CELLULOSE
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2025
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IF 4.8
Gunawan Ivana,Zhang Yue,Wang Huijie,Kou Mengtian,Wang Chao,Zhang Yumei
Pulp pre-treatment acts as a preliminary treatment in the lyocell process, allowing aqueous NMMO solvent molecules to penetrate the wood fiber structure. The present paper first determines cellulose’s pre-swelling, swelling, and dissolution phenomena in NMMO aqueous solutions of different concentrations and temperatures. It was found that instead of “ pre-swelling ” and “ dissolution ”, the “ swelling ” action during pre-treatment develops the most suitable interaction between wood pulp fiber and solvent. Higher concentrations of NMMO aqueous solutions (70–80%) do not contain enough water and that limits the uniform wetting of the pulp, while a lower NMMO concentration (50%) is not able to fully establish the hydrogen bonding interaction between cellulose and NMMO. The pre-treatment of cellulose pulp using 60% NMMO aqueous solution at 65 °C can ensure that NMMO itself does not degrade and provides sufficient solvent diffusivity for pulp based on the swelling effect. This significantly reduces heterogeneous microstructure aggregation and effectively promotes subsequent dissolution processes. The dissolved cellulose has more uniformity at the molecular level, showing lower dope relaxation time and gel temperature, which offers better alternatives for stable, high-viscosity lyocell spinning, and constructs stronger fiber compared to that of un-treated pulp.
研究领域:
材料科学
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化学工程
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产品关联
DOI
高影响因子
JOURNAL OF APPLIED POLYMER SCIENCE
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2013
·Vol. 129
·期 6
·3473-3481
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IF 1.395
Wan-Zhong Lang,Hai-Yan Niu,Ya-Xin Liu,Chun-Xia Liu,Ya-Jun Guo
The waste perfluoro-ion-exchange membranes (PFIEMs) in chlor-alkali industry were regenerated and used to the separation of dimethyl carbonate (DMC)/methanol (MeOH) mixtures by pervaporation process. The energy-dispersive spectrum (EDS) demonstrates that the impurities on the surfaces of waste PFIEMs can be effectively cleared by the regeneration process. The degree of swelling, sorption, and pervaporation properties of the regenerated PFIEMs with different counter ions were investigated. The results indicate that the counter ions of PFIEMs conspicuously influence the degree of swelling, sorption, and pervaporation properties for DMC/MeOH mixtures. The degree of swelling and solubility selectivity both decreases with the alkali metal counter ions in the sequence: Li + > Na + > K + > Cs + . The degree of swelling increases with MeOH concentration increasing in feed liquid. The pervaporation measurements illustrate that the permeation flux decreases and the separation factor increases with the rising in ion radius of counter ions. The increase of feed concentration (MeOH) and feed temperature is advantageous to improve permeation flux while at the cost of separation factor decreasing. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
研究领域:
高分子材料
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化学工程
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膜科学与技术
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环境化工
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分离科学
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DOI
高影响因子
Journal of Environmental Chemical Engineering
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2022
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IF 7.968
Zhong Sun,Yihan Yin,Yupeng An,Chao Deng,Ziyu Wei,Zijiang Jiang,Xixin Duan,Xiaohui Xu,Jing Chen
A cost-efficient and simple method, grafting sodium sulfonate groups (−SO 3 Na) onto carboxymethyl cellulose (CMC), was developed to form hydrogel adsorbents for the removal of poisonous metals including Cu(Ⅱ) and Zn(Ⅱ) from wastewater. In this work, cellulose-based hydrogels (CMC-g-P(AA-co-SS)) were prepared using acrylic acid (AA) and sodium styrene sulfonate (SS). FTIR, XPS , SEM , and EDX were employed to analyze the surface morphology and structure of CMC-g-P(AA-co-SS). The results revealed that the synergistic effect of −SO 3 Na and carboxylate groups (−COO − ) facilitated the adsorption of heavy metals. Moreover, introducing AA and SS enhanced the swelling degree of CMC hydrogels. The results of adsorption experiments showed that high adsorption efficiencies were obtained for Cu(Ⅱ) and Zn(Ⅱ) (200.44 mg/g and 192.28 mg/g, respectively) within 180 min. The adsorption isotherm and kinetics indicated that the monolayer chemical adsorption dominated the process. After 5 cycles, the adsorption activity of CMC-g-P(AA-co-SS) remained high, with the adsorption capacity for Cu(Ⅱ) and Zn(Ⅱ) being 93.3% and 78.3% of the original, respectively. Thus, the CMC-g-P(AA-co-SS) is a promising adsorbent candidate for the removal of poisonous metals from wastewater.
研究领域:
环境科学
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化学工程
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材料科学
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DOI
高影响因子
Journal of Materials Chemistry B
·
2019
·Vol. 7
·期 15
·2463-2473
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IF 5.047
Fenbo Ma,Yongmei Ge,Nian Liu,Xiangchao Pang,Xingyu Shen,Bin Tang
A composite hydrogel with tunable mechanical properties has been fabricated and characterized in this study. We investigated its swelling degree, morphology, structure and thermal stability. Moreover, the effect of strontium chloride concentration on both the dynamic rheology and nanomechanical properties of the composite hydrogels was confirmed in this work. To eliminate the viscoelastic influences of hydrogels during nanomechanical tests, we first analyzed the elastic modulus of strontium alginate (Alg-Sr) and strontium alginate/chondroitin sulfate (Alg/CS-Sr) hydrogels via atomic force microscopy (AFM) using the rate-jump method. Chondrocytes were cultured with the Alg-Sr and Alg/CS-Sr hydrogels respectively. Cell viability assay reveals that the Alg/CS-Sr hydrogel possesses good cytocompatibility. Flow cytometry, qPCR and western blotting analysis suggest that the Alg/CS-Sr hydrogel exerts a positive effect on the inhibition of apoptosis and may exert anti-inflammatory effects in articular cartilage related applications. Furthermore, the preliminary in vivo study shows that the Alg/CS-Sr composite hydrogel facilitates the repair of cartilage in rabbit cartilage defect. Taken together, it is indicated that the Alg/CS-Sr composite hydrogel might be a promising scaffold to promote the repair of cartilage defects.
研究领域:
生物材料
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组织工程
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生物医学工程
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产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）