (CMC) are some such kinds of polymers. Plasticizer has wide applicability to enhance properties of polymers mix. Glycerol has been widely used as a plasticizer in many hydrogels but it does not render thermostability whereas, PEG is known to render thermostability. Thermostable hydrogel provides easy sterilization by using heat and pressure such as an autoclave. Small molecular size plasticizer is known to provide more space among the polymer mix and affect the porosity and water uptake capability. PEG 400 has wide applications in pharmaceutical industries and it is one of the small molecular size plasticizers. Other than this, copper ions are known to render skin regenerative property with biocidal property help in the wound healing treatment. Thus, a hydrogel was fabricated using pectin and CMC with PEG 400 as the plasticizer and copper ion as cross-linker (PCPEG2). The resulted hydrogel not only showed high thermal stability but also has high porosity, a high degree of swelling, pH sensitivity and good cytocompatibility and good drug release efficiency. The hydrogel was characterized by using FTIR, XRD, DSC, TGA/DTG/DTA, and XPS which showed good fabrication of hydrogel with high thermal stability. Thus, a novel hydrogel of pectin/CMC with PEG 400 was fabricated with enhancing properties applicable in biomedical applications and other industrial applications.

Characterization and actuation behavior of SPS/SGO ion exchange polymer actuator based on PEDOT: PSS/SGO composite electrode

ABSTRACTThis paper studied the fabrication of new hybrid-type poly(3,4- ethylene dioxythiophene) (PEDOT)/sulfonated graphene oxide electrode-based polymer actuator produced by film casting method. Sulfonated Poly(1,4-phenylene ether-ether sulfone) (SPS) ion-exchange polymer membrane-based ionic polymer composite actuators were fabricated using the different concentration of SGO. The characterization and actuation were demonstrated. By altering SGO concentration, four different SPS based membrane actuators were analyzed. The effects of SGO concentration on the morphology, proton conductivity, ion exchange capacity, and water uptake capability were studied. The maximum tip displacement and force by varying concentration of SGO were evaluated for the actuation performance.