Synergistic effect of silica nanoparticles in the matrix of a poly(ethylene glycol) diacrylate coating layer for the surface modification of polyamide nanofiltration membranes

In this study, a commercial polyamide nanofiltration membrane was modified by a combination of poly(ethylene glycol) diacrylate (PEGDA) in situ polymerization and silica (SiO₂) nanoparticles. The PEGDA layer was polymerized on the surface of the membranes alone or mixed with SiO₂ nanoparticle. The surface modification influence on the water flux, salt rejection, and antifouling behavior was investigated. The effects of the nanoparticles and PEGDAylation on the membrane properties were characterized by Fourier transform infrared spectroscopy, contact angle measurement, and scanning electron microscopy analyses. The membranes that were in contact with 30 wt % PEGDA and then treated with ultraviolet light for 5 min had a better water flux than the unmodified membrane. The fouling resistance of the membranes to a foulant solution containing bovine serum albumin, humic acid, and sodium sulfate were studied, and the results show that the membrane with 30 wt % PEGDA had better antifouling properties. After the weight percentage of PEGDA for the prepolymerization solution was optimized (30 wt % was the best), the SiO₂ nanoparticle concentration in the prepolymerization matrix was optimized. The presence of SiO₂ nanoparticles in the PEGDA layer increased the membrane flux. The maximum water flux and good antifouling properties were obtained for 0.5 wt % SiO₂ nanoparticles in a 30 wt % PEGDA layer. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 43793.     

Improved hydrothermal aging performance of glass fiber-reinforced polymer composites via silica nanoparticle coating

The long-term exposure to a hot and humid environment severely damages the bonding integrity of fiber-reinforced polymer composites and thus significantly degrades their mechanical performances. In this work, we aim to develop an improvement procedure for effectively enhancing the bonding strength in glass fiber-reinforced polymers (GFRPs). Glass fibers were coated with a thin layer of silica nanoparticles of different concentrations by the use of the evaporative deposition method. Micromorphological comparisons in terms of scanning electron microscope imaging demonstrate significant improvements on the surface roughness of glass fibers. With the coated glass fibers, GFRP composite laminates were designed, molded through the vacuum-assisted resin infusion technique, and experimentally tested for quantitatively studying their hydrothermal aging performance. The water absorption tests conducted for three exposure temperatures suggest that both the water diffusion rate and the equilibrium water content can be effectively reduced due to the introduction of the silica coating. With increased exposure temperatures, however, the desired reductions become much less significant. A so-called water-channel diffusion mechanism along fiber/resin interfaces was proposed to explain the coupling effects of silica coating and exposure temperature. Reductions of water diffusion rate and equilibrium water content were expected to slow down the hydrothermal aging performance of GFRPs. For this purpose, both uniaxial tensile test and three-point bending test were subsequently performed on GFRP specimens that have been subjected to different coating concentrations, exposure temperatures, and exposure durations. When compared with untreated GFRP specimens, both experiments demonstrate that the residual strength and stiffness can be effectively promoted through coating a thin layer of silica nanoparticles on glass fiber surfaces. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 137, 48652.     

Facile preparation of homogenous waterborne poly(urethane/acrylate) composites and the correlation between microstructure and improved properties

Homogenous waterborne polyurethane/polyacrylate emulsions were synthesized based on the prepared polyurethane and polyacrylate through a facile process. The attention was attracted to the miscibility and performance of waterborne polyurethane and polyacrylate. The structures and properties of waterborne polyurethane and waterborne polyurethane/polyacrylate samples were characterized by using Fourier transform infrared spectroscopy, transmission electron microscope, X-ray photoelectron spectroscopy, X-ray diffractometer, thermogravimetric, and so forth, as well as solid content and tensile testing. The results showed that the micro morphology of waterborne polyurethane/polyacrylate emulsion presented single-phase structure with the stoichiometric polyacrylate content increasing from 33% to 80% to waterborne polyurethane. The waterborne polyurethane/polyacrylate films surface is rich in polyacrylate phase. Meanwhile, waterborne polyurethane/polyacrylate composites showed significant improvement in thermal stability and elongation at break, smaller particle size and narrower particle size distribution comparing with waterborne polyurethane.     

Polymerized high internal phase emulsion monoliths for the chromatographic separation of engineered nanoparticles

PolyHIPEs of ethylene glycol dimethacrylate (EGDMA) and styrene/divinylbenzene were prepared by polymerization of water‐in‐oil high internal phase emulsions (HIPEs) within high pressure liquid chromatography (HPLC) columns. The columns were incorporated into a HPLC system affixed to an inductively‐coupled plasma mass spectrometer, and their potential for the separation of engineered nanoparticles was investigated. Triplicate injections of 5 and 10 nm gold particles injected onto a poly(styrene‐co‐divinylbenzene) polyHIPE column produced an average difference in retention time of 135 s. On a poly(EGDMA) column, triplicate injections of dysprosium containing polystyrene particles of 52 and 155 nm produced a difference in retention time of 8 s. In both cases the smaller particles eluted from the column first. Comparison, using scanning electron microscopy, of the polyHIPE columns after the separations, against freestanding monoliths produced from the same HIPEs, revealed no apparent change in the internal porous structure of the polyHIPEs. © 2015 The Authors Journal of Applied Polymer Science Published by Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 132, 41229.     

The influence of in situ synthesized nanoparticles on microstructure and compression properties of polymer foams during supercritical carbon dioxide foaming

The influence of in situ synthesized nanoparticles on the microstructure and compression properties of polymer foams during supercritical carbon dioxide foaming has been investigated. The in situ synthesized Ag nanoparticles were chosen to be heterogeneous nucleating agent. For achieving our target, the influence of the nanoparticle size on the cell structure and the nucleation mechanism has been detailed discussed firstly. The results show that the in situ synthesized nanoparticles can be heterogeneous nucleation agent to improve the cell density of the PMMA‐based foams. The particle size is able to reduce to the critical size of heterogeneous nucleation agent and, then, can highly improve the cell density of the foams. The Ag nanoparticles with average size of 2.2 nm led to 85% increase in compressive strength of the foams. The improvement of strength of the polymer matrix and the microstructure of the foams can lead to the remarkable increase in the mechanical properties of the foams. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 44629.     

Preparation and anticorrosion resistance of a self-curing epoxy nanocomposite coating based on mesoporous silica nanoparticles loaded with perfluorooctyl triethoxysilane

Organic coatings are prone to failure due to diffusion of the corrosion media toward the metal surface through the microcracks caused by internal and environmental stresses especially in immersion environment. In order to extend the service lifetime of organic coatings, we developed a self-curing epoxy resin/perfluorooctyl triethoxysilane (POTS)-loaded mesoporous silica nanoparticles (MSNs) nanocomposite (SEP/POTS-MSNs) coating, by embedding the POTS-loaded MSNs (POTS-MSNs) into an SEP resin. Fourier transform infrared, X-ray photoelectron spectroscopy, and Brunauer–Emmett–Teller analyses were conducted to confirm the successful loading of POTS in the MSNs. Thermogravimetric analysis was used to characterize the loading amount of POTS. The corrosion protection properties of the SEP, SEP/MSNs, and SEP/POTS-MSNs coatings were evaluated by electrochemical impedance spectroscopy and potentiodynamic polarization tests. The results indicate that the SEP/POTS-MSNs coating with only 30 μm thickness showed corrosion resistance with Z _{f = 0.01 Hz} of 4.7 × 10⁸ Ω/cm² and i_corr of 0.026 nA/cm² after 58 hr of immersion in boiling water, which were both two orders of magnitude higher than those of the SEP coating. The SEP/POTS-MSNs coating combines the advantages of the SEP coating and the POTS-MSNs. We anticipate that the SEP/POTS-MSNs coating has promising potential for use in immersion environments.     

Preparation of polyvinylpyrrolidone/graphene oxide/epoxy resin composite coatings and the study on their anticorrosion performance

Waterborne epoxy resin (EP) is often used as anticorrosive coating in the industrial field. However, small holes and gaps can be formed during the curing process. The corrosive medium easily penetrates the anticorrosive coating and corrodes the metal matrix. Herein, polyvinylpyrrolidone (PVP) and graphene oxide (GO) were doped into EP to improve the shielding and resistance to corrosive media. The composite coatings were prepared successfully by solution blending method. In the PVP/GO composite materials, original spatial structure of GO was changed and the composite was mainly combined by covalent bonding. The surface morphology of hybrid filler was flat and uniform, and the structural defects of GO was reduced. Compared with single-layer anticorrosive coating, the corrosion potential of PVP/GO/EP coating moved forward and the corrosion current density decreased. The ideal corrosion resistance of PVP/GO/EP composite coatings was mainly because agglomeration of GO sheet was obviously avoided after it was modified by PVP. Furthermore, the hybrid filler can be uniformly dispersed in the aqueous EP. It blocked the gaps and holes inside the coatings, which could contribute to form anticorrosive coatings.     

Preparation of zirconia loaded poly(acrylate) antistatic hard coatings on PMMA substrates

Zirconia (ZrO₂) nanoparticles were synthesized by hydrolysis and condensation of zirconium‐n‐propoxide (ZNP) in 1‐propanol at the presence of methacrylic acid (MA), serving as a chelating agent for ZNP. The formed nanoparticles were chemically modified by the UV‐curable coupling agent, 3‐(trimethoxysilyl)propyl methacrylate (MSMA). The modified particles were then crosslinked with the hexa‐functional monomer, dipentaerythritol hexaacrylate (DPHA), to produce transparent antistatic hard coatings on poly(methyl methacrylate) (PMMA) substrates. Sizes of the modified particles, as determined by the dynamic light scattering technique, fell over a small range of 2–20 nm. Chemical analyses of the particles and the coatings were performed using FTIR and/or solid ²⁹SiNMR spectroscopy. Surface resistivities of the coatings were measured, and the results indicated that with inclusion of 10 wt % modified zirconia, surface resistivity of ～10⁹ Ω/sq could be achieved, which amounted to ～6 order magnitude lower than that of the particle‐free polymeric binder. Furthermore, this antistatic coating was very hard with pencil hardness of 8–9H, and attached perfectly to the PMMA substrate according to the peel test. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 42411.     

Inorganic nanoparticles incorporated in polyacrylonitrile-based mixed matrix membranes for hydrophilic,ultrafast, and fouling-resistant ultrafiltration

Mixed matrix membrane (MMM) structures and performances are greatly affected by the distribution of nanoparticles in the polymeric matrix. Until now, there has been little research on the effects of nanoparticle distribution states on polyacrylonitrile (PAN)-based MMM structures and performances. In this paper, different intermolecular interactions between nanoparticles and PAN molecules were generated by in situ fabricated amino-functionalized SiO₂ and TiO₂ nanoparticles to create absolutely different distribution states of nanoparticles in a PAN matrix. The results indicated that, due to the strong interactions between amino and cyano groups, SiO₂ is distributed in the PAN membranes homogeneously, while most of the TiO₂ migrates to the membrane's top surfaces or the walls of pores or even escape from the membranes during the nonsolvent index phase separation (NIPS) process. PAN-TiO₂ MMMs have more hydrophilic top surfaces, higher porosity, larger mean pore size, and stronger antifouling performances than pure PAN and PAN-SiO₂ membranes. The PAN-TiO₂ MMMs have an ultrahigh water flux of 1204.6 L/(m² h), which is more than 44 times that of PAN membranes. And the good pore structures and hydrophilicity of the membranes derived from special interactions between in situ TiO₂ nanoparticles and PAN molecules can give high-performance PAN-based ultrafiltration membranes a bright future. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 47902.     

Exfoliated and functionalized boron nitride nanosheets towards improved fire resistance and water tolerance of intumescent fire retardant coating

In this work, the exfoliated and functionalized boron nitride (f-BN) nanosheets were prepared via facile treatment and used in the intumescent fire retardant (IFR) coatings, which offer passive fire protection to the steel. To acquire the best fire resistance, the formula of the coating was optimized using response surface methodology (RSM) based on central composite design. According to the result, the optimal sample, with 36.2 wt% ammonium polyphosphate (APP), 27.4 wt% pentaerythritol (PER), 16.8 wt% melamine (MEL), and 7.9 wt% f-BN, was prepared and its fire resistance was tested in our lab. At the end of fire resistance test, the backside temperature of optimal sample was only 185.2°C, which was very close to the RSM-predicted result, indicating satisfactory fire resistance. During the test, the coating decomposed to form an intumescent char layer with high graphitization degree and compactness, thus suppressing the transfer of heat and protecting the underlying steel. In addition, the optimal coating possessed great water tolerance and thermal stability, and its water contact angle and char yield reached up to 66.7° and 40.5%, respectively. Hence, this IFR coating with satisfied fire retardancy and water tolerance has broad practical future in the fire safety of steel structure.     

Hollow mesoporous silica capsules loaded with copper,silver, and zinc oxide nanoclusters for sustained antibacterial efficacy

Intensive and overuse of antibiotics during the last years has triggered a distinct rise in antibiotic resistance worldwide. In addition to the newly developed antimicrobials, there is a high demand for alternative treatment options against persistent bacterial infections. The biocidal impact of metal ions like copper (Cu²⁺), silver (Ag⁺), and zinc (Zn²⁺), also known as the oligodynamic effect has been used for ages to kill or inhibit the growth of microorganisms and to employ long-term prevention strategies against their biological antagonists. Herein, we report on the synthesis of Cu, Ag, and Zn metal and corresponding oxide nanoparticles immobilized on hollow mesoporous silica capsules (HMSCs) obtained by a hard-template assisted sol-gel synthesis followed by reduction of appropriate metal salts in the presence of HMSCs. Compartmentalization of nanosized metal and oxide clusters in Ag@HMSCs, Cu@HMSCs, and ZnO@HMSCs particles prevented their agglomeration and offered high release kinetics of metal ions between 2.0 and 3.7 mM during 24 h, as monitored by UV-vis analyses. The distribution and morphology of pristine and metal functionalized HMSCs were evaluated by transmission electron microscopy analysis revealing the successful synthesis of Ag, Cu, and ZnO nanoparticles supported on HMSCs. X-ray photoelectron spectroscopy revealed that mainly Cu(II), Ag(0), and Zn(II) species were present in the modified HMSCs. In addition to the surface attachment of preformed metal (Ag and Cu) and metal oxide (ZnO) cluster, nucleation of metal nanoparticles inside the void of HMSCs provided an internal reservoir which allowed for a time-dependent release of metal ions through slower dissolution rates leading to a long-term and sustained bacterial inhibition over several hours. The high antimicrobial efficiency of Ag@HMSCs, Cu@HMSCs, and ZnO@HMSCs particles was investigated toward both Gram-positive (Bacillus subtilis) and Gram-negative (Escherichia coli) bacteria by INT assays showing a complete growth inhibition for both bacteria types after 24 h. While Ag@HMSCs and Cu@HMSCs showed a higher susceptibility against Gram-negative bacteria, ZnO@HMSCs showed a higher susceptibility against Gram-positive bacteria. This demonstrates the promise of metal-loaded capsules as antibacterial delivery vehicles with dual-mode time-release profiles being potential alternatives for antibiotic drugs.     

Pebax-based mixed matrix membranes loaded with graphene oxide/core shell ZIF-8@ZIF-67 nanocomposites improved CO2 permeability and selectivity

In order to facilitate CO₂ transport in Pebax-based membranes, graphene oxide (GO)/core shell ZIF-8@ZIF-67 nanocomposites were loaded in Pebax copolymer to improve CO₂ permeability and selectivity. The 0.5 wt% GO doped core shell ZIF-8@ZIF-67, which gave highest CO₂ adsorption capacity of 1.12 mmol/g, was used as nanocomposite. The incorporated GO/core shell ZIF enhanced CO₂ adsorption via unsaturated metal sites (Zn-O or Co-O), because O atoms in GO substituted for N atoms coordinated with Zn and Co single atoms in core shell ZIF-8@ZIF-67. Positron annihilation lifetime spectroscopy indicated that GO-templated core shell ZIF nanocomposites generated extra free volume and provided low-resistance channels to facilitate CO₂ transport. Fourier transform infrared spectroscopy analysis revealed that hydrogen bonds were generated between Pebax polymer chains and GO-templated core shell ZIF which improved swelling resistance and reduced interface defects. Therefore, Pebax-based MMMs loaded with 5 wt% GO/core shell ZIF-8@ZIF-67 exhibited optimum CO₂ permeability (173.2 barrers) and ideal selectivity of CO₂/N₂ (61.9) and CO₂/H₂ (11.6), which were 99.7%, 66.4%, and 20.8% higher than Pebax membranes and surpass Robeson 2008 upper bound. The tensile strength increased by 17.6% to 28.8 MPa and elongation at break increased by 7.61%–554.6% when pure Pebax membranes were incorporated with 2.5 wt% GO/core shell ZIF-8@ZIF-67.     

Superhydrophobic durable coating based on UV‐photoreactive silica nanoparticles

Superhydrophobic surfaces can be obtained by tailoring both the chemistry and roughness topography, mimicking the Lotus leaf characteristics. Most of the synthetic superhydrophobic surfaces reported have been composed of micro and nanoparticles (NPs) embedded in polymer‐based coatings. The particles which tailor the topography are bonded to the base polymers by weak secondary forces. Consequently, the topography integrity is highly affected by handling and surface drag making them unsuitable for long term applications. This work is focused on promoting covalent bonding between the NPs and the base polymer to obtain durable superhydrophobic surfaces. The rough topography was achieved by ultraviolet (UV) curing of SiO₂ NPs containing a photoreactive benzophenone moiety in addition to methylated fumed silica NPs which can bind covalently to the polymer base coating, on UV radiation. The hydrophobic chemistry was obtained by fluoroalkylsilane top coating. Coating durability was evaluated using surface air drag and accelerated weathering conditions (UV radiation, humidity and temperature). Results indicated that the proposed approach resulted in superhydrophobic surfaces having high contact angle (>150°) and low sliding angle (<10°) with improved long term durability. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 41122.     

Fabrication and optimization of EGCG‐loaded nanoparticles by high pressure homogenization

In this study, we investigated the effects of the number of high pressure homogenization cycles and alginate (AG)‐to‐chitosan (CS) ratio on the physicochemical properties (mean size, polydispersity index, surface charge, encapsulation efficiency, and free radical scavenging) of (‐)‐epigallocatechin‐3‐gallate (EGCG)‐loaded nanoparticles. Nanoparticles prepared with alginate and chitosan concentrations of 0.01% and three cycles of high pressure homogenization exhibited a small size (293 nm) and a zeta potential of +37.49 mV, and were thus considered to be optimal for encapsulation. The highest encapsulation efficiency of 80.1% was achieved by using an EGCG concentration of 100 µg/g, which also resulted in the highest 2,2‐diphenyl‐1‐picrylhydrazyl (DPPH) radical scavenging activities of 81.8% and 69.3% for pH 2.6 and pH 6.9, respectively. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 43269.     

Effects of TiO2 nanoparticles on the photodegradation of poly(lactic acid)

Photodegradable poly(lactic acid) (PLA)/titanium dioxide (TiO₂) nanocomposites could be utilized as an eco‐friendly material. The photocatalytic degradation was investigated under accelerating artificial ultraviolet irradiation conditions for the period up to 100 days according to GB/T16422.3/ISO 4892.4. The change of surface color, gloss loss, morphology, weight loss, intrinsic viscosity, chemical structure, mechanical properties at different irradiation times were verified via solid reflection spectrophotometer, scanning electron microscopy, Ubbelohde viscometer, Fourier transform infrared spectrometer, and tensile test. The structural change accompanied by the degradation of the irradiated samples clearly showed that the photodegradation of PLA/TiO₂ nanocomposites process was via a bulk erosion mechanism. The photodegradability of PLA/TiO₂ samples was higher than that of pure PLA and benefitted a lot from a good dispersion of TiO₂ nanoparticles. The present study suggests that the photodegradation of PLA could be controlled by loading dispersed g‐TiO₂ nanoparticles. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 46509.     

Simultaneously reinforcing and toughening poly(lactic acid) by incorporating reactive melt-functionalized silica nanoparticles

Simultaneously reinforcing and toughening poly(lactic acid) (PLA) was carried out by adding a small amount of functionalized SiO₂ (f-SiO₂) with grafting degraded PLA chains in this work. Typically, the high shear force and high temperature condition of melt blending were employed to accelerate the degradation of PLA and graft the degraded PLA chains onto SiO₂.The structure characterizations revealed that large quantity of degraded PLA chains were grafted onto the surface of SiO₂ by transesterification, condensation, and esterification reactions during melt blending. Due to the improvement in dispersion and interfacial interaction in PLA matrix, the f-SiO₂ exhibited an effective reinforcing and toughening effect for PLA, where the tensile strength, elongation at break, and impact toughness of PLA/f-SiO₂ nanocomposite increased by 14.9, 47.8, and 30.3% compared to neat PLA. Besides, the degree of crystallinity of PLA was significantly improved by the added f-SiO₂, which also contributed to improving mechanical properties. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020 , 137, 48834.     

Dual‐stimuli‐responsive polymer‐coated mesoporous silica nanoparticles used for controlled drug delivery

In this article, a temperature‐ and pH‐responsive delivery system based on block‐copolymer‐capped mesoporous silica nanoparticles (MSNs) is presented. A poly[2‐(diethylamino)ethyl methacrylate)] (PDEAEMA)‐b‐poly(N‐isopropyl acrylamide) (PNIPAM) shell on MSNs was obtained through the surface‐initiated atom transfer radical polymerization. The block copolymer PDEAEMA‐b‐PNIPAM showed both temperature‐ and pH‐responsive properties. The release of the loaded model molecules from PDEAEMA‐b‐PNIPAM‐coated MSNs could be controlled by changes in the temperature or pH value of the medium. The as‐desired drug‐delivery carrier may be applied to biological systems in the future. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 42395.     

Carbon fiber reinforced polymer metallization via a conductive silver nanowires polyurethane coating for electromagnetic shielding

For electromagnetic shielding in space environment, the metallization of carbon fiber reinforced polymer (CFRP) is required. A specific attention is paid due to the thermal expansion coefficient difference between substrate and metal coating. A surface metallization of a CFRP has been elaborated by electrodeposition. This study presents an original process based on an electrically conductive polymer coating elaborated from a polyurethane matrix filled with a low content of silver nanowires (<10%vol). A continuous and adherent deposit is obtained by an optimization of the electroplating parameters. A minimal volume fraction was determined at 3%vol associated with an applied current density estimated near 0.1 A/dm². The growth speed is 7 μm/h at 0.1 A/dm². The adhesion was checked in severe environmental conditions (−196 to 165°C). The effectiveness shielding obtained with this solution reaches an attenuation value higher than 90 dB between 1 and 26 GHz necessary for space communication applications.     

Imparting antimicrobial properties to natural rubber latex foam via green synthesized silver nanoparticles

The green synthesis of silver nanoparticles (AgNPs) in centrifuged natural rubber latex (NRL) by in situ reduction of silver nitrate by NRL is described. The synthesis of AgNP within NRL was successfully carried out without the addition of any reducing agent or stabilizers. The modified AgNP incorporated with centrifuged NRL (GAgNP_NRL) was used to make NRL foam (NRLF) by the Dunlop production method. An ultraviolet–visible (UV‐Vis) spectrophotometer analysis, Zeta potential analysis data and transmission electron micrograph analysis proved that the modified centrifuged NRL consisted of stable nanometer‐sized silver particles. A scanning electron microscopic (SEM)/energy‐dispersive X‐ray spectroscopy (EDX) analysis and UV‐Vis analysis of a latex film made out of the modified GAgNP_NRL compound showed nano‐sized silver particles inside the rubber matrix. The final product of the NRLF (GAgNP_NRLF) made out of the GAgNP_NRL compound was tested for antimicrobial properties against gram‐negative Escherichia coli, gram‐positive Staphylococcus aureus and Staphylococcus epidermidis. The resultant GAgNP_NRLF strongly inhibited the bacteria. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40155.     

Fabrication of regenerated cellulose nanoparticles/waterborne polyurethane nanocomposites

Regenerated cellulose nanoparticles (RCNs) are ideal materials for new biomass polymer composites industries. RCNs and composites of RCNs and water‐borne polyurethane (RCN/WPU) were prepared using a facile and environmentally friendly approach without the use of any harmful chemicals. The morphological, thermal, and mechanical properties of the RCN/WPU nanocomposite were analyzed by scanning electron microscopy (SEM), transmission electron microscopy (TEM), thermogravimetric analysis (TGA), rheometer, wide‐angle X‐ray diffraction, and enzymatic hydrolysis. RCNs exhibited low crystallinity upon regeneration with an NaOH‐based aqueous solution, and were identified by SEM and TEM to consist of the more thermodynamically stable cellulose form. TGA showed that the thermal stability of RCN/WPU nanocomposites was increased by the addition of RCNs. Finally, enzymatic hydrolysis using cellulase indicated that the biodegradability of RCN/WPU nanocomposites was also improved. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 46633.