CELLULOSE
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2019
·Vol. 26
·期 8
·5033-5049
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IF 3.917
Chen Yong,Ma Yijia,He Qingkun,Han Qiuxia,Zhang Qiang,Chen Qi
Abstract Cotton cellulose was modified with polysiloxane with dual antimicrobial groups of pyridinium and N -chloramine (N-Cl) to endorse enhanced synergistic biocidal ability. A new compound, 4-oxo- N -(pyridin-4-yl)pentanamide (OPPA), that contains precursors of both pyridinium and N -chloramine was synthesized via amidation of 4-oxopentanoic acid and 4-aminopyridine. The molecules of OPPA were connected to cotton cellulose using poly(methylhydrosiloxane) (PMHS) as linker through hydrosilylation reaction between some Si–H groups of PMHS and hydroxyl groups of cellulose and some other Si–H groups and ketone carbonyl groups of OPPA. The OPPA on cellulose was transformed into its biocidal counterpart after quaternization of the pyridine to pyridinium and chlorination of the amide N–H to N -chloramine. The synthetic procedures and modification results were characterized with Fourier-transform infrared spectroscopy, scanning electron microscopy (SEM), and X-ray photoelectron spectroscopy. The pyridinium/ N -chloramine polysiloxane layer on cellulose was estimated to be 77 nm by weight and provided powerful and synergistic antibacterial capacities against model species of Escherichia coli and Staphylococcus aureus . The stability of the polysiloxane modifier layer and the rechargeability of lost chlorine were promising under repeated washing, long-term storage, and UV irradiation. The presented pyridinium/ N -chloramine polysiloxane layer showed advantages over many of the current systems containing either cationic salt or N -chloramine due to the synergism. Graphical abstract
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POLYMER
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2019
·
IF 3.771
Junmei Zhang,Tao Liu,Zhenzhen Liu,Qingwen Wang
A high-strength polyvinyl alcohol (PVA) hydrogel was prepared via a facile photocrosslinked polymerization with cellulose nanofibrils (CNF) reinforcement. The mechanism of CNF reinforcement was studied systematically. The hydroxyl groups in the surface of CNF generate hydrogen bonds with the pendant hydroxyl of PVA chains, which promotes the interaction of already chemical crosslinked PVA chains and increases the crystallinity of the resultant PVA-MA/CNF hydrogel. By optimizing the CNF incorporation content to the PVA-MA/CNF hydrogel, a compressive fracture stress of 490 kPa was obtained, which is higher than that of previously reported nanocellulose reinforced PVA hydrogels. And more importantly, this gel exhibits excellent cyclic compressive performance. This work provides a novel method to improve the mechanical strength of PVA hydrogel which is beneficial for its application in tissue engineering field.
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CELLULOSE
·
2019
·Vol. 26
·期 12
·7451-7468
·
IF 3.917
Mo Yang,Yang Lijun,Hou Wei,Zou Tiantian,Huang Youyu,Zheng Xiaoling,Liao Ruijin
Abstract This study aims to decrease the dielectric constant of cellulose insulating paper by octa(aminophenyl)silsesquioxane (OAPS) grafting. OAPS was grafted onto the primary hydroxyl group of cellulose molecules via amino groups and epichlorohydrin. The dielectric constant and dielectric loss of insulating paper before and after modification were investigated. Relative to the unmodified paper, the dielectric constant of 15 wt% OAPS-grafted paper decreased from 5.27 to 4.28, and the dielectric loss decreased by 37.5% at 50 Hz. The movement and orientation polarization of the cellulose chains could be restricted due to the porous macromolecular structure and nano quantum interface effect produced by OAPS, thereby resulting in the reduction of cellulose polarizability. Moreover, the OAPS grafting modification does not degrade the other properties of cellulose insulation, i.e., its thermal stability, mechanical performance, fire-resistant properties, and electrical strength. OAPS grafting has promising potential application for preparing low dielectric constant insulating paper. Graphic abstract
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EUROPEAN POLYMER JOURNAL
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2019
·
IF 3.621
Yuchen Li,Xiaobang Hou,Yuanfeng Pan,Lidong Wang,Huining Xiao
The redox-responsive hydrogel as a carrier has been extensively explored for the application associated with drug delivery and tissue engineering due to its super capacity holding water and unique structure for controllable release. However, similar systems for adsorption and release of dyes have been seldom reported. In this work, a novel redox-responsive hydrogel with the size around 14.9 μm was synthesized towards the adsorption of organic dyes. Carboxymethyl cellulose nanocrystals was activated first; followed by reacting with l -cysteine to generate the amide bonds. The resulting disulfide cross-linked hydrogel can rapidly response to the external oxidizing or reducing stimuli to control the process of adsorption or release of dye, i.e., methylene blue (MB). As an efficient adsorbent, the maximum adsorption capacity of the hydrogel reached 756 mg g −1 at pH 11. The experimental data were also fitted with various kinetic and isotherm models. The results indicated that the pseudo-second-order kinetic and Freundlich isotherm models fitted the MB adsorption data well; whereas the release mechanism was better described by Fickian diffusion. Overall, the redox-responsive hydrogel developed in this work is promising for adsorption and enrichment of organic dyes; and its applications could be further broadened.
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INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
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2019
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IF 4.084
Tao Wang,Xiqing Liu,Donglai Han,Yuxuan Sun,Changchang Ma,Yang Liu,Pengwei Huo,Yongsheng Yan
In this work, a biofiber was used as the natural polymer carrier to design a BiVO 4 QDs/cellulose fiber composite for photocatalytic application. The biofiber was obtained from bamboo, which was green, abundant and short growth cycle in Asia. Naturally rich groups of biofiber provided many sites to absorb the Bi 3+ to form the uniform distribution for BiVO 4 QDs . Moreover, a series of results indicated the strong connection was formed between biofiber and BiVO 4 QDs, which could increase the stability and electron transfer . Therefore, the new composite photocatalyst exhibited better stability and effectively photocatalytic activity . Moreover, the possible mechanism of synthesis and photocatalytic were discussed, which provided insight for synthesizing photocatalytic based on biomaterials.
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SPECTROCHIMICA ACTA PART A-MOLECULAR AND BIOMOLECULAR SPECTROSCOPY
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2019
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IF 2.931
Sijia Liu,Rongkai Cui,Yibo Ma,Qian Yu,Akash Kannegulla,Bo Wu,Hongtao Fan,Alan X. Wang,Xianming Kong
Flexible plasmonic Surface-enhanced Raman scattering (SERS) substrates were fabricated using cellulose textile fibers, in which the textile fibers were recycled from waste paper in an eco-friendly way. The Glycidyltrimethylammonium chloride (GTAC) with positive charges was grafted onto the surface of the cellulose textile fibers through cationization. Plasmonic silver nanoparticles (Ag NPs) with negative charges were decorated onto the cellulose textile fibers via electrostatic interactions . After cationization, the variation range of the diameter of the cellulose textile fibers was significantly increased because part of the cellulose was dissolved under alkaline condition, leading to more ‘hot spots’ for SERS during the shrinking process. The cellulose textile fiber-Ag NPs nanocomposite was employed for monitoring bisphenol A (BPA) in water and soft drink by SERS and the sensitivity of BPA detection achieved 50 ppb. The recovery values of BPA in soda water samples were from 96% to 105%. These results illustrate that the cellulose textile fiber-Ag NPs nanocomposite can be used as flexible, high sensitivity SERS substrates for detecting harmful ingredients in food or environment.
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CARBOHYDRATE POLYMERS
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2019
·
IF 6.044
Limei Ma,Zijian Xu,Xiangzhi Zhang,Jinyou Lin,Renzhong Tai
Cellulose nanofibrils (CNF) is a suitable functional material as its lightweight, huge availability and biodegradable advantages. A direct-evaporation method was employed to prepare the CNF nanopapers with or without Fe 3 O 4 and TiO 2 nanoparticles (NPs) in the form of films, which is more facile and efficient in comparison with the methods of vacuum-filtration and cast drying. A combination of three-dimensional (3D) focal stacks and dual-energy imaging method was firstly used to characterize the CNF nanopapers embedded with Fe 3 O 4 and TiO 2 NPs, where the locations of the NPs can be clearly and exactly distinguished. Furthermore, the thickness, transparency, magnetism and tensile properties of the CNF nanopapers were characterized. This work shows a facile method for the preparation of CNF nanopapers with or without addition. More importantly, the combination of focal stacks and dual-energy imaging method offers a superior means of characterizing the spatial structures and 3D elemental visualization.
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ACS Applied Materials & Interfaces
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2018
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IF 8.097
Aijaz Ahmed Babar,Dongyang Miao,Nadir Ali,Jing Zhao,Xianfeng Wang,Jianyong Yu,Bin Ding
Textiles with excellent moisture transport characteristics play key role in regulating comfort of the body, and use of color in textiles helps in developing aesthetically pleasing apparels. Herein, we report an aesthetically pleasing and breathable dual-layer cellulose acetate (CA) based nanofibrous membranes with exceptional directional moisture transport performance. The outer layer was synthesized by subjecting CA nanofibers to hydrolysis and reactive dyeing processes, which converted moderately hydrophobic CA nanofibers into uniformly colored superhydrophilic CA nanofibers with an excellent wettability. In addition to excellent wettability and superhydrophilic nature, dyed CA (DCA) nanofibers also offered high color yield and dye fixation as well as considerable colorfastness performance against washing and light, thus, were used as the outer layer. However, pristine CA nanofibers were chosen as the inner layer for their moderate hydrophobicity. The subsequent CA/DCA nanofiber membrane produced a high wettability gradient, which facilitated directional moisture transport from CA to DCA layers. The resultant dual-layer nanofiber membranes offered a high color yield of 16.33 with ∼82% dye fixation, excellent accumulative one-way transport capacity (919%), remarkable overall moisture management capacity (0.89), and reasonably high water vapor transport rate (12.11 kg d–1 m–2), suggesting them to be a potential substrate for fast sweat-release applications.
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INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
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2018
·
IF 3.909
Xichan He,Xialian Fan,Wenpo Feng,Yifei Chen,Ting Guo,Fang Wang,Jie Liu,Keyong Tang
In this study, the composite of Collagen-Hydroxyapitite (COL-HA) with microfibrillated cellulose (MFC) was developed as a new bone substitute material. COL-HA was prepared by in-situ method and modified by dehydrothermal treatment. Microfibrillated cellulose (MFC), a nature polysaccharide with plenty of hydroxyl groups, was incorporated into COL-HA composites to improve the properties. The novel COL-HA-MFC scaffold with different ratios of COL-HA and MFC were fabricated by cold isostatic pressing technique and freeze-drying technology. During the forming process, a three-dimensional bone-like structure was shaped in hybrid scaffolds. The microstructural transitions of COL-HA-MFC composites were examined by Fourier transform infrared spectroscope (FTIR), Ultraviolet-visible spectrophotometer (UV), and X-ray diffraction (XRD), which indicated that HA deposited on collagen molecules and MFC bonded with COL-HA. Hydrophilicity, swelling property, mechanical property, and degradability of COL-HA-MFC composites were investigated. Biological properties, such as cytotoxicity and hemolysis, were also studied. The results showed a good swelling capacity for the scaffolds, keeping their original shapes after swelling. The compression strength and degradability of the scaffold materials could be regulated by the MFC content. The compression strength of COL-HA-MFC composite scaffords increased to 20–40 MPa, closing to that of the nature bone (1–200 MPa). The obtained scaffolds are good in biocompatibility with high level of cell growth rate (>70%) and suitable hemolysis rate (≦5%). The work might provide an efficient and alternative approach for collagen-based biomaterials with necessary properties. The COL-HA-MFC composite scaffold showed a potential application in bone tissue engineering.
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ACS Sustainable Chemistry & Engineering
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2018
·
IF 6.14
Qing Wang,Guangxue Chen,Zhaohui Yu,Xinping Ouyang,Junfei Tian,Mingguang Yu
Photoluminescent materials have been applied worldwide in anticounterfeiting and security fields due to their unique performance of better security, easy identification, and difficulty of duplication. Herein, a facile, green, and low-cost strategy to fabricate biomass-based composites composed of lanthanide rare earth ions-doped nanocrystals and cellulose fibers for anticounterfeiting application was presented. The photoluminescent materials were prepared via in situ chemical deposition of rare earth ions onto bleached hardwood pulp cellulose fibers (bhpFibers) surface using polyvinylpyrrolidone (PVP) as coupling agent, forming bhpFibers-PVP@LaF3:Eu3+ composites. The bhpFibers-PVP@LaF3:Eu3+ composites showed excellent luminescence, and their fluorescence intensity can be simply controlled by varying the addition of the right amount of lanthanum (La3+) and europium (Eu3+) ions in aqueous medium. Furthermore, the composites have been used as blocks to form photoluminescence paper via a suction filtration procedure. The as-prepared paper possessed excellent luminescence, high flexibility, well writable and printable properties. Moreover, the whole procedure was carried out in a mild environment without toxic reagents. This simple, green, and low-cost technology presented has advantages of wholesale production of biomass-based photoluminescent materials for anticounterfeiting applications.
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CARBOHYDRATE POLYMERS
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2018
·
IF 5.158
Shaojie Liu,Huazhe Liang,Tingting Sun,Desheng Yang,Meng Cao
Polyamidoamine (PAMAM) dendrimers of G1.0 and 2.0 were synthesized by the repeated Michael addition and ester aminolysis of ethylenediamine and methyl acrylate. Through the reductive amination reaction of primary amines in PAMAM and carbonyl groups in 4-oxo-2,2,6,6-tetramethylpiperidine-1-oxyl (4-oxo-TEMPO), the water-soluble PAMAM immobilized TEMPO (PAMAM-TEMPO) was successfully prepared. The obtained PAMAM-TEMPO was characterized by Fourier transform infrared spectroscopy (FT-IR) and ultraviolet-visible spectrophotometer (UV–vis). PAMAM-TEMPO was used as catalyst instead of free TEMPO for selective catalytic oxidation of primary hydroxyl groups in cellulose with water as reaction medium. The results showed that the catalytic performance of G1.0 PAMAM-TEMPO with 28.8% TEMPO loading was equivalent to free TEMPO. After salting out the supernatant of oxidation mixture, PAMAM-TEMPO was recovered by extraction with N ,N- dimethylformamide and reused for further oxidation cycles. No significant reduction in catalytic performance was found after 4 oxidation cycles. The recovery of PAMAM-TEMPO after each cycle was about 90%. By sonication of oxidized cellulose obtained with G1.0 PAMAM-TEMPO as catalyst, the individualized cellulose nanofibers with approximately 10 nm in diameter were successfully prepared. This is the first report on the use of immobilized TEMPO catalysts comparable to the performance of free TEMPO to oxidize cellulose in water.
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Polymers
·
2018
·Vol. 10
·期 10
·1168
·
IF 2.935
Xuehua Liu,Rue Yang,Mingcong Xu,Chunhui Ma,Wei Li,Yu Yin,Qiongtao Huang,Yiqiang Wu,Jian Li,Shouxin Liu
In this work, we applied a fast and simple method to synthesize cellulose nanocrystal (CNC) aerogels, via a hydrothermal strategy followed by freeze drying. The characteristics and morphology of the obtained CNC-g-AA aerogels were affected by the hydrothermal treatment time, volume of added AA (acrylic acid), and the mass fraction of the CNCs. The formation mechanism of the aerogels involved free radical graft copolymerization of AA and CNCs with the cross-linkerN,N′-methylene bis(acrylamide) (MBA) during the hydrothermal process. The swelling ratio of the CNC-g-AA aerogels was as high as 495:1, which is considerably greater than that of other polysaccharide-g-AA aerogels systems. Moreover, the CNC-g-AA aerogels exhibited an excellent methyl blue (MB) adsorption capacity and the ability to undergo rapid desorption/regeneration. The maximum adsorption capacity of the CNC-g-AA aerogels for MB was greater than 400 mg/g. Excellent regeneration performance further indicates the promise of our CNC-g-AA aerogels as an adsorbent for applications in environmental remediation.Keywords:cellulose nanocrystals;hydrothermal;aerogels;superabsorbent
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