Crystallization kinetics,morphology, and hydrolytic degradation of novel bio‐based poly(lactic acid)/crystalline silk nano‐discs nanobiocomposites

In this work, novel biodegradable crystalline silk nano‐discs (CSNs) having a disc‐like morphology have been utilized for fabrication of poly(lactic acid) (PLA) nanocomposites by melt‐extrusion. The main focus is to investigate the effect of CSN on isothermal melt crystallization kinetics, spherulitic growth rates, morphology, and hydrolytic degradation of PLA. Spherulitic morphology and growth rates are examined over a wide range of crystallization temperatures (90–120 °C). With incorporation of CSN, the isothermal crystallization kinetics of PLA/CSN increases, however, the crystallization mechanism remains unaltered. The apparent activation energy and surface energy barrier for crystallization process decreases upon addition of CSNs. At lower isothermal crystallization temperatures (T_c) viz. (90–100 °C), reduced growth rates of PLA spherulites is observed. Both PLA and PLA/CSN exhibit highest crystallization rates at around ～107 °C. The hydrolytic degradation rates calculated from molecular weight reduction shows that PLA/CSN nanocomposites' degradation rates are lower as compared to PLA in acidic, neutral, and alkaline media at pH = 2, 7, and 12, respectively, due to hydrophobic nature of CSN. Scanning electron microscopy study demonstrated the surface erosion mechanism of hydrolytic degradation of PLA and PLA/CSN nanocomposites. This work provides valuable insight for the application and reclamation of PLA/CSN bionanocomposites in moist and wet working environments. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 46590.     

Microfibers nanocomposite based on polyacrylonitrile fibers/bismuth oxide nanoparticles as X-ray shielding material

The main focus of the current study was to fabricate fibrous nanocomposite based on polyacrylonitrile (PAN) fibers containing Bi₂O₃ NPs as the X-ray shielding material. Bi₂O₃ NPs were synthesized based on the solid dispersion evaporation method and dispersed into PAN polymer solution with different weight concentrations. The electrospinning technique was used to fabricate nanocomposite. The morphology, surface functional group, wettability, elemental analysis, and X-ray shielding efficacy of the fabricated nanocomposite were thoroughly evaluated. The dimeter of the fibrous nanocomposites containing 10, 20, and 30 wt% Bi₂O₃ NPs were 1.33 ± 0.08, 1.01 ± 0.11, and 1.69 ± 0.32 μm, respectively. EDX elemental analysis showed that NPs were uniformly distributed into/onto the fibers. The X-ray shielding studies showed that the prepared nanocomposites effectively attenuate the intensity of the X-ray. The entrance surface dose for the negative control was 24.10 ± 1.71 mSv and the application of the nanocomposites significantly reduced the entrance surface dose. The results showed NPs concentration-dependent CT number shift as the indication of X-ray protection and the highest value was obtained by 30 wt% NPs. The obtained results implied that the fabricated nanocomposites effectively attenuate the radiation and they could be applied as the X-ray shielding materials.     

Optimized synthesis,characterization, and antibacterial activity of an alginate–cupric oxide bionanocomposite

In this research, the structural features and optimal conditions for the synthesis of an alginate–CuO nanocomposite with the highest antibacterial activity were investigated. CuO nanoparticles (NPs) and the alginate biopolymer were synthesized chemically and biologically, respectively. Nine nanocomposite compounds were produced on the basis of the Taguchi method with different levels of CuO NPs and the alginate biopolymer nanocomposite with different stirring times. Fourier transform infrared spectroscopy, high‐resolution field emission scanning electron microscopy, and energy‐dispersive X‐ray spectroscopy analysis confirmed the formation of the nanocomposites. The nanocomposite synthesized with 8 mg/mL copper oxide NPs and 2 mg/mL alginate biopolymer with 60 min of stirring time showed the highest antibacterial activity. The results of two colony forming units and disk‐diffusion methods indicated a stronger antibacterial activity of the alginate–CuO nanocomposite compared with those of its components. The alginate–CuO nanocomposite showed the potential ability to act as an antimicrobial agent against Gram‐negative and Gram‐positive bacteria. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 45682.     

Preparation and characterization of poly(ϵ‐caprolactone‐co‐p‐dioxanone)–poly(ethylene glycol)–poly(ϵ‐caprolactone‐co‐p‐dioxanone)/bioactive inorganic particle nanocomposites

With an aim to develop injectable hydrogel with improved solution stability and enhanced bone repair function, thermogelling poly(ε‐caprolactone‐co‐p‐dioxanone)‐poly(ethylene glycol)‐poly(ε‐caprolactone–co‐p‐dioxanone) (PECP)/bioactive inorganic particle nanocomposites were successfully prepared by blending the triblock copolymer (PECP) with nano‐hydroxyapatite (n‐HA) or nano‐calcium carbonate (n‐CaCO₃). The hydrogel nanocomposites underwent clear sol–gel transitions with increasing temperature from 0 to 50°C. The obtained hydrogel nanocomposites were investigated by ¹H NMR, FT‐IR, TEM, and DSC. It was found that the incorporation of inorganic nanoparticles into PECP matrix would lead to the critical gelation temperature (CGT) shifting to lower values compared with the pure PECP hydrogel. The CGT of the hydrogel nanocomposites could be effectively controlled by adjusting PECP concentration or the content of inorganic nanoparticles. The SEM results showed that the interconnected porous structures of hydrogel nanocomposites were potentially useful as injectable scaffolds. In addition, due to the relatively low crystallinity of PECP triblock copolymer, the aqueous solutions of the nanocomposites could be stored at low temperature (5°C) without crystallization for several days, which would facilitate the practical applications. The PECP/bioactive inorganic particle hydrogel nanocomposites are expected to be promising injectable tissue engineering materials for bone repair applications. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013     

Preparation and characterization of mPEG‐g‐α‐zein biohybrid micelles as a nano‐carrier

A new kind of block copolymer micelles methoxy polyethylene glycol (mPEG) grafted α‐zein protein (mPEG‐g‐α‐zein) was synthesized. The chemical composition of mPEG‐g‐α‐zein was identified with the help of FT‐IR and ¹H‐NMR. The biohybrid polymer can self‐assemble into spherical core–shell nanoparticles in aqueous solution. Scanning electron microscopy (SEM) and atomic force microscopy (AFM) were used to investigate the self‐assembled morphology of mPEG‐g‐α‐zein. Dynamic light scattering (DLS) results showed that the particle size of mPEG‐g‐α‐zein was about 90 nm. Moreover, the nanoparticles had a very low critical micelle concentration value with only 0.02 mg/mL. Then, the anticancer drug curcumin (CUR) was encapsulated into the biohybrid polymer micelles. The in vitro drug release profile showed a zero‐order release of CUR up to 12 h at 37°C. Cell viability studies revealed that the mPEG‐g‐α‐zein polymer exhibited low cytotoxicity for HepG2 cells (human hepatoma cells). Consequently, the mPEG‐g‐α‐zein micelles can be used as a potential nano‐carrier to encapsulate hydrophobic drugs and nutrients. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 42555.     

Garlic oil–loaded PLGA nanoparticles with controllable size and shape and enhanced antibacterial activities

The present work focuses on producing polymer composite nanoparticles (NPs) composed of garlic oil (GO) and poly(lactic‐co‐glycolic) acid (PLGA) by the single emulsion/solvent evaporation (SE/SE) method and high‐speed homogenizing. Different preparation parameters were found to greatly affect the stability and size uniformity of the prepared PLGA/GO NP formulations, which were carefully controlled. Scanning electron microscopy, Fourier transform infrared spectroscopy, and UV–vis spectroscopy and dynamic light scattering and zeta potential were used to characterize the NPs. Antibacterial assessment of the prepared PLGA/GO NPs against E. coli and S. aureus was carried out. Interestingly, the NP size ranged between 201 and 319 nm, which is 10 times less than the size of the regular GO particles in bulk solution. The antibacterial activities show enhancement by 70–78% of bacterial inhibition compared with a GO bulk solution. This work sheds light on the potential use of GO NP formulations as nanobiotics and the critical NP preparation parameters that need to be considered. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 46133.     

Fabrication of antibacterial silver nanoparticle‐modified chitosan fibers using Eucalyptus extract as a reducing agent

Green chemical method could be a promising route to achieve large scale synthesis of nanostructures for biomedical applications. Here, we describe a green chemical synthesis of silver nanoparticles (Ag NPs) on chitosan‐based electrospun nanofibers using Eucalyptus leaf extract. A series of silver salt (AgNO₃) amounts were added to a certain composition of chitosan/polyethylene oxide aqueous acetic acid solution. The solutions were then electrospun to obtain nanofibrous mats and then, morphology and size of nanofibers were analyzed by scanning electron microscopy (SEM). Incubation of AgNO₃‐containing mats into Eucalyptus leaf extract led to the formation of Ag NP clusters with average diameter of 91 ± 24 nm, depicted by SEM and transmission electron microscopy. Surface enhanced Raman spectroscopy also confirmed formation of Ag NPs on the nanofibers. The mats also showed antimicrobial activity against Escherichia coli and Staphylococcus aureus bacteria with bigger inhibition zone for extract‐exposed mats against S. aureus. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 42133.     

PEGylation of MnO nanoparticles via catechol–Mn chelation to improving T1‐weighted magnetic resonance imaging application

To enhance biocompatibility and physiological stability of hydrophobic MnO nanoparticles as contrast agent of T₁‐weighted magnetic resonance imaging (MRI), dopamine‐functionalized poly(ethylene glycol) (PEG) was used to coat the surface of about 5 nm MnO nanoparticles. Although hydrophilic coating might decrease longitudinal relaxivity due to inhibiting the intimate contact between manganese of nanoparticle surface and proton in water molecules, higher longitudinal relaxivity was still maintained by manipulating the PEGylation degree of MnO nanoparticles. Moreover, in vivo MRI demonstrated considerable signal enhancement in liver and kidney using PEGylated MnO nanoparticles. Interestedly, the PEGylation induced the formation of about 120 nm clusters with high stability in storing and physiological conditions, indicating passive targeting potential to tumor and prolonged circulation in blood. In addition, the cytotoxicity of PEGylated MnO nanoparticles also proved negligible. Consequently, the convenient PEGylation strategy toward MnO nanoparticles could not only realize a good “trade‐off” between hydrophilic modification and high longitudinal relaxivity but also contribute additional advantages, such as passive targeting to tumor and long blood circulation, to MRI diagnosis of tumor. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 42360.     

Antimicrobial cytocompatible pentaerythritol triacrylate‐co‐trimethylolpropane composite scaffolds for orthopaedic implants

As of 2010, 5.3 million orthopedic surgeries are performed each year, and this number is expected to increase to 6.2 million by 2020. On average, 27.7% of all orthopedic surgeries result in infection which often leads to osteomyelitis and the loss of supporting bone. In this study, we describe two synthetic bone grafts, or augmentation methods, for a biodegradable, silver nanoparticle (SNPs) containing antimicrobial scaffolds composed of pentaerythritol triacrylate‐co‐trimethylolpropane tris (3‐mercaptopropionate) (PETA) and hydroxyapatite (HA). This osteoinductive and degradable material is designed to stimulate proliferation of bone progenitor cells, and provide controlled release of antimicrobial components. The first method, denoted as the “incorporating method,” involves dissolving SNPs in ethanol, butanol, or isopropanol and directly incorporating the particles into the scaffold prior to polymerization. The second method, “coating method,” involves submerging fabricated scaffolds into their respective SNPs‐solution and mixing for 24 h. The coating method allowed better distribution and release of SNPs from the surface of the composites when exposed to extracellular media. The in vitro release of silver for both methods was quantified by inductively coupled plasma optical emission spectroscopy (ICP‐OES). The scaffolds made by means of the coating method showed increased release of silver with respect to time; no silver leached from the scaffolds formed by the incorporating method. Use of Alamar Blue assay demonstrated that the SNPs incorporation did not affect cell viability when tested with hASCs. The scaffolds formed by the coating method inhibited the proliferation of Staphylococcus aureus 99.5% and Escherichia coli by 99.9% within 24 h. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 41099.     

Effectiveness of PANI/Cu/TiO2 ternary nanocomposite on antibacterial and antistatic behaviors in polyurethane coatings

Surfaces with antibacterial and antistatic functionalities are one of the new demands of todays' industry. Therefore, a facile method for the preparation of multifunctional polyaniline/copper/TiO₂ (PANI/Cu/TiO₂) ternary nanocomposite based on in situ polymerization is presented. This nanocomposite was characterized through the different techniques and was utilized for induction of antibacterial and antistatic properties in polyurethane coatings. Measurement of the conductivity of PANI/Cu/TiO₂ ternary nanocomposite indicated higher electrical conductivity of this nanocomposite compared to pure PANI. The antibacterial activity of the modified polyurethane coatings was tested against Gram-positive and Gram-negative bacteria which led to remarkable reduction in bacterial growth. Besides, it was observed that polyurethane coating with 2 wt % content of ternary nanocomposite has a surface electrical resistance equal 4 × 10⁸ Ω/sq which acquires surface electrical resistance of standard antistatic coatings. The final coatings were also characterized in terms of thermal and mechanical properties to investigate the effect of the ternary nanocomposite on improvement of these properties. © 2020 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020 , 137, 48825.     

Interface of polyimide–silica grafted with different silane coupling agents: Molecular dynamic simulation

In this article, the effects of different silane coupling agents: 3‐glycidyloxypropyltrimethoxysilane (GOTMS), 3‐aminopropyltriethoxysilane (APTES), and 3‐methacryloxypropyltrimethoxysilane (MPTS), on the interface between polyimide (PI) and silica (SiO₂), were investigated using molecular dynamic simulation. The results indicate that binding energy between PI molecules and SiO₂ surface mainly comes from van der Waals interaction. Proper silane coupling agents generate a thin membrane on the surface of SiO₂, which improves the thickness of the transition layer between PI molecules and SiO₂ surface. And density of the transition layer was enhanced by APTES significantly. In addition, amino group (? NH₂) improves the electrostatic interaction between PI molecules and SiO₂ surface rather than epoxy group (? CH? CH₂? O) and methacrylic oxide group (? O? CO? C(CH₃)?CH₂). As a result, APTES enhances the binding energy effectively. However, excessive silane coupling agent increases the distance between PI matrices and SiO₂, which deteriorates performance of the interface. In addition, GOTMS and MPTS generate a thick and dense membrane on SiO₂ surface, which induces the loose transition layer and poor binding energy. Overlap parameter between PI molecules and SiO₂ surface grafted with silane coupling agent can be employed to evaluate the transition layer successfully. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 45725.     

Enhancing crystallization rate and melt strength of PLLA with four‐arm PLLA grafted silica: The effect of molecular weight of the grafting PLLA chains

To improve the crystallization rate and melt strength of polylactide (PLLA), nano‐size amino silica grafted by four‐arm PLLA (4A‐PLLA) with different molecular weight was synthesized. ¹H nuclear magnetic resonance proved that 4A‐PLLA had been grafted onto the surface of SiO₂ successfully, and the grafting ratios and the degradation behaviors of the grafted SiO₂ nanoparticles (g‐SiO₂) were studied. When the grafted silica was introduced into PLLA matrix, the crystallization rate and melt strength of composites were found to be improved and the length of grafted chain played an important role. The extension rheology indicated that long grafted 4A‐PLLA on the surface of SiO₂ was more efficient in enhancing the elongational viscosity of PLLA, owing to the stronger interactions between the grafted chains and the matrix. The crystallization behavior of ungrafted silica filled composite was similar to that of neat PLA, while g‐SiO₂ played a role of nucleating agent. The crystallinities and the crystallization rates of the composites depended on the content of g‐SiO₂ and the grafted chain length of 4A‐PLLA, especially the latter. Longer grafted chain acted as nucleation site in the matrix and significantly improved the crystallization behaviors of PLLA. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 45675.     

Iodine-loaded poly(silicic acid) gellan nanocomposite mucoadhesive film for antibacterial application

Iodine-loaded poly(silicic acid) gellan nanocomposite film was fabricated and evaluated for antibacterial properties. Poly(silicic acid) nanoparticles were synthesized by condensation of silicic acid under alkaline conditions in the presence of polyvinyl pyrrolidone, phosphate ions, and molecular iodine. The nanoparticles were incorporated into gellan dispersion to prepare gellan nanocomposite film using the solvent casting method. The nanocomposite films were characterized by Fourier transformed infrared spectroscopy, thermogravimetric analysis, and X-ray diffraction studies. The results of characterization studies indicated improved thermal stability and an increase in the degree of crystallinity. The scanning electron micrographs and energy dispersive X-ray spectrum confirmed the uniform dispersion of silica and iodine in the nanocomposite films. The analysis of physical and mechanical properties revealed the enhanced tensile strength, moisture resistance, and higher folding endurance of poly(silicic acid) gellan nanocomposite films as compared to gellan film. Further, the iodine-loaded poly(silicic acid) gellan nanocomposite films showed good antibacterial activity against Staphylococcus aureus and Escherichia coli and effective mucoadhesive strength. The results indicate that iodine-loaded poly(silicic acid) gellan nanocomposite mucoadhesive film can be used for potential antibacterial applications in pharmaceuticals.     

Silver‐releasing and antibacterial activities of polyphenol‐based polyurethanes

Inspired by mussel adhesive proteins, catechol functional groups play an important role in the ability of the mussel to adhere to organic and inorganic surfaces. A novel functional polyurethane (PU) based on hydrolysable tannins that contain a number of catechol groups was successfully synthesized and characterized. These catechol groups were used as a reducer for Ag (I) to form Ag (0), and to prepare polyurethane/silver nanoparticles composites. These kinds of polyurethane containing Ag nanoparticles showed obvious inhibition of bacterial growth because of the conjunct actions of the well‐known antibacterial property of silver and the antifouling property of PEG. It is possible for these materials to be applied widely into antibacterial adhesive coatings for surface modification due to their low cost and the material‐independent adhesive property of catechol groups in tannins. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 41349.     

Surface‐pegylated chitin whiskers as an effective additive to enhance the mechanical properties of recycled ABS

The recyclability of materials is a key issue related to the use of polymers in the automotive and electronic industries, among others. The multiple thermal and mechanical operations used in recycling can cause severe damage to the molecular architecture and microstructure of polymers that frequently leads to a reduction in their mechanical properties, which restricts their recyclability. In this work, nanocomponents (whiskers) derived from chitin were surface‐modified by grafting different molar masses of methoxylated poly(ethylene glycol) (mPEG). The modified chitin whiskers were then incorporated into reprocessed ABS (acrylonitrile–butadiene–styrene) to yield nanocomposites with 0.5% (mass/mass) whiskers. The obtained whiskers and nanocomposites were investigated using techniques such as transmission electron microscopy, atomic force microscopy, scanning electron microscopy, infrared spectroscopy, and thermogravimetric analysis. The properties of the nanocomposites were also investigated using tensile tests and dynamic mechanical tests. The results show that the surface‐modified chitin whiskers with high molar mass mPEG grafts increased the strength, elongation at break, and stiffness of the reprocessed ABS over virgin and reprocessed ABS and reprocessed ABS nanocomposites with unmodified whiskers. This indicates that the use of surface‐modified chitin whiskers can be valuable in improving the mechanical properties of recycled polymers and, consequently, enhancing their recyclability. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 42463.     

Electrochemical behavior of multifunctional graphene–polyimide nanocomposite film in two different electrolyte solutions

The effect of solvent on specific capacitance, bulk resistance, and charge/discharge capacity of graphene/polyimide composite films is studied by electrochemical methods. Composite films are synthesized by in situ condensation polymerization of poly (amic acid) in the presence of 50 wt % partly exfoliated graphene sheets followed by thermal curing at 250°C. Raman spectrum of the exfoliated graphene sheets show an increase in the ratio of I_D to I_G peak intensities from 0.167 to 0.222, suggesting increased defects in graphene basal planes. Electrochemical measurements carried out by using 0.4M potassium hexafluorophosphate (KPF₆) dissolved in propylene carbonate and N‐methylpyrrolidone at 25°C show that the composite system exhibits both pseudocapacitance and supercapacitance behaviors, with an average capacitance of 40 and 36.5 F g^?1, respectively. Bulk resistance of the composite obtained by using KPF₆–propylene carbonate electrolyte solution is 300% lower than that obtained in KPF₆–N‐methylpyrrolidone solution, with a fairly stable specific capacity of 85 μAhr g^?1, with 80% retention observed after 30 charge–discharge cycles. Fourier transform infrared spectroscopy measurements show shifts in the cyclic imide carbonyl peak from 1778 to 1774 cm^?1, which suggests that some form of interaction exists between the graphene and polyimide. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 42673.     

ZnO microparticle-loaded chitosan/poly(vinyl alcohol)/acacia gum nanosphere-based nanocomposite thin film wound dressings for accelerated wound healing

The present study deals with the development of novel ZnO microparticle-loaded chitosan/poly(vinyl alcohol)/acacia gum nanosphere-based nanocomposite thin films through electrospraying and evaluation of their potential use in wound healing applications for skin. ZnO microparticles were synthesized and used as bioactive agents. Morphology, size distribution, structure, and dispersion of the synthesized ZnO microparticles were analyzed by scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy, Fourier transform infrared spectroscopy, and transmission electron microscopy (TEM). ZnO microparticles were incorporated into the ternary nanocomposite films by electrospraying technique. Thermogravimetric analyses reveal that incorporation of ZnO microparticles into the nanocomposite structure improves the thermal stability. Mechanical analyses show that tensile strength reaches to the maximum value of 12.75 MPa with 0.6 wt % ZnO content. SEM and TEM micrographs demonstrate that the nanocomposite films consist of nanospheres with nanocapsular structures whose sizes are mostly between 250 and 550 nm. Viability tests established prevailing cellular performance of the fibroblasts on 0.6 wt % ZnO microparticle-loaded nanocomposite films with a viability percentage of 160% compared to the control group. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020 , 137, 48445.     

Prediction of long‐term mechanical properties of PVDF/BaTiO3 nanocomposite

Low elastic modulus of polyvinylidene fluoride (PVDF) is a major drawback that can be compensated by adding nanoparticles. This work reports the long‐term mechanical behavior of PVDF nanocomposite containing BaTiO₃ nanoparticle that is evaluated by creep test. The nanocomposite morphology was characterized by scanning and transmission electron microscopy techniques. The dynamic mechanical analysis (DMA) was employed to study the viscoelastic behavior of nanocomposite in a wide range of temperatures and frequencies. According to the creep tests, nanocomposite reduced the rate of the creep compliance at different temperatures. Moreover, the creep compliance for the nanocomposite sample decreased slightly in comparison with neat PVDF. Comparing the Burger's model and experimental results, the elastic and viscous parameters revealed the exactly opposite behavior with increasing temperature. The effect of frequencies on storage moduli of samples was investigated based on time–temperature superposition (TTS) method. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40596.     

Effect of silk nano‐disc dispersion on mechanical,thermal, and barrier properties of poly(lactic acid) based bionanocomposites

Exacerbated environmental concerns about petroleum‐based plastics provide the impetus to foster sustainable poly(lactic acid) (PLA) based food packaging. Nonetheless, PLA has its foibilities such as its brittleness, higher gas permeability, and slow crystallization. With the intent to mitigate the above shortcomings, we report a maiden effort for the fabrication of PLA/crystalline silk nano‐discs (CSNs) based bionanocomposites by melt‐extrusion for high temperature engineering and food packaging applications. Acid hydrolyzed silk fibroin from muga silk (Antheraea assama) yields CSNs, a crystalline hydrophobic discotic nanofiller with diameter of ～50 nm and thickness ～3 nm. At optimum loadings of 1 wt % uniform dispersed CSNs with percolated network structures covering the entire matrix can be seen. Due to enhanced crystal nucleation density, water vapor, and oxygen permeability reduced by ～30% and ～70%, respectively. Enhancement in toughness, percentage elongation, and tensile strength up to ～65%, ～40%, and ～10%, respectively, is obtained. Onset of thermal decomposition for the PLA/CSN improved ～10 °C, confirming the role of CSN in enhancing melt stability. Accordingly, this investigation renders a novel non‐invasive approach for increasing the crystallinity with improvement in thermomechanical and barrier properties which make this bionanocomposite, a promising candidate for food packaging applications. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 46671.     

Hydrophilic goethite nanoparticle as a novel antifouling agent in fabrication of nanocomposite polyethersulfone membrane

The goethite nanoparticle was used as a multifunctional additive to fabricate antifouling polyethersulfone (PES) nanofiltration membranes. The goethite/PES membranes were synthesized via the phase inversion method. The scanning electron microscopy (SEM) photographs showed an increase in pore size and porosity of the prepared membranes with blending of the goethite. The static water contact angle measurements confirmed a hydrophilic modification of the prepared membranes. With increase in the goethite content from 0 to 0.1 wt %, the pure water flux increased up to 12.7 kg/m² h. However, the water permeability decreased using high amount of this nanoparticle. Evaluation of the nanofiltration performance was performed using the retention of Direct Red 16. It was observed that the goethite/PES membranes have higher dye removal capacity (99% rejection) than those obtained from the unfilled PES (89%) and the commercial CSM NE 4040 NF membrane (92%). In addition, the goethite/PES blend membranes showed good selectivity and antifouling properties during long‐term nanofiltration experiments with a protein solution. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 43592.