Anhydrous proton conductor consisting of pectin–inorganic composite material

An organic–inorganic proton conductive composite material consisting of a biopolymer was prepared by mixing the pectin, tetraethyl titanate, and imidazole. Although the pectin material without the composite dissolved in water, the pectin–inorganic composite material did not show water solubility. In addition, in the composite material, the pectin and imidazole formed an acid–base structure by an electrostatic interaction, and as a result, these composite materials showed a thermal stability at intermediate temperatures (100–200°C). Furthermore, these composite materials indicated the proton conductivity of 5.6 × 10^?4 S cm^?1 at 180°C under anhydrous conditions. The activation energy of the proton conduction under anhydrous conditions was 0.32–0.22 eV and these values were one order of magnitude higher than that of the typical humidified perfluorinated membrane, such as Nafion^®. The organic–inorganic composite material consisting of a biocomponent may have the potential to be utilized as a novel proton conductor under anhydrous conditions. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 42433.     

Preparation of aerochitin‐TiO2 composite for efficient photocatalytic degradation of methylene blue

An aerochitin–titania (TiO₂) composite was successfully synthesized and characterized by Fourier transform infrared spectroscopy, X‐ray diffraction, thermogravimetric analysis, field emission scanning electron microscopy, and N₂ adsorption isotherms. The photocatalytic activity of the composite was investigated on the degradation of the model organic pollutant, methylene blue (MB) dye, under UV irradiation. The aerochitin–TiO₂ composite showed excellent adsorptive and photocatalytic activity with a degradation degree of 98% for MB. The first‐order rate constants for the photodegradation MB by TiO₂ nanoparticles and aerochitin–TiO₂ composite were found to be (3.49 ± 0.04) × 10^?3 and (1.82 ± 0.02) × 10^?2 min^?1. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 45908.     

Theophylline‐loaded pectin‐based hydrogels. I. Effect of medium pH and preparation conditions on drug release profile

In this study, a series of theophylline‐loaded calcium pectin gel films were prepared in three different Ca⁺² concentrations with three different methods for wound dressing applications. Drug release performance of the films were investigated in four different medium pH in order to mimic wound healing pH conditions. Hydrogel films were characterized by Fourier transform infrared spectroscopy, differential scanning calorimetry, scanning electron microscopy and atomic force microscopy. Their absorbency (fluid handling), swelling behavior, dehydration rate, dispersion characteristic, dressing pH determination, water vapor permeability, oxygen permeability, surface contact angle, flexibility, Shore A hardness, mean mass per unit area and thickness were determined. The effect of the hydrogels on wound healing was evaluated with an in vitro wound healing assay. After evaluating all data, we suggested that the hydrogel film prepared with swelling method using 7% or 10% crosslinker and dried at 26 °C is more suitable for controlled drug release process. We showed that between pH 3.25 and 7.12 the form of the hydrogel did not change, and drug release was continuous. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 46731.     

Preparation of chitosan and carboxymethylcellulose-based polyelectrolyte complex hydrogel via SD-A-SGT method and its adsorption of anionic and cationic dye

The excellent properties of the polyelectrolyte complex hydrogels (PECHs) prepared with polysaccharides only, including polyampholyte, low toxicity, green, and clean production, have endowed them great application potentials as the adsorbents for dye-containing wastewater treatments. In the current study, the PECH of chitosan (CTS) and carboxymethylcellulose (CMC) was prepared by semi-dissolution acidification sol–gel transition (SD-A-SGT) method. The hydrogel was formed by the strong electrostatic interaction of cationic  NH₃⁺ groups of CTS and the anionic  COO⁻ groups of CMC. This simple but efficient means exhibited great potentials in constructing PECHs with uniform composition and controllable sol–gel transitions. Molecular dynamics simulation was first employed to predict the formation process and the microstructure of PECHs prepared by SD-A-SGT method. The structure and properties of the CTS-CMC PECHs were also characterized by Fourier transform infrared spectroscopy, SS ¹³C-NMR, scanning electron microscopy, mechanical tests, and rheological measurements, respectively. Taking the advantage of amphoteric polyelectrolyte properties, adsorption properties of anionic and cationic dyes were investigated using sunset yellow FCF and methylene blue as model dyes, respectively. The PECHs prepared in the present work had good adsorption capacity for both cationic and anionic dyes with maximum adsorption capacity of 212.83 mg/g for sunset yellow FCF and 167.35 mg/g for methylene blue. Therefore, this PECH would be a promising environmentally friendly adsorbent for the treatment of functional molecules with different charges.     

Preparation,characterization and antioxidant activity of acetylated garlic polysaccharide,and garlic polysaccharide-Zn (II) complex

Garlic polysaccharide (PS) was extracted from garlic by hot-water extraction. Acetylated garlic polysaccharide (AcPS) and garlic polysaccharide-zinc complex (ZnPS) were synthesized. The results of Fourier transform infrared spectroscopy and nuclear magnetic resonance spectroscopy analysis showed that the modifications were successful. The antioxidant activities of PS, AcPS, and ZnPS were further investigated in vitro, including scavenging superoxide anion and hydroxyl radicals, antilipid peroxidation capacity, and reducing power. The results showed that the scavenging abilities of AcPS and ZnPS on hydroxyl radical (The IC₅₀ of PS, AcPS, and ZnPS were 2.86, 1.62 and, 1.49 mg/ml, respectively,) and superoxide anion radical (The scavenging rate of PS, AcPS, and ZnPS were 1.5% and 1.8%, and 2.3%, respectively, when concentration was at 1.0 mg/ml.) were stronger than that of PS, and the inhibitory effect of AcPS on lipid peroxidation was significantly stronger than that of PS (The IC₅₀ of PS and AcPS were 1.05 and 0.53 mg/ml, respectively.). It indicated that the acetylation was a favorable way to enhance the antioxidant activity of garlic PS; ZnPS complex could be applied as potential candidate for antioxidant and Zn supplement.     

Preparation and application of magnetic chitosan in environmental remediation and other fields: A review

Magnetic chitosan has received considerable attention over the decades due to its low cost, biodegradability, green sources, magnetic intensity. In this review, we reviewed the preparation methods of magnetic chitosan using co-precipitation, cross-linking and electrochemical. Therein cross-linking methodologies involved in the reaction of amino groups are facile to introduce additional reaction groups and improve anti-swelling of chitosan layers, mostly in an acidic environment. Besides, we focused on the applications of magnetic chitosan in various fields such as wastewater treatment, for example, removal of heavy metal ions, organic/inorganic dyes, fluorides, and pesticides. Moreover, magnetic chitosan also reveals great potential application in the field of medical, pharmaceutical, food and electronic screening. Above all, magnetic chitosan is economically and operationally beneficial as it can be easily separated and controlled with an external magnetic field and can be modified to maximize its functions.     

Tunable wettability and tensile strength of chitosan membranes using keratin microparticles as reinforcement

Keratin particles with microscale are prepared by ball mill and its influences on the chitosan membrane is evaluated. Composite membranes with various content of keratin are fabricated, and their physical and chemical properties such as morphology, wettability, crystallization, thermal stability, tensile strength, and break elongation are investigated. Optical microscope and situ topographic scan mode of nano‐test system are used to examine the dispersion and aggregation of keratin on the surface of chitosan membrane. The result of contact angle (CA) and mechanical testing show that the incorporation of keratin particles decrease the CA from 98.1° to 58.2°. Tensile strength and break elongation of the composite membrane reaches a maximum of 65 ± 8 MPa and 15% when the keratin content is 6%, an increase of 80% and 88% compared with the pristine chitosan membrane. Both the increase in tensile strength and break elongation is result of the incorporation of keratin particles known for their excellent compatibility between keratin and chitosan matrix. These kind of composite material combines the antibacterial properties of chitosan with cell culture preference of keratin which may have potential biomedical application. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 44667.     

One‐step facile process to obtain insoluble polysaccharides fibrous mats from electrospinning of water‐soluble PMDA/cyclodextrin polymer

Herein, we used an electrospinning process to develop nanofibers based on poly‐cyclodextrin. This article describes a simple and effective method to produce fibers of a water‐soluble hyperbranched polymer based on β‐CD and pyromellitic dianhydride via electrospinning. The obtained fibers were made insoluble in water with a simple thermal crosslinking without the use of further reactive or solvent. After 24 h of dipping in distilled water or phosphate buffer solution morphology and size of fibers remain unaltered as observed in scanning electron microscopy. The crosslinking mechanism was studied with thermogravimetric analysis, attenuated total reflectance–Fourier infrared spectroscopy, and elemental analysis and a reaction mechanism is proposed. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 46490.     

Preparation of O‐hydroxypropyl‐N‐butyl chitosan under microwave irradiation

O‐Hydroxypropyl‐N‐butyl chitosan (C₄‐HPCS) was prepared by microwave irradiation and phase‐transfer catalysis; this consisted of two steps: (1) the synthesis of O‐hydroxypropyl chitosan (HPCS) with chitosan and propylene oxide and (2) the synthesis of C₄‐HPCS with HPCS and 1‐butyl bromide. The results of the experiment are as follows: Fourier transform infrared spectroscopy and ¹H‐NMR displayed the characteristic peaks of C₄‐HPCS, thermogravimetric analysis showed that C₄‐HPCS was stable until 240°C, the critical micelle concentration was 0.025 wt %, the surface tension was equal to 65.70 ± 0.09 mN/m, the hydrophile–lipophile balance number value was 13.55, and the emulsifying power, foaming expansion, and foaming volume stability were 73.10, 45, and 94 wt %, respectively. This indicated that C₄‐HPCS had superior surface performance and more excellent hydrophilicity. In addition, the microwave irradiation and phase‐transfer catalysis used in the experiment were considered to be more environmentally friendly and time‐saving methods. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 41527.     

Utilization of ramon seeds (Brosimum alicastrum swarts) as a new source material for thermoplastic starch production

The development and characterization of biodegradable polymers deriving from renewable natural sources has attracted much attention. The aim of this work was to partially characterize a thermoplastic starch obtained from the starch of seeds from the ramon tree (TPS‐RS) as an option to substitute thermoplastic starch from corn (TPS‐CS), in some of its applications. At 55% of relative humidity (RH), TPS‐RS had higher tensile strength and deformation than TPS‐CS. X‐ray diffraction analysis showed similar values in residual crystallinity (percentage of crystallinity that remains after plasticization process) in both TPS. The SEM micrographs showed a few remnant granular structures in the TPS‐RS. The FTIR showed a greater intensity in band at 1016 cm^?1 in the TPS‐CS and TPS‐RS in comparison with their corresponding native starch, indicating an increase in the amorphous region after plasticization. The TGA analysis showed greater thermal stability in TPS‐CS (340 °C) compared with TPS‐RS (327 °C). In addition, the glass transition temperature in both TPS was 24 °C. The results obtained represent a starting point to potentialize the use of TPS‐RS instead of TPS‐CS for the development of new biodegradable materials for practical applications in different areas. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 44235.     

Simultaneous removal of Cd,Co, Cu,Mn, Ni,and Zn from synthetic solutions on a hemp-based felt. III. Real discharge waters

Two hemp-based materials were used as nonconventional adsorbents for the final treatment of industrial discharge waters (DWs) from a metal-finishing plant. The first adsorbent, referred as HEMP, was a felt made of 100% hemp fiber. The second was the same felt coated with a maltodextrin-1,2,3,4-butanetetracarboxylic crosslinked polymer (HEMPM) in order to provide ion-exchange properties to the material by introducing carboxylic groups. The batch experiments showed that both materials exhibited high adsorption capacities toward metal ions present in 12 DWs, leading to concentrations well below those allowed by the French regulation. Measurements of the germination rate of Lactuca sativa seeds and of mobility inhibition of Daphnia magna, used as ecotoxicological tests, were carried out on DWs before and after hemp treatment. The average germination rate before and after treatment were 47.2 ± 4.1 for untreated DWs, 71.2 ± 6.3 for DWs treated by HEMP, and 89.3 ± 4.7 for DWs treated by HEMPM. The EC50 values for four DWs were between 2.1 and 10.4% of DW, indicating high toxicity. After HEMPM treatment, exposure to the DW for 24 h did not cause immobilization (EC50 > 90%). © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020 , 137, 48823.     

Preparation and evaluation of composite microspheres of polyacrylamide‐grafted polysaccharides

The poor mechanical strength and instability of polysaccharide's gel takes away opportunities for versatile application. The grafting of polyacrylamide (PAM) onto polysaccharide was found to be an efficient tool for transforming its properties and obtaining stable and robust composite microspheres (CMs). In this study, free‐radical polymerization reaction was used for the grafting of PAM onto the polysaccharide backbone, and their hydrogel CMs were obtained through an ionotropic gelation method. Porous and buoyant CMs were obtained through the incorporation of sodium bicarbonate into the reaction mixture. Characterizations were done through Fourier transform infrared spectroscopy, thermal and scanning electron microscopy analysis. The mechanical strength and squeezing capacity were evaluated extensively through a modified syringe method developed in‐house. The squeezing capacity of grafted CMs diminished with the formation of a complex interpenetrating network. The Young's modulus, swelling kinetics, mechanical strength, and squeezing capacity of the grafted microspheres were compared extensively. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 130: 2912–2922, 2013     

Studies on chain extension of a novel bio‐based engineering elastomer using 4,4‐diphenyl methane diisocyanate as a chain extender

A novel hydroxyl‐terminated bio‐based engineering elastomer (BEE) was synthesized from four bio‐based monomers by adding excess diol. Then the BEE was chain extended in Haake torque rheometer with 4,4‐diphenyl methane diisocyanate (MDI) as chain extender. The molar ratio of NCO/OH, reaction temperature and reaction time of the chain‐extension reaction were studied, and the optimum condition was determined by the gel permeation chromatography (GPC), soxhlet extraction, and fourier transform infrared spectroscopy (FTIR) results. After chain extension, (i) the number‐average molecular weight of BEE became about 3.5 times of the original BEE, (ii) the thermal stability was improved and the crystallization rate was lower, (iii) and the mechanical properties were significantly improved with nano‐SiO₂ as reinforcing filler. The chain‐extended BEE would have potential wide applications in engineering field. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40756.     

Preparation,characterization, and release behavior of ceftiofur‐loaded gelatin‐based microspheres

Drug‐loaded microspheres prepared from biomacromolecules have received considerable interest. In this article, we report a facile method for preparing ceftiofur‐loaded gelatin‐based microspheres for controlled release. We investigated the effects of factors, including the rotational speed, concentration of surfactant, concentration of gelatin, and ratio of water to oil (W/O), on the morphologies of gelatin microspheres and obtained the optimized conditions; for a typical average diameter of about 15 μm, these were 1000 rpm, a concentration of span 80 of 2.0%, a gelatin concentration of 20%, and a W/O of 1:20. Gelatin microspheres loaded with ceftiofur, ceftiofur‐Na, and ceftiofur‐HCl were prepared and characterized by scanning electron microscopy and laser light scattering. In vitro release studies were carefully performed for microspheres prepared with different crosslinker contents, loaded with different drugs, and blended with chitosan. The loaded ceftiofur showed an obviously longer release time compared with pure ceftiofur powder. A higher content of crosslinker led to a longer release time, but when the content reached 5%, the microspheres had a significantly cracked surface. The results also indicate that the blending of a small amount of chitosan could greatly prolong the release time. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 130: 2369–2376, 2013     

Fabrication of starch‐g‐poly(l‐lactic acid) biocomposite films: Effects of the shear‐mixing and reactive‐extrusion conditions

In this study, we developed a new approach for the fabrication of a green poly(l ‐lactic acid)‐grafted starch (St‐g‐PLA) copolymer and nanocomposite (St‐g‐PLA/organoclay)‐based films via shear‐mixing and reactive‐extrusion systems. The chemical and physical structures, thermal behavior, and morphology of the synthesized blends and some other parameters were examined by Fourier transform infrared spectroscopy and ¹³C cross‐polarization/magic angle spinning NMR spectroscopy, X‐ray diffraction, thermogravimetric analysis–derivative thermogravimetry, and scanning electron microscopy, respectively. Significant increases in the mechanical and permeability properties were evident in the high value of grafted poly(lactic acid) molar percentages and high exfoliation of organoclay. The biodegradability of films were investigated under aerobic composting conditions through the measurement of the temperature, moisture, pH, consumed O₂ value, and carbon dioxide produced. This new strategy mainly improved the good adhesion between both phases, and it was an interesting method for the production of environmentally friendly biocomposites that could easily be scaled up for commercial production with the potential for replacing petroleum‐based plastics. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 44490.     

The synthesis of modified alginate flocculants and their properties for removing heavy metal ions of wastewater

A new flocculant was synthesized through the modification of sodium alginate with thiosemicarbazide. In the preparation, amino thiourea groups which had excellent adsorption properties for heavy metal ions were introduced to the flocculant. The structure of the flocculant was confirmed by elemental analysis, Fourier transform infrared, UV spectrophotometry, nuclear magnetic resonance, and thermal analysis. The flocculation behaviors of the flocculant for three heavy metal ions were investigated. The results showed that the removal rates of the flocculant for Pb²⁺, Cd²⁺, and Cu²⁺ reached up to 97.8%, 86.3%, and 80.0%, respectively, and the flocculation capacities were as high as 489, 215, and 160 mg/g, respectively. The excellent adsorption was ascribed to the double effects of electronic interaction and chelation between the flocculant and heavy metal ions. The flocculant had particular flocculation selectivity for Pb²⁺ in the mixed heavy metal ion solutions containing Cd²⁺or Cu²⁺, respectively. The flocculation process corresponded to Langmuir isotherm model, the flocculation kinetics agree with pseudo second order. The flocculant had potential applications for treatment of wastewater. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 46577.     

Hydroxypropylmethyl cellulose‐based sponges loaded self‐microemulsifying curcumin: Preparation,characterization, and in vivo oral absorption studies

Novel hydroxypropylmethyl cellulose (HPMC)‐based sponges containing self‐microemulsifying curcumin (SME‐Cur) were prepared by a freeze drying method using different grades of HPMC (E5 LV, E15 LV, E50 LV, A15 LV, and A4C). The physical properties and drug release from these carriers were characterized and compared among the different formulations. The mean pore size values of the sponges from image analysis ranged from 43.36 ± 4.54 to 123.22 ± 8.19 nm. An increase in the concentration or viscosity of the HPMC, resulted in denser sponges and a slower drug release. The average microemulsion droplet size from the optimal sponge formulation was 34.80 ± 0.1 nm, and the curcumin was almost completely released within 120 min. The AUC after oral administration of the liquid and solid SME‐Cur were 7‐ and 5‐fold greater than that of the curcumin powder in the rabbit, respectively. The results demonstrated that the HPMC‐based sponges loaded with SME‐Cur could be efficiently used to enhance the oral bioavailability and might be useful as they could be administered at a lower dose compared to normal curcumin powder. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 42966.     

Physicochemical properties and antimicrobial activity of biocompatible carboxymethylcellulose‐silver nanoparticle hybrids for wound dressing and epidermal repair

Skin loss can be caused by accident, burn, trauma, chronic wounds, and diseases, which is severely aggravated by multidrug‐resistant bacterial infections. Soft hybrids based on biopolymers combined with silver nanoparticles (AgNPs) have potential applications as wound dressing supports and skin tissue repair. Thus, our study focused on the design, green synthesis, and comprehensive characterization of carboxymethyl cellulose (CMC–AgNP) nanocomposites for producing hydrogel membranes, with tunable physicochemical properties, cytocompatibility, and biocidal activity for potential application as wound dressing and skin repair. These nanocomposites were prepared using CMC with two degrees of carboxymethylation, distinct concentrations of citric acid (CA) crosslinker, and AgNPs by in situ chemical reduction, forming hybrid membranes by the solvent casting method. The results demonstrated that superabsorbent hydrogels were produced with swelling and degradation behaviors dependent on the concentration of CA crosslinker, degree of carboxymethylation of CMC, and content of AgNP in the matrices. Moreover, the Fourier transform infrared spectroscopy analysis evidenced that the CMC functional groups (e.g., ? COOH and ? OH) were directly involved in the chemical reactions for the formation of AgNPs and hydrogel crosslinking pathway. These nanocomposites were cytocompatible using in vitro 3‐(4,5‐dimethyl‐2‐thiazolyl)‐2,5‐diphenyltetrazolium bromide cell viability assay with of human embryonic kidney cells. Conclusively, the CMC–AgNP nanohybrids demonstrated to be simultaneously non‐toxic combined with highly effective antibacterial activity against gram‐positive multi‐resistant wound/skin pathogens (Staphylococcus aureus) and moderate effect towards gram‐negative strains (Escherichia coli and Pseudomonas aeruginosa). © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 45812.     

Oil‐spill cleanup: The influence of acetylated curaua fibers on the oil‐removal capability of magnetic composites

A magnetic resin based on cardanol, furfural, and curaua fibers was prepared and characterized. The material could be used in oil‐spill cleanup processes, because of its aromatic/aliphatic balance. The resin was prepared through bulk polycondensation of cardanol and furfural in the presence of curaua fibers and maghemite nanoparticles. Hydrophobicity of the curaua fibers was improved by acetylation, increasing the oil‐absorbing capability of the composites. The obtained magnetic composites were studied by Fourier‐transform infrared spectroscopy, X‐ray diffraction, and thermogravimetric analysis. Degree of cure, magnetic force, and oil‐removal capability tests were also performed. The results show that the composites possess an elevated cure degree in addition to a considerable magnetic force. The materials exhibit a good oil removal capability in the presence of a magnetic field, which is improved by the use of acetylated curaua. In the best case, the composite filled with maghemite and curaua can remove 12 parts of oil from water. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 41732.     

Seaweed‐ZnO composite for better antibacterial properties

Brown seaweed Padina tetrastromatica (PTS)‐Zinc oxide (ZnO) composites were prepared by chemical precipitation method. The characteristic peaks of PTS and ZnO were confirmed by Fourier transform infrared spectroscopy. X‐ray diffraction study was confirmed the formation of ZnO with hexagonal wurtzite phase. Surface morphology and particle's distribution of ZnO were characterized by scanning electron microscopy. Transmission Electron microscopy image reveals that ZnO nanorods are in the size range of 14–164 nm having uniformly blended with polysaccharide of seaweed. Ultraviolet‐Visible absorption spectra indicated the sharp absorption peak at 219 nm and broad absorption peak in the 250–350 nm range. Fluorescence spectra shows the broad blue‐violet emissions is around at 380–480 nm. Because of the interaction between polysaccharide and ZnO nanorods/particles, the prepared seaweed‐ZnO composite exhibit better antibacterial activity than pure ZnO nanoparticles. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40948.