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In this study, hyperthermal hydrogen-induced cross-linking (HHIC) technology was applied to construct a dense cross-linking layer of antibacterial chitosan quaternary ammonium salt (HTCC) to PE surface through the selective cleavage of CH bonds and subsequent cross-linking of the resulting carbon radicals. Before HHIC treatment, UV-Ozone was used to activate PE surface to facilitate HTCC adsorption. FT-IR and XPS analyses proved the successful cross-linking between PE and HTCC. From AFM analysis, the prepared PE cross-linked HTCC film (PE-c-HTCC) showed the rougher surface with average roughness (Ra) of 9.16 nm. The water vapor permeability (WVP) and oxygen permeability (OP) values of the film were decreased by about 83 % and 97 %, respectively. Additionally, the film exhibited strong antibacterial properties against E. coli and S. aureus. In terms of these properties, the shelf life of fresh beef could be extended for 2 days after packing with the PE-c-HTCC film., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Selective fractionation of hemicelluloses is of great significance for realizing high-value application of hemicelluloses and comprehensive utilization of lignocellulosic biomass. Tetramethylammonium hydroxide (TMAH) solvent has been confirmed as a promising solvent to selectively fractionate hemicelluloses from holocellulose. Herein, TMAH solvent was adopted to pretreat poplar thermomechanical pulp (PTMP) for the selective fractionation of hemicelluloses and enhancement of enzymatic hydrolysis performance of residues. The maximal hemicelluloses yield (65.0 %) and excellent cellulose retention rate (93.3 %) were achieved after pretreatment by the 25 wt% TMAH solvent, while the delignification was only 33.9 %. The hemicelluloses fractions could be selectively fractionated with high molecular weights (109,800-118,500 g/mol), the contents of Klason lignin in them were low (3.2-5.9 %), and the dominating structure of them was 4-O-methylglucurono-β-D-xylan. Compared to the H 2 SO 4 and NaOH methods, the hemicelluloses fractionated by TMAH method exhibited higher yields, more complete structures and higher molecular weights. Furthermore, the crystalline structure of cellulose practically remained stable, and the highest yield of enzymatic hydrolysis glucose was 57.5 %, which was 3.3 times of that of PTMP. The fractionation effectiveness of TMAH solvent was not significantly reduced after repeatedly recycling. This work demonstrated TMAH solvent could selectively fractionate hemicelluloses from PTMP and efficiently promote sustainable poplar-based biorefinery., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier B.V. All rights reserved.)

High strength and self-healing properties of hydrogels are of great interest in tissue engineering and biomedical fields. In this paper, nanocomposite hydrogels were prepared by freeze-thaw cycle method via fabricating physical cross-links into chemical-crosslinked formed polymer network. The properties of nanocomposite hydrogels were characterized by FTIR, XRD, SEM, rheological analysis, swelling analysis and mechanical test. The results showed that the electrostatic interaction between CNC and QAX and the high amount of PVA (20 wt%) were favorable to improve the mechanical properties of nanocomposite hydrogels, in which the maximum compressive strength and elongation at break of nanocomposite hydrogels were 1.56 MPa and 771 %, respectively. Prepared hydrogels achieved self-healing without any external stimuli at room temperature with the help of hydrogen bonds and the entanglement of long polymer chains, the healing efficiency was 37.03 % within 48 h. These hydrogels with high strength and self-healing properties will offer new insights for xylan application., Competing Interests: Declaration of Competing Interest The authors declare no conflict interest., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

Woody materials are comprised of plant cell walls that contain a layered secondary cell wall composed of structural polymers of polysaccharides and lignin. Layer-by-layer (LbL) assembly process which relies on the assembly of oppositely charged molecules from aqueous solutions was used to build a freestanding composite film of isolated wood polymers of lignin and oxidized nanofibril cellulose (NFC). To facilitate the assembly of these negatively charged polymers, a positively charged polyelectrolyte, poly(diallyldimethylammomium chloride) (PDDA), was used as a linking layer to create this simplified model cell wall. The layered adsorption process was studied quantitatively using quartz crystal microbalance with dissipation monitoring (QCM-D) and ellipsometry. The results showed that layer mass/thickness per adsorbed layer increased as a function of total number of layers. The surface coverage of the adsorbed layers was studied with atomic force microscopy (AFM). Complete coverage of the surface with lignin in all the deposition cycles was found for the system, however, surface coverage by NFC increased with the number of layers. The adsorption process was carried out for 250 cycles (500 bilayers) on a cellulose acetate (CA) substrate. Transparent free-standing LBL assembled nanocomposite films were obtained when the CA substrate was later dissolved in acetone. Scanning electron microscopy (SEM) of the fractured cross-sections showed a lamellar structure, and the thickness per adsorption cycle (PDDA-Lignin-PDDA-NC) was estimated to be 17 nm for two different lignin types used in the study. The data indicates a film with highly controlled architecture where nanocellulose and lignin are spatially deposited on the nanoscale (a polymer-polymer nanocomposites), similar to what is observed in the native cell wall.

The surface-modification of paper substrates with functional layers is gaining increasing interest, both from academic and industrial research. In this case, the cellulosic paper (CP) surface was functionalized with zwitterionic poly-(3-dimethyl(methacryloyloxyethyl) ammoniumpropane sulfonate) (CP-g-P(DMAPS) via surface-initiated atom transfer radical polymerization (ATRP) technique for enhancing blood compatibility. An obvious increase in graft yield of the functional P(DMAPS) with polymerization time was observed. The new CP-g-P(DMAPS) produced was investigated for its hemocompatibility. The hemocompatibility studied including platelet and whole blood ceels adhesion tests, hemolysis assay, morphological changes of red blood cells (RBCs), coagulation time tests, and complement activation, platelet activation at the molecular level. Most assays had remarkable differences in the presence of the new zwitterionic CP, indicated the importance of the zwitterion for hemocompatibility of CP., (Copyright © 2014 Elsevier B.V. All rights reserved.)

To obtain effective adsorbent that can remove emerging organic pollutant of triclosan (TCS) in aquatic environment, different ester-containing Gemini surfactant-modified MMT (EMMT) were prepared under microwave irradiation. The whole process was rapid, uniform, easy and energy-efficient. The structures and morphology of EMMT were characterized by XRD, TEM, FT-IR, SEM and TGA. The results revealed that the saturated intercalation amount of this surfactant was 0.8 times to cation exchange capacity (CEC) of MMT, and there was electrostatic interaction between ester-containing Gemini surfactant and MMT. In addition, they bound in the ways of intercalation, intercalation-adsorption or adsorption, which relied on the dosage of the surfactant. The surface of EMMT was hydrophobic, rough and fluffy, which contributed to its strong adsorption capacity. The adsorption equilibrium data of EMMT for TCS were fitted to Langmuir and Freundlich isothermal adsorption model. The result showed that Langmuir isothermal adsorption model could describe the adsorption behavior better, the adsorption behavior of TCS on EMMT was confirmed to a surface monolayer adsorption, and notably the theoretical maximum adsorption capacity was up to 133 mg/g. Therefore, this work lays important foundation on developing effective and safe absorbent materials for the treatment of emerging organic pollutants., (Copyright © 2013 Elsevier Inc. All rights reserved.)

In this study, nanocrystalline cellulose (NCC) resulting from sulfuric acid hydrolysis of wood cellulose fiber, was rendered cationic by grafting with glycidyltrimethylammonium chloride (GTMAC). An optimization of the reaction parameters, such as water content, reactant mole ratio, and reaction media was performed. The presence of cationic GTMAC on the surface of NCC was confirmed by Fourier Transform Infrared Spectroscopy (FTIR). The cationically modified NCC was characterized by surface charge density, degree of substitution, ζ potential, and particle size. It was found that the cationic surface charge density of NCC can be increased by controlling the water content of the reaction system. Surface cationization of NCC led to an increase in the surface charge density over the un-modified NCC. The cationically modified NCC was well dispersed and stable in aqueous media due to enhanced cationic surface charge density. Transmission electron microscopy (TEM) images showed the improvement in state of dispersion of cationically modified NCC over the un-modified NCC. The optimum water content was found to be 36 wt% for aqueous based media and 0.5 water to DMSO volume ratio for aqueous-organic solvent reaction media. The increased surface charge density of NCC also delayed the onset of gelation in aqueous system., (Copyright © 2012 Elsevier Ltd. All rights reserved.)

An adaptive network based fuzzy inference system (ANFIS) model was employed to predict effluent chemical oxygen demand (COD(eff)) and ammonia nitrogen (NH(4)(+) (eff)) from an anaerobic/anoxic/oxic (A(2)/O) process, and meanwhile a self-adapted fuzzy c-means clustering algorithm was used to identify the model's architecture and optimize fuzzy rules. When constructing the model or predicting, the on-line monitoring parameters, namely hydraulic retention time (HRT), influent pH (pH), dissolved oxygen in the aerobic reactor (DO) and mixed-liquid return ratio (r), were adopted as the input variables. Compared with the artificial neural network (ANN) model whose weight vector was optimized by a real-code genetic algorithm (GA), the ANFIS presented better estimate performance. When predicting, the mean absolute percentage errors (MAPEs) of 1.8458% and 2.8984% for COD(eff) and NH(4)(+) (eff) could be achieved using ANFIS; the root mean square errors (RMSEs) for COD(eff) and NH(4)(+) (eff) were 1.6317 and 0.1291, respectively; the correlation coefficient (R) values of 0.9928 and 0.9951 for COD(eff) and NH(4)(+) (eff) could also be achieved. The results indicated that reasonable monitoring A(2)/O process performance, just using on-line monitoring parameters, has been achieved through the ANFIS.

This study demonstrates a headspace gas chromatographic(HS-GC) technique for the determination of residual epichlorohydrin (ECH) and generated 1,3-dichloro-2-propanol (DCP) in synthesis process of 3-chloro-2-hydroxypropyltrimethylammonium chloride (CHTAC). By a weight-based sampling method, coupled with significant dilution in 15.8% sodium sulfate and 0.1% silver nitrate mixed solution rapidly, the sample for HS-GC analysis is prepared. Based on the reaction stoichiometry, the conversion (R) of CHTAC during the synthesis process can be calculated from sampling weight and GC peak area. The results showed that the method has a good measurement precision (RSD<2.5%) and accuracy (recovery=101-104%) for the quantification of both ECH and DCP in the process samples. The present method is simple and accurate, which can be used for the efficient determination of the CHTAC conversion in the synthesis research., (Copyright © 2011 Elsevier B.V. All rights reserved.)