We report a facile synthesis for lignin/titanium dioxide (TiO) nanoparticles (LT NPs) at room temperature by confining assembly of lignin macromolecules. The LT NPs had a uniform nanosize distribution (average diameter ∼ 68 nm) and were directly employed as multifunctional nanofillers to reinforce a waterborne polyurethane wood coating (WBC). X-ray diffraction, Fourier-transform infrared spectroscopy, and X-ray photoelectron spectroscopy revealed the mechanism by which formed TiO confined lignin assembly.
View Article and Find Full Text PDFThe technical synergy between flexible sensing paper and triboelectric nanogenerator (TENG) in the next stage of artificial intelligence Internet of Things engineering makes the development of intelligent sensing paper with triboelectric function very attractive. Therefore, it is extremely urgent to explore functional papers that are more suitable for triboelectric sensing. Here, a cellulose nanocrystals (CNCs) reinforced PVDF hybrid paper (CPHP) is developed by electrospinning technology.
View Article and Find Full Text PDFThe highly efficient extraction of cellulose from lignocellulose with an excellent yield of 95.2 % and purity of 96.7 % was demonstrated using acid-catalyzed fractionation with aqueous butanediol.
View Article and Find Full Text PDFMembranes for water remediation require structural stability, efficient operation, and durability. In this work, we used cellulose nanocrystals (CNC) to reinforce hierarchical nanofibrous membranes based on polyacrylonitrile (PAN). Hydrolysis of the electrospun nanofibers (H-PAN) enabled hydrogen bonding with CNC and provided reactive sites for grafting cationic polyethyleneimine (PEI).
View Article and Find Full Text PDFThe simultaneous downstream valorization of cellulose and lignin is an important aspect of efficiently extracting value from lignocellulose. The present work, we demonstrated the preparation of a novel bio-based filler by the co-assembly of cellulose and lignin obtained from a one-pot ethanosolv lignocellulose fractionation process. The cellulose was valorized by forming cellulose nanocrystals (CNCs) through simple bleaching and ultrasonication processes.
View Article and Find Full Text PDFThe cellulose nanocrystals (CNC) has attracted widespread attention in reinforced materials. However, the application of CNC in electrospinning has been limited due to its self-polymerization. Herein, a cobweb-like nanofibrous membrane was fabricated by electrospinning the polyacrylonitrile (PAN) and sulfydryl-functionalized CNC (SC).
View Article and Find Full Text PDFBamboo fibers (BFs)-reinforced epoxy resin (EP) composites are prepared by resin transfer molding (RTM). The influence of BFs surface modification (NaOH solution or coupling agents, i.e.
View Article and Find Full Text PDFCellulose nanocrystals/chitosan/polyvinyl alcohol (CNC/CS/PVA) composite nanofibrous films were prepared while using an electrospinning technique and successfully thiol-functionalized. Then, the modified films were used for the sorption-desorption of Cu(II) and Pb(II) ions. Subsequently, the adsorption capacity of the films was investigated by changing the CNC loading level, solution pH, and adsorption time.
View Article and Find Full Text PDFIn this work, an easy way to prepare the polylactic acid (PLA)/wheat straw fiber (WSF) composite was proposed. The method involved uses either the dopamine-treated WSF or the two-step montmorillonite (MMT)-modified WSF as the filler material. In order to achieve the dispersibility and exfoliation of MMT, it was modified by 12-aminododecanoic acid using a two-step route.
View Article and Find Full Text PDFAn electrospinning process was utilized to fabricate composite nanofibers of poly(methyl methacrylate) (PMMA) reinforced with cellulose nanocrystals (CNCs). The effect of environmental relative humidity on the microstructure of CNC/PMMA nanofibers was investigated. Results showed that fiber surfaces of CNC/PMMA appeared smooth.
View Article and Find Full Text PDFThe agglomeration of silver nanoparticles (AgNPs) results in poor antibacterial performance, and the accumulation of silver in the human body threatens human health. Preparing a matrix is a technique worth considering as it not only prevents the aggregation of AgNPs but also reduces deposition of AgNPs in the human body. In this paper, carboxy-cellulose nanocrystals (CCNC) were prepared by a simple one-step acid hydrolysis method.
View Article and Find Full Text PDFUniform poly(lactic acid)/cellulose nanocrystal (PLA/CNC) fibrous mats composed of either random or aligned fibers reinforced with up to 20 wt % CNCs were successfully produced by two different electrospinning processes. Various concentrations of CNCs could be stably dispersed in PLA solution prior to fiber manufacture. The microstructure of produced fibrous mats, regardless of random or aligned orientation, was transformed from smooth to nanoporous surface by changing CNC loading levels.
View Article and Find Full Text PDFThe orthogonal design method was used to determine the optimum conditions for modifying poplar fibers through a high temperature and pressurized steam treatment for the subsequent preparation of wood fiber/high-density polyethylene (HDPE) composites. The extreme difference, variance, and significance analyses were performed to reveal the effect of the modification parameters on the mechanical properties of the prepared composites, and they yielded consistent results. The main findings indicated that the modification temperature most strongly affected the mechanical properties of the prepared composites, followed by the steam pressure.
View Article and Find Full Text PDFThe effects of alkaline copper quaternary (ACQ) and zinc borate (ZB) on the resistance of corn stalk fiber (CSF)-reinforced high-density polyethylene (HDPE) composites to biodegradation were examined. Both biocides could inhibit termites, mold fungi, and wood-decay fungi, even at high CSF formulations (i.e.
View Article and Find Full Text PDFA modified coaxial electrospinning process was used to prepare composite nanofibrous mats from a poly(methyl methacrylate) (PMMA) solution with the addition of different cellulose nanocrystals (CNCs) as the sheath fluid and polyacrylonitrile (PAN) solution as the core fluid. This study investigated the conductivity of the as-spun solutions that increased significantly with increasing CNCs addition, which favors forming uniform fibers. This study discussed the effect of different CNCs addition on the morphology, thermal behavior, and the multilevel structure of the coaxial electrospun PMMA + CNCs/PAN composite nanofibers.
View Article and Find Full Text PDFSurface modification and characterization of titanium dioxide (TiO₂) nanoparticles and their roles in thermal, mechanical, and accelerated aging behavior of foamed wheat straw fiber/polypropylene (PP) composites are investigated. To improve the dispersion of nanoparticles and increase the possible interactions between wheat straw fiber and the PP matrix, the surface of the TiO₂ nanoparticles was modified with ethenyltrimethoxy silane (A171), a silane coupling agent. The grafting of A171 on the TiO₂ nanoparticles' surface was characterized by Fourier transform infrared spectroscopy (FTIR).
View Article and Find Full Text PDFThe surfaces of poplar wood fibers were modified using high-temperature hot air (HTHA) treatment and silane coupling agent. The single factor test was then used to investigate the performances (e.g.
View Article and Find Full Text PDFRed pottery clay (RPC) was modified using a silane coupling agent, and the modified RPC (mRPC) was then used to enhance the performance of high-density polyethylene-based wood-plastic composites. The effect of the mRPC content on the performances of the composites was investigated through Fourier transform infrared spectrometry, differential mechanical analysis (DMA) and ultraviolet (UV)-accelerated aging tests. After adding the mRPC, a moisture adsorption hysteresis was observed.
View Article and Find Full Text PDFCore-shell structured hydrogels consisting of a flexible interpenetrating polymer network (IPN) core and a rigid semi-IPN shell were prepared through chemical crosslinking of polyvinyl alcohol (PVA) and sodium alginate (SA) with Ca(2+) and glutaraldehyde. Short cellulose nanofibers (CNFs) extracted from energycane bagasse were incorporated in the hydrogel. The shell was micro-porous and the core was macro-porous.
View Article and Find Full Text PDFCellulose I, cellulose II and cellulose I/II hybrid fibers were prepared from energycane bagasse using NaOH and NaClO2 treatments. The definitive defibrillation effect with an average width of 12±5μm was observed for the fibers treated with 20wt% NaOH for 10h and NaClO2 for 2h. The ribbon shaped cellulose I fibers were converted to a swollen state with a rougher surface by 20wt% NaOH treatment for 10h.
View Article and Find Full Text PDFMaterials (Basel)
January 2015
Temperature and relative humidity (RH) are two major external factors, which affect equilibrium moisture content (EMC) of wood-plastic composites (WPCs). In this study, the effect of different durability treatments on sorption and desorption isotherms of southern yellow pine (SYP)-high density polyethylene (HDPE) composites was investigated. All samples were equilibriumed at 20 °C and various RHs including 16%, 33%, 45%, 66%, 75%, 85%, 93%, and100%.
View Article and Find Full Text PDFCellulose nanoparticles (CNPs) were prepared from microcrystalline cellulose using two concentration levels of sulfuric acid (, 48 wt% and 64 wt% with produced CNPs designated as CNPs-48 and CNPs-64, respectively) followed by high-pressure homogenization. CNP-reinforced polymethylmethacrylate (PMMA) composite films at various CNP loadings were made using solvent exchange and solution casting methods. The ultraviolet-visible (UV-vis) transmittance spectra between 400 and 800 nm showed that CNPs-64/PMMA composites had a significantly higher optical transmittance than that of CNPs-48/PMMA.
View Article and Find Full Text PDFRegenerated cellulose nanoparticles (RCNs) including both elongated fiber and spherical structures were prepared from microcrystalline cellulose (MCC) and cotton using 1-butyl-3-methylimidazolium chloride followed by high-pressure homogenization. The crystalline structure of RCNs was cellulose II in contrast to the cellulose I form of the starting materials. Also, the RCNs have decreased crystallinity and crystallite size.
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