Effect of lignin on the thermal stability of cellulose nanofibrils produced from bagasse pulp Abstract In this work, the effects of lignin on the thermal stability of bagasse cellulose nanofibrils (CNFs) were investigated. The CNFs were prepared with different lignin content bagasse pulp using ultrafine grinding combined with high-pressure homogenization. Scanning electron microscopy, Fourier transform infrared spectroscopy, X-ray diffraction and thermogravimetric analysis were used to study the influence mechanisms of lignin content on the thermal stability of the CNFs. The thermal stability of cellulose was tested by thermogravimetric analyzer at different heating rates, and the activation energy of bagasse cellulose nanofibrils was calculated by Flynn-Wall-Ozawa method. The results showed that the average width of CNFs prepared by the mechanical method was approximately 20 nm. The higher the lignin contents in the CNFs, the lower the crystallinity and the better the thermal stability. The thermal decomposition activation energy of CNF fluctuates with the change of conversion rate. Under the same conversion rate, the higher the lignin contents in the CNFs, the larger the activation energy value. The average activation energies of NO-LCNF, L-LCNF, ML-LCNF, MH-LCNF, and H-LCNF were 208.14, 254.49, 412.95, 530.54 and 652.10 kJ/mol, respectively, during the conversion rate of 20% to 90%. The research results provide a theoretical basis for the pyrolysis mechanism and high value utilization of CNFs and have a profound impact on promoting the application and development of CNFs in emerging nanocomposites. Graphic abstract

Pickering emulsions stabilized by hydrophobically modified nanocellulose containing various structural characteristics Abstract Cellulose nanocrystals (CNCs) and cellulose nanofibrils (CNFs) extracted from renewable resources possess many attractive characteristics, making them ideal Pickering emulsion stabilizers. However, unmodified pristine CNCs with high surface charge density are not effective in stabilizing oil–water emulsions, thereby limiting their application as interfacial stabilizers. Grafting hydrophobic polymers onto CNCs enhanced their wettability by the oil phase, which reduced the interfacial tension. Thus, hydrophobic modification was performed by grafting cinnamoyl chloride or butyryl chloride to the surface of CNFs. The modified CNFs were further hydrolyzed for 1 or 2 h to produce nanocellulose of varying sizes and hydrophobicity, and they were effective Pickering emulsifiers. The effect of nanocellulose concentration, polarity of solvents, hydrophobicity, size and electrolyte on the characteristics of the Pickering emulsions were examined and elucidated. Graphic abstract

Correction to: Modification of hyperbranched hemicellulose polymer and its application in adsorbing acid dyes In the original publication of the article, the graphical abstract and Scheme 1(a) and Scheme 1(b) were published incorrectly.

Fabrication of Ag/AgCl/ZIF-8/TiO 2 decorated cotton fabric as a highly efficient photocatalyst for degradation of organic dyes under visible light Abstract In this work, a photocatalyst Ag/AgCl/ZIF-8/TiO2 was facilely assembled on the surface of cotton fabrics via a simple method to fabricate a visible-light photocatalyst composite. The resultant cotton fabric was comprehensively characterized by scanning electron microscopy, X-ray photoelectron spectroscopy, X-ray diffraction, and UV–vis diffuse reflection spectroscopy. The results showed that the Ag/AgCl/ZIF-8/TiO2 aggregations have successfully assembled on the surface of cotton fabric. Subsequently, Ag/AgCl/ZIF-8/TiO2 coated cotton fabric was employed as a visible-light photocatalytic material for degradation of organic dyes using methylene blue (MB) as a model. Owing to the synergistic effect of the Ag/AgCl/ZIF-8/TiO2 composite, the functional cotton fabric presented highly efficient photocatalytic degradation performance towards MB, the degradation of MB by Ag/AgCl/ZIF-8/TiO2 coated cotton fabric can reach to 98.5% within 105 min under visible light irradiation. Moreover, the first-order kinetic constant of photocatalytic degradation was 0.0332 min−1. Additionally, Ag/AgCl/ZIF-8/TiO2 coated cotton fabric exhibited acceptable cycle stability. The photocatalytic degradation capacity of MB still can maintain approximately 85% after three cycles. Therefore, Ag/AgCl/ZIF-8/TiO2coated cotton fabric can be viewed as a good material for dye wastewater treatment due to its good photocatalytic activity and acceptable cycle ability. Graphic abstract

Moisture adsorption in TEMPO-oxidized cellulose nanocrystal film at the nanogram level based on micro-FTIR spectroscopy Abstract The adsorbed water is known to have a significant influence on physical property of cellulose nanocrystal film. In order to characterize moisture adsorption of TEMPO oxidized cellulose nanocrystal film (TOCNF), a strategy for quantitative evaluation of moisture adsorption in TOCNF at the nanogram level is proposed here. In this approach, TOCNF spectra were in situ measured in a large range of relative humidity. Spectral analysis was applied to these measured spectra, and then moisture adsorption sites and spectrum ranges affected by moisture adsorption were identified. Based upon these confirmed spectrum ranges and moisture contents collected using dynamic vapor sorption apparatus, a micro-FTIR prediction model could be established using partial least squares regression. Afterwards, the established prediction model was used for acquiring moisture adsorption isotherm, and a good consistency between the forecasts and referential values was shown. It was confirmed this proposed strategy for quantitative evaluation of moisture adsorption in nanocellulose film at the nanogram level was effective.

One-step process for direct laser writing carbonization of NH 4 H 2 PO 4 treated cellulose paper and its use for facile fabrication of multifunctional force sensors with corrugated structures Abstract It is highly desired to be able to readily and robustly fabricate carbon patterns on cellulose paper (CellP) with complicated 3D structures, which would allow for cost-effectively developing a variety of resilient and stable paper-based sensors. Upon a pretreatment of CellP with NH4H2PO4, herein, we present a one-step direct laser writing carbonization (DLWc) method capable of in situ creating electrically conductive carbon features on the NH4H2PO4 treated CellP. With assistance of infrared spectroscopy, thermogravimetry and differential scanning calorimetry, the role of NH4H2PO4 in the pyrolysis/carbonization of cellulose paper to enhance the resultant carbon yield was investigated. The loadings of NH4H2PO4 in CellP and the laser processing conditions were studied for their effects on morphology/structure and electrical property of the carbon line features created by DLWc on the NH4H2PO4 treated CellP. Upon taking advantage of the unique mechanical characteristics of corrugated paper sheets, we further utilized the one-step DLWc process to fabricate disposable, lightweight, and low-cost paper-based sensors and demonstrated their use for sensing force, displacement, wind flow and finger-tapping position recognition. The one-step DLWc of CellP will lead a way towards large-scale, environmental-benign and cost-effective production of multifunctional paper-based sensors. Graphic abstract

Cellulose carbamate derived cellulose thin films: preparation, characterization and blending with cellulose xanthate Abstract Cellulose carbamate (CC) was employed as a water-soluble precursor in the manufacturing of cellulose based thin films using the spin coating technique. An intriguing observation was that during spin coating of CC from alkaline aqueous solutions, regeneration to cellulose was accomplished without the addition of any further chemicals. After rinsing, homogeneous thin films with tunable layer thickness in a range between 20 and 80 nm were obtained. Further, CC was blended with cellulose xanthate in different ratios (3:1, 1:1, 1:3) and after regeneration the properties of the resulting all-cellulose blend thin films were investigated. We could observe some slight indications of phase separation by means of atomic force microscopy. The layer thickness of the blend thin films was nearly independent of the ratio of the components, with values between 50 and 60 nm for the chosen conditions. The water uptake capability (80–90% relative to the film mass) determined by H2O/D2O exchange in a quartz crystal microbalance was independent of the blend ratio.

Triazine mediated covalent antibiotic grafting on cotton fabrics as a modular approach for developing antimicrobial barriers Abstract New antimicrobial textiles were prepared through direct chemical linkage of bioactive molecules eugenol and fluoroquinolone derivatives, onto the surface of cotton fabrics. The attachment through a triazine moiety minimizes the leaching of the antimicrobial molecule into the surroundings of the material. Bacterial efficacy against Staphylococcus aureus and Pseudomonas aeruginosa was studied. The treated textile with fluoroquinolone demonstrated bacteriostatic antimicrobial effects having a tendency to decrease the population of S. aureus in the planktonic form. A significant effect was also observed in the prevention of S. aureus biofilm formation and in its ability to kill bacteria within a preformed biofilm. Eugenol-modified fabric was also active in the process of eradicating preformed P. aeruginosa biofilms. Further, in vitro assays using human dermal fibroblast cells indicate no effects on cell proliferation and viability, and in vivo tests in a murine skin wound model showed no increase of IL-6 for full-thickness wounds that were in contact with the fabrics. Graphic abstract

Simulation of performance of fibrous filter media composed of cellulose and synthetic fibers Abstract Fibrous filter media with reticular support structure and tortuous pore channels have been widely used in filtration fields. Most of these filter media contain multiple types of fibers such as wood pulp fibers, glass fibers or synthetic fibers with a broad range of diameters to meet the requirements of filtration and strength performance. Some fibers in the filter media, e.g. cellulose fibers, have complex and irregular shapes such as hollow structure. It is necessary to generate a more realistic filter media model based on the actual properties of fibers. In this work, fibrous filter media with complex microstructure were investigated by simulation method. SEM (scanning electron microscope) and fiber analyzer were used to obtain the physical characteristics of fiber such as diameter, wall thickness, length Gaussian distributions, and cross-section shape. Based on these experimental data, a database containing several common fiber models was created. 3-D fibrous models corresponding to the real wet-laid binderless filter media were generated. Average pore size, permeability and collection efficiency simulations were carried out using the modules of the GeoDict code. The simulated results were close to the experimental data. With the work of this study, it was found that smaller diameter PET fibers in the filter media led to a lower average pore size, lower permeability and a better collection performance. When the diameter of PET fibers was < 5.54 μm, the change in fiber diameter has a great impact on the performance. When the diameter of PET fibers was larger than 12.40 μm, it has less effect on the performance. Graphic abstract

Syntheses of xylan stearate nanoparticles with loading function from by-products of viscose fiber mills Abstract A functional biopolymer was synthesized by introducing stearic acid (SA) to the backbone of xylan (X) obtained from viscose fiber mills. The SA–X derivatives were characterized by various tests for analysis of the functional properties. Effects on the esterification conditions including molar ratio, time and temperature were discussed, and the degree of substitution (DS) was in the range of 0.34–1.54. SA–X nanoparticles (SA–X NPs) were synthesized by dialysis, and the average particle size of the NPs was about 194 nm. Ketoprofen (KPF) was chosen as a hydrophobic model drug for the loading function evaluation, and the final encapsulation efficiency was about 64%. The KPF release profile in buffer standard solution with pH 11.0 and 2.0 were tested, and the final released amount were 43.6% and 53.8%, respectively. Thus, the fabrication of functional SA–X NPs provided a new way to improve the unreasonable application of factory biopolymer by-products.