CARBOHYDRATE POLYMERS
·
2012
·
IF 3.628
Yanzhu Guo,Xiaohui Wang,Zuguang Shen,Xuancai Shu,Runcang Sun
Self-associating cellulose- graft -poly( ɛ -caprolactone) (cellulose- g -PCL) copolymers were successfully synthesized via homogeneous ring-opening polymerization (ROP) of ɛ -CL onto softwood dissolved pulp substrate in ionic liquid 1-N-butyl-3-methylimidazolium chloride ([Bmim]Cl). An organic catalyst N,N-dimethylamino-4-pyridine (DMAP) was compared with the traditional metal-based catalyst (Sn(Oct) 2 ) as the catalyst of the reaction, and exhibited higher catalytic activity. By controlling the cellulose: ɛ -CL feed ratio and reaction temperature, the molecular architecture of the copolymers can be altered, as evidenced by FT-IR, 1 H NMR, 13 C NMR, TGA and XRD. The self-assembly behavior of the copolymers in water was investigated and characterized using fluorescence probe, dynamic light scattering (DLS) and SEM. The results showed that the cellulose- g -PCL copolymers could form nanosized micelles (approximately 20–100 nm) in water, and the micelle size and critical micelle concentration (CMC) can be controlled by varying the grafting ratio of PCL. These cellulose-based nanomicelles are expected to be useful in broad application fields.
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DOI
高影响因子
ACS Omega
·
2021
·
IF 3.512
Yaqi Gong,Shabbir Mohd,Simei Wu,Shilin Liu,Ying Pei,Xiaogang Luo
Functional modified cellulose microsphere (CMs) materials exhibit great application potential in drug various fields. Here, we designed pH-responsive carboxylated cellulose microspheres (CCMs) by the citric/hydrochloric acid hydrolysis method to enhance oral bioavailability of insulin by a green route. The CMs were high purity cellulose that dissolved and regenerated from a green solvent by the green sol–gel method. The prepared microspheres were characterized by spectroscopic techniques, such as field emission scanning electron microscopy (FE-SEM), Fourier transform infrared spectrum (FT-IR), X-ray diffraction (XPS), etc. The spherical porous structure and carboxylation of cellulose were confirmed by FESEM and FT-IR, respectively. Insulin was loaded into the CCMs by electrostatic interactions, and the insulin release was controlled through ionization of carboxyl groups and proton balance. In vitro insulin release profiles demonstrated the suppression of insulin release in artificial gastric fluid (AGF), while a significant increase at artificial intestinal fluid (AIF) was observed. The insulin release profile was fitted in Korsmeyer–Peppas kinetic model, and insulin release was governed by the Fickian diffusion mechanism. The stability of the secondary structure of insulin was studied by dichroism circular. Excellent biocompatibility and no cytotoxicity of designed CCMs cast them as a potential oral insulin carrier.
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高影响因子
NANOTECHNOLOGY
·
2021
·Vol. 32
·期 49
·495708
·
IF 3.874
Lu Tang,Jing Liao,Hongjie Dai,Yushan Liu,Huihua Huang
Pineapple, as a world-famous tropical fruit, is also prone to produce by-products rich in cellulose. In this study, different sections of pineapple, including pineapple core (PC), pineapple pulp (PPu), pineapple leaf (PL) and pineapple peel (PPe) were used for production of pineapple cellulose nanocrystals (PCNCs) by sulfuric acid hydrolysis. The crystallinity of PCNCs from PC, PPu, PL and PPe were 57.81%, 55.68%, 59.19% and 53.58%, respectively, and the thermal stability of PCNCs in order was PC > PL > PPe > PPu. The prepared PCNCs from PC, PPu, PL and PPe were needle like structure at the average aspect ratios of 14.2, 5.6, 5.5, and 14.8, respectively. Additionally, the differences in the structure and properties of PCNCs affected the stability of the prepared Pickering emulsions, which ranked as PPu > PPe > PL > PC. The Pickering emulsions stabilized by PCNCs prepared from PPu could be stored stably for more than 50 d. These results show the differences of PCNCs from four sections of pineapple, and provide isolated raw material selection for the further application of PCNCs.
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高影响因子
Desalination and Water Treatment
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2024
·
IF 1
Yue Yang,Xingan Wu,Xueru Sheng,Jian Zhang,Peng Lu,Na Li,Qingwei Ping
Novel modified cellulose/biochar beads (MCBBs) were prepared and utilized as support to immobilize laccase to remove phenol from an aqueous system. Nano CaCO 3 was introduced in CBBs prepared stage to produce proper pore structure by reacting with HCl solution. CBBs were then modified with maleic anhydride to introduce carboxyl groups. By adsorption and covalent bonding, the laccase was immobilized on the MCBBs. The pH, laccase concentration, and contact time were chosen as the main parameters in the laccase immobilizing experiment and the effects of these parameters on immobilization rates and recovered activity were studied. The results demonstrated that the best conditions are: pH 4.0, concentration 8 g L –1 , and contact time 6 h. The thermal and operational stability of the immobilized laccase has attended a good performance under these conditions. The immobilized laccase was used to degrade phenol in an aqueous system and 40.97% removal was achieved after 72 h. The results suggest that as a new green material, MCBBs can be good support for immobilizing laccase. This technique has potential advantages in removing phenol from wastewater.
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高影响因子
CELLULOSE
·
2018
·Vol. 25
·期 12
·7065-7078
·
IF 3.809
Liu Xiuyu,Jiang Yan,Qin Chengrong,Yang Shuang,Song Xueping,Wang Shuangfei,Li Kecheng
Abstract Bagasse fibers are smaller and have more hemicellulose than softwood fibers, which is expected to require less mechanical energy in cellulose nanofiber production as small size and hemicellulose benefit the disintegration of fibrils during a mechanical process. Both bagasse fibers and softwood fibers were used in this investigation for producing nanofibers with enzyme pretreatment followed by mechanical grinding. Results showed that nanofibers from bagasse had more uniform diameters about 9 nm, and the films made from them were more transparent. Grinding energy consumption of bagasse fibers was significantly lower than softwood, by 7.31%, and enzyme pretreatment further improved the energy efficiency, by 59.71%, and the yield of nanofibers, by 30.57%. The mechanical strength and thermal stability of nanofiber films from bagasse fibers were similar with that from softwood fibers. The results support the idea that bagasse, a waste or byproduct from sugar industry can be a promising alternative for nanofiber production.
Graphical abstract
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高影响因子
CRYSTENGCOMM
·
2012
·Vol. 14
·期 14
·4786-4793
·
IF 3.842
Qianming Wang,Zhengyang Zhang,Yuhui Zheng,Weisheng Cai,Yifei Yu
A systematic study of the preparation of lanthanide (Eu3+, Tb3+, Sm3+ and Dy3+) phosphors was carried out and luminescent materials (red, green, orange-red and blue-yellow) were successfully achieved at low temperature (70 °C) in 45 min, using simultaneous supersonic and microwave irradiation. Scanning and transmission electron microscopic images indicate that one-dimensional nanorods with diameters of 10–20 nm and lengths of up to 200 nm were formed. The phosphors were entrapped in cellulose gels and the corresponding hydrogels were also strongly emissive.
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DOI
高影响因子
FOOD HYDROCOLLOIDS
·
2020
·
IF 7.053
Xiangwei Zhu,Jianjun Chen,Yuxi Hu,Ni Zhang,Yuqing Fu,Xiaoqiang Chen
Carboxymethyl cellulose (CMC) is an economical and easily available cellulose derivative that ionizes in water and is used in several charge-related interfacial applications. However, compared with other chemically functionalized cellulose derivatives, such as cellulose nanocrystals, the development of CMC-based (CMC as the major ingredient) O/W emulsions remains unexplored. In this study, we synthesized a CMC and quaternized chitosan (QCS) complex for the preparation of Pickering emulsions . Partially protonated CMC was complexed with QCS, followed by neutralization at pH 7 to obtain the CMC/QCS (CQ) particles. The prepared CQ-stabilized emulsion showed a gel-like rheological behavior and exhibited emulsion stability against several environmental stresses, including pH, salt, temperature, and long-term storage. The curcumin was then encapsulated in the CQ-stabilized emulsion and displayed a reduced degradation rate. This study provides a new route for the development of a Pickering emulsion delivery system with improved stability, sustainability and reduced complexity.
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高影响因子
CELLULOSE
·
2020
·Vol. 27
·期 6
·3277-3286
·
IF 4.21
Hou Ting,Shu Lian,Guo Kechun,Zhang Xiong-Fei,Zhou Shuai,He Ming,Yao Jianfeng
Cellulose-based mixed-matrix membranes containing polyethylenimine-modified graphene oxide (PEI-GO) and Zn 2+ ions were fabricated and used for gas separation.
The incorporation of PEI-GO effectively hinders the crystallinity of regenerated cellulose, and PEI-GO was compatible with cellulose matrix and uniformly distributed within the matrix. X-ray photoelectron spectrum revealed the amino group on GO surface can effectively coordinate with Zn 2+ ions in the membrane. The Zn 2+ ions content in the membranes increased when increasing the PEI-GO addition.
The optimum separation performance was achieved over the membrane with 17 wt‰ PEI-GO (RC-17) wiht the highest zinc content of 24.2 wt%. The corresponding permeability of CO 2 is as high as 268.9 Barrer, and the CO 2 /N 2 and CO 2 /CH 4 ideal selectivities could reach 48.9 and 57.4, respectively. The enhancement of CO 2 transportation was attributed to both the regulated microstructure of cellulose membrane by PEI-GO and the π-complexation mechanism of Zn 2+ ions with CO 2 molecules. The prepared membranes would have a highly potential use in the field of CO 2 separation.
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高影响因子
JOURNAL OF MATERIALS SCIENCE
·
2016
·Vol. 51
·期 19
·8888-8899
·
IF 2.302
Luo Qiyun,Li Yuqi,Pan Lulu,Song Laifu,yang Jin,Wu Lingyan,Lu Shaorong
Interface design plays a crucial role in developing superior mechanical performance of nature fibers/polymer composites (NPC). Herein, microcrystalline cellulose fibers (MCFs), extracted from sisal fibers, were modified by function end-group hyperbranched liquid crystals (HLP) with respect to improve the wettability and interactions between the MCFs and epoxy resin (EP). The HLP that modified MCFs (HLP-MCFs) were studied by Fourier transform infrared spectroscopy, scanning electron microscopy, X-ray photoelectron spectroscopy, X-ray diffraction, and polarizing microscope. The results showed that the MCFs can be successfully modified by the HLP, which would provide strong MCFs/matrix interfacial adhesion. Therefore, the addition of HLP-MCFs was found to produce significant enhancements in the mechanical and thermal properties of EP. In particular, at 1.0 wt% filler loading, the flexural strength, tensile strength, impact strength, and flexural modulus of the HLP-MCFs/EP composites increased by 60, 69, 130, and 192 %, respectively, as well as the glass transition temperature increased by a notable 42.9 °C. It is anticipated that our current work would inform ongoing efforts to exploit more efficient method to overcome the poor nature fiber/polymer adhesion in the interface region and broad implications for the development of the NPC for engineering applications.
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高影响因子
Frontiers of Materials Science
·
2018
·Vol. 12
·期 2
·118-128
·
IF 1.478
Wang Qian,Meng Guihua,Wu Jianning,Wang Yixi,Liu Zhiyong,Guo Xuhong
We fabricated pH and light dual-responsive adsorption materials which could induce the transition of surface wettability between hydrophobicity and hydrophilicity by using ATRP. The structure and morphology of adsorption materials were confirmed by ATR-FTIR, XPS, TGA and SEM. It showed that the modified cellulose (CE)-based foam was hydrophobic, which can adsorb a range of oils and organic solvents in water under pH = 7.0 or visible light irradiation ( λ > 500 nm). Meanwhile, the wettability of robust CE-based foam can convert hydrophobicity into hydrophilicity and underwater oleophobicity under pH = 3.0 or UV irradiation ( λ = 365 nm), giving rise to release oils and organic solvents. Most important of all, the adsorption and desorption processes of the modified CE-based foam could be switched by external stimuli. Furthermore, the modified CE-based foam was not damaged and still retained original performance after reversible cycle repeated for many times with variation of surface wettability. In short, it indicates that CE-based foam materials with switchable surface wettability are new responsive absorbent materials and have owned potential application in the treatment of oil recovery.
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高影响因子
CARBOHYDRATE POLYMERS
·
2020
·
IF 7.182
Hongbo Suo,Lili Xu,Yu Xue,Xiang Qiu,He Huang,Yi Hu
In this work, ionic liquids-modified magnetic carboxymethyl cellulose nanoparticles (IL-MCMC) were prepared and used as supports for enzyme immobilization. The specific activity of immobilized lipase PPL-IL-MCMC was 1.43 and 2.81 folds higher than that of free PPL and PPL-MCMC, respectively. Water contact angle analysis indicated that the introduction of ionic liquids increased the hydrophobicity of supports, which in tune induced the lid-opening of lipase, allowing its active sites to become more accessible. In addition, the affinity between lipase and substrate immobilized on the prepared supports was enhanced. The same method was also applied to analyze immobilize penicillin G acylase (PGA) to further investigate the general applicability of the method. The results showed that the immobilized PGA exhibited higher stability than many other reported PGAs. The developed composites may be utilized as excellent supports for enzyme immobilization in industrial application.
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高影响因子
CELLULOSE
·
2017
·Vol. 24
·期 10
·4189-4203
·
IF 3.417
Zhang Xiuqiang,Zhang Jinlong,Dong Lili,Ren Suxia,Wu Qinglin,Lei Tingzhou
We report a series of thermoresponsive cellulose nanocrystals (CNCs) decorated with poly(poly(ethylene glycol) methylacrylate) copolymers (poly(PEGMA)- g -CNCs) synthesized by surface initiated-atom transfer radical polymerization (SI-ATRP). The chemical structures and surface morphologies were subsequently confirmed by FT-IR, XPS, and AFM measurements. With regard to thermally responsive behavior, poly(PEGMA)- g -CNCs show tunable lower critical solution temperature (LCST) values in the range of 34–66 °C by varying the feeding ratios of comonomers. The reversible morphological transformation from individual nano-rod structures to larger globule aggregates was further verified by AFM during the LCST transition. These functionalized CNCs have potential as smart film filters and biosensors.
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高影响因子
危险品化学品经营许可证（带存储）