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The application of silver nanoparticles (AgNPs) in antibacterial materials, glucose detection, etc., is of broad interest for researchers around the world. Nanocellulose with many excellent properties can be used as a carrier and stabilizer to assist in the synthesis of AgNPs. In this study, cellulose nanofibrils (CNFs) and cellulose nanocrystals (CNCs) were used to assist in the synthesis of AgNPs under the reduction of glucose and detection of glucose concentration under different conditions. Transmission electron microscopy (TEM) analysis showed that the AgNPs in the nanocellulose-AgNPs (NC-AgNPs) system were roughly spherical and randomly distributed on the nanocellulose. In the whole reaction system, when the concentration of nanocellulose is 0.11 mg/mL, the concentration of silver ammonia solution is 0.6 mM, and the mixing time is 2.5 h, according to the UV-Vis analysis, the absorbance of CNF-AgNPs at 425 nm exhibited a good linear relationship (R2 = 0.9945) with the glucose concentration range (5–50 μM), while the absorbance of CNC-AgNPs at 420 nm showed a good linear relationship (R2 = 0.9956) with the glucose concentration range (5–35 μM). The synthesis of NC-AgNPs can be further developed into a sensor with higher sensitivity and higher stability for detecting glucose concentration and a material with antibacterial effects.

The kernel least mean square (KLMS) using the stochastic gradient descent (SGD) method has been proposed successfully in a Gaussian noise. However, KLMS suffers from performance degradation in terms of convergence rate and filtering accuracy. To this end, an adaptive gradient (Adagrad) optimization algorithm is used to find the solution to the least mean square of error, and the Nystrom method is applied into KLMS to reduce its computational and spatial complexity, generating an online Nystrom kernel Adagrad least mean square (NKALMS) algorithm. To further improve the filtering accuracy of NKALMS, another online Nystrom kernel Adagrad least mean square algorithm using k-means sampling (NKALMS-K) is developed in this paper. Monte Carlo simulations on time series prediction demonstrate that the NKALMS-K algorithm outperforms KLMS and its extensions in the presence of Gaussian noise from the aspects of accuracy and computational efficiency.

To improve the physical strength of regenerated cellulose fibers, cellulose dissolution was analyzed with a conductor-like screening model for real solvents in which 1-allyl-3-methylimidazolium chloride (AMIMCl) worked only as a hydrogen bond acceptor while dissolving the cellulose. This process could be promoted by the addition of urea, glycerol, and choline chloride. The dissolution and regeneration of cellulose was achieved through dry-jet and wet-spinning. The results demonstrated that the addition of hydrogen bond donors and acceptors either on their own or in combination can enhance the tensile strength, but their effects on the crystallinity of the regenerated fibers were quite limited. Compared with the regenerated fibers without any additives, the tensile strength was improved from 54.43 MPa to 139.62 MPa after introducing the choline chloride and glycerol, while related the crystallinity was only changed from 60.06% to 62.97%. By contrast, a more compact structure and fewer pores on the fiber surface were identified in samples with additives along with well-preserved cellulose frameworks. Besides, it should be noted that an optimization in the overall thermal stability was obtained in samples with additives. The significant effect of regenerated cellulose with the addition of glycerol was attributed to the reduction of cellulose damage by slowing down the dissolution and cross-linking in the cellulose viscose. The enhancement of the physical strength of regenerated cellulose fiber can be realized by the appropriate adjustment of the hydrogen bond distribution in the ionic liquid system with additives.

Four ionic liquids (ILs) were blended with polysulfone (PSF) to produce functional dense polymer-supported IL membranes (DPSILMs). The main aim was to investigate the applicability of the DPSILMs in industrial gas processing applications for high-pressure CO2 separation from N2 and CH4 streams with less or no IL loss. The DPSILMs showed a clear chemical and physical change in the PSF structure and a good IL distribution in PSF. CO2/N2 and CO2/CH4 binary mixtures (5�mol% CO2) were used. The highest CO2/N2 selectivities were 36 for PSF-0.5�wt% [DIP-C4mim][NTf2] and PSF-25�wt% [N4441][formate], and 29 and 21 for PSF-0.5�wt% [C4mim][NTf2] and PSF-50�wt% [P4441][formate], respectively. The highest CO2/CH4 selectivities were 70, 63, 47, and 32 for PSF-2.5�wt% [C4mim][NTf2], PSF-2.5�wt% [DIP-C4mim][NTf2], PSF-0.5�wt% [N4441][formate], and PSF-5 wt% [P4441][formate], respectively. Another system was used to measure the permeability of each gas for plotting on the Robeson's upper bound. The DPSILMs afforded satisfying results and behave as well or better than reported PSF blends. DPSILMs with 5�wt% [P4441][formate] and [N4441][formate] showed ?30% and 20% IL loss, respectively, at 10�bar after 12�h, while no loss was observed for [DIP-C4mim][NTf2] and [C4mim][NTf2]. This publication was made possible by NPRP Grant # [ 09-739-2-284 ] from the Qatar National Research Fund (a member of Qatar Foundation). The statements made herein are solely the responsibility of the authors. Scopus

Content: The application of split leather is an important issue in leather industry as most of them was not properly treated and wasted. In this study the application of choline chloride (ChCl), urea (U) and corresponding deep eutectic solvents (DES) on the modification of thermal stability and mechanical strength of mink split leather was investigated. TGA and DSC results indicated DES treatment enhanced thermal stability of split leather, and ChCl treatment reduced the stability. While, U treatment provided a kinetic inhibition during the thermal-decomposition. In terms of the mechanical strength, both ChCl and U treatment reduced burst intensity and extended height. While, after DES treatment the burst intensity and extended height increased significantly. In terms of the dosage, 7% DES provided best performance. Results mentioned above illustrated that DES formed by simply mixing ChCl and U provided strong interaction with fiber, enhanced the crosslinks. A hypothesis of [Ch(Urea)]+[Cl(Urea)]- type structure was proposed, as it enabled DES forming strong hydrogen bonds with functional groups on leather fiber, enhancing the crosslinks and therefore improving the thermal stability and mechanical strength. The DES treatment on leather fibers improved their overall performance and thereby broaden their applications. Take-Away: 1. DES obtained by mixing ChCl and urea presented very different effect in leather treatment, as the thermal stability and physical strength of leather improved significantly after the DES treatment. 2. A hypothesis of [Ch(Urea)]+[Cl(Urea)]- type structure was proposed, illustrating a formation of strong hydrogen bonds between DES and functional groups on leather fiber. This enhances the crosslinks and therefore improves the thermal and mechanical strength of leather.