FIBERS AND POLYMERS
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2014
·Vol. 15
·期 8
·1609-1615
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IF 1.113
Yu Yuanyuan,Yuan Jiugang,Wang Qiang,Fan Xuerong,Wang Ping,Cui Li
Our previous studies have demonstrated that cotton fabrics treated with soluble immobilized-cellulase showed considerably lower degradation and higher retention of tensile strength than those treated with free cellulase. It is important to investigate the surface morphology and structure of cotton fibres for understanding the enzymatic degradation. In this study, the effects of the soluble immobilized-cellulase on the surface morphology and structure of cotton fibres were investigated. The ultrastructural changes in the fibre surfaces were inspected using Tapping-Mode Atomic Force Microscopy (TM-AFM) and scanning electron microscopy (SEM), and the results showed that the smooth surfaces could be obtained after the immobilized-cellulase treatment, and no obvious damage was observed on the fibre surfaces. The hydrogen bonds in the certain depth area beneath the fibre surface were investigated using Attenuated Total Reflectance Fourier-Transform Infrared Spectroscopy (ATR-FTIR) after the cellulase treatments. Furthermore, the result of fibre accessibility indicated that the hydrolysis occurring in the interior of the cotton fibres was limited during the immobilized-cellulase treatment. Crystalline index (CI) of the cotton fibres treated with free cellulase was slightly higher than that of fibres treated with immobilized cellulase.
研究领域:
材料科学
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生物化学
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产品关联
DOI
高影响因子
ACS Omega
·
2019
·
IF 2.584
Feng Shen,Shuang Sun,Jirui Yang,Mo Qiu,Xinhua Qi
A key problem in the conversion of cellulose into chemicals and fuels is the low product yield from cellulose due to its robust structure. In this work, for the first time, cellulose was pretreated with coupling of liquid nitrogen and ball milling (LN–BM) for cellulose hydrolysis. After the LN–BM treatment, the glucose yield from cellulose by HCl in water increased by almost 2 times and yield of formic acid catalyzed by H2SO4–NaVO3 was more than 3-fold that obtained from untreated cellulose. The yields were also much higher than that from the individually ball-milled cellulose. The structure variation of cellulose indicated that reduction of both crystallinity index and molecular weight contributed to improving the conversion efficiency, but the former was the dominant factor. The combination of liquid nitrogen and ball milling developed in this work is an effective and environment-friendly approach for cellulose pretreatment.
研究领域:
化学工程
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生物化学工程
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环境科学
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产品关联
DOI
PubMed
高影响因子
FIBERS AND POLYMERS
·
2016
·Vol. 17
·期 9
·1330-1335
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IF 1.022
Zhang Dezhi,Liu Mengru,Liu Yingying,Li Hailong
There is a challenge to find an effective and eco-friendly method to achieve the modification of fibers. The effect of laccase-TEMPO system on the properties of the bleached eucalyptus kraft pulp was investigated in this work. The results were demonstrated by the decreases in curl values and kink index. In addition, carboxyl and aldehyde groups were introduced in this reaction system. Compared with initial pulp, the contents of aldehyde and carboxyl groups of the treated pulp were increased from 42.6 μmol/g, 8.4 μmol/g to 125.4 μmol/g, 26.3 μmol/g respectively. However, the treatment had a detrimental effect on the thermal stability of pulp fibers. Moreover, the crystallinity index was slightly increased (from 82.1 % to 83.8 %) after the TEMPO-mediated oxidation, but the native crystalline structure was nearly unchanged. Furthermore, after the oxidation treatment, the relatively smooth film surface became textured, the carbon and oxygen bonds were changed, which were investigated by scanning electron microscope and X-ray photoelectron spectroscopy.
研究领域:
生物化学
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材料科学
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产品关联
DOI
高影响因子
NEW JOURNAL OF CHEMISTRY
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2017
·Vol. 41
·期 13
·5723-5731
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IF 3.269
Yue Sa,Yaru Guo,Xiaowei Feng,Man Wang,Ping Li,Yixue Gao,Xu Yang,Tao Jiang
Crystallinity is related to the degree of order and the crystal size of a given crystalline substance. It can affect the quality of hydroxyapatite (HA) and its abnormality can lead to diseases of hard mineralized tissues. Crystallinity index (CI) is a quantitative indicator of crystallinity. Various techniques, such as X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and Raman spectroscopy, and many methods based on these techniques have been used to define the CI of HA. The present study compares these methods and summarizes their characters for hydrothermally synthesized HA crystals with different aging time. Additionally, correlation coefficients between CIs calculated by different methods and crystal size (R12) and correlation coefficients among various CIs (R22) were obtained from linear-regression analysis. Scanning electron microscopy (SEM) was utilized as a supplementary technique to observe the morphological changes during the HA aging process. The results showed larger crystal size, increased crystallinity and more regular morphology of HA with increased aging time. All the R12 and R22 were above 0.9 and there were no significant differences between R12. However, different CI-calculating methods showed individual characters or limitations during their application. Such results suggested XRD, FTIR and Raman techniques used in this study were generally consistent and efficient but their special characters should be considered during their application. Researchers should choose certain appropriate technique and method to obtain CI on the basis of sample characteristics and experimental conditions.
研究领域:
材料科学
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生物医学工程
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产品关联
DOI
高影响因子
BIORESOURCE TECHNOLOGY
·
2021
·
IF 9.642
Yuanjie Gu,Lin Dai,Xin Zhou,Yong Xu
The chemical compositions of lignin, hemicellulose and cellulose are so far unascertained to various lignocellulose in respect to effect of cellulose enzymatic hydrolysis . The novel and environment-friendly gluconic acid (GA) pretreatment technology showed impressive results on the enzymatic hydrolysis of cellulose in various agricultural straws. However, only few of the main reasons or critical issues pertaining to this reaction are known. Therefore, the novel GA pretreatment was carried out to remove hemicellulose from the three representative waste straws under different conditions. Next, for the enzymatic hydrolysis of the residual cellulose fraction in the pretreated straws, some mathematical correlations have been investigated between enzyme accessibility, hemicellulose removal rate, and cellulose crystallinity index. Both linear and nonlinear models were compared using five-parameter logic curve, four-parameter logic curve, and Deming regression. Hemicellulose removal was logically ascribed to be the trigger for cellulose saccharification efficiency during GA pretreatment of these waste straws.
研究领域:
生物化学
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环境科学
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DOI
高影响因子
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
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2020
·
IF 3.99
Yue Jiang,Gaobo Yu,Yang Zhou,Yuanyuan Liu,Yuhong Feng,Jiacheng Li
In this work, we reported the in situ biological modification of bacterial cellulose (BC) using various sodium alginate with different molecular weights as the carbon source in the fermentation media. The presence of sodium alginate (SA) showed a great influence on the microstructure of the resulting components of bacterial cellulose incorporated with sodium alginate (SA-BCs), based on the characterization results of SEM images, FT-IR analysis, crystallinity index, and contact angles. With the addition of high molecular weight of SA, the resulting high molecular weight of SA and BC composite (H-SA-BC) demonstrated a narrower fiber and less intramolecular hydrogen bonds, as compared to the modified BCs with lower molecular weights. Specifically, the crystallinity index value of SA-BCs was observed to decrease with the increase of SA’s molecular weight. Using these SA-BCs as emulsifiers, the corresponding physicochemical properties and emulsifying performances of BC and SA-BCs in the stabilization of olive oil Pickering emulsion were fully assessed by Optical micrographs, the diameter of droplets and CLSM images. SA-BCs were proven to show stronger amphipathicity as compared to BC due to the lower molecular regularity of SA-BC and the presence of carboxyl groups. The droplets of the emulsions are observed to be smaller and more uniform when stabilized by the emulsifier of H-SA-BC. Therefore, the addition of SA in the biological modification of BC resulted in a great change in both morphology and amphiphilicity. These results would be helpful in the understanding of the development of natural materials as stabilizers for the potential applications of Pickering emulsions.
研究领域:
材料科学
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化学工程
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生物技术
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食品科学
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产品关联
DOI
高影响因子
BIORESOURCE TECHNOLOGY
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2021
·
IF 9.642
Qihong Zhang,Zhaohui Lu,Chen Su,Zongmiao Feng,Hui Wang,Jingbo Yu,Weike Su
Traditional methods of enzymatic hydrolysis of cellulose to cellulose nanocrystals (CNCs) are limited due to the low enzymatic efficiency and large amount of waste liquid. The purpose of this study is to improve the yield and production efficiency of CNCs by enzymatic hydrolysis. A one-step mechano-enzymatic hydrolysis method was developed by utilizing the synergy of wet grinding and enzymatic hydrolysis reaction to efficiently prepare CNCs. Under the optimal reaction conditions, the maximum CNCs yield of 49.3% was achieved with higher thermal stability and crystallinity index of 76.7%. Mechano-enzymatic hydrolysis followed the first order pseudo-kinetics, and fractal kinetics demonstrated that mechanical force of rotation speed affected the fractal dimensions and binding ability between substrate and enzyme. This study provides an alternative method to prepare CNCs, which can significantly avoid the use of bulk water, improve the production efficiency of CNCs and thus lower the production cost.
研究领域:
材料科学
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化学工程
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生物技术
✓ 已验证
DOI
PubMed
高影响因子
FOOD HYDROCOLLOIDS
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2023
·
IF 10.7
Yong Xie,Qingqing Liu,Haibo Liu,Zhiping Fan,Jia Shi,Xiong Liu
The favorable prebiotic effect of cereal β-glucans is associated with its structure characteristic, which may be influenced by thermal processing. This study aimed to evaluate the structure and in vitro fermentation characteristics of β-glucan isolated from hulless barley preprocessed with flaking-roasting (FR), stir-frying (SF), steam-flash explosion (SFE) and popping expansion (PE). The results showed that all thermal processing had no impact on the type of chemical groups. Compared with the native β-glucan, the molecular weight of PE-β-glucan increased from 147.36 × 10 3 Da to 5, 243.60 × 10 3 Da, whereas its crystallinity index decreasing from 52.9 ± 0.7% to 41.5 ± 1.1%. Furthermore, the PE-β-glucan exhibited a porous structure like that in native β-glucan, while the SFE-β-glucan displayed a compacted structure with the lowest molecular weight (89.90 × 10 3 Da). Expectedly, PE-β-glucan exerted the highest availability and increased the relative abundance of Bifidobacterium , while FR-, SF-, and SFE-β-glucan tended to promote the growth of Megasphaera and Lactobacillus . Additionally, the level of total SCFAs, acetate, propionate , and butyrate in PE-β-glucan were dramatically higher than those in other β-glucan. Overall, the chain conformation of β-glucan played a pivotal role in determining its bioavailability and probiotic characteristic, which could be improved evidently by PE processing.
研究领域:
食品科学
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营养学
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微生物学
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产品关联
DOI
高影响因子
CELLULOSE
·
2017
·Vol. 24
·期 11
·5025-5040
·
IF 3.417
Lin Fengcai,You Yuzhe,Yang Xuan,Jiang Xin,Lu Qilin,Wang Ting,Huang Biao,Lu Beili
A facile, green and efficient microwave-assisted method was developed to oxidize cellulose hydrogel beads with neutral 2,2,6,6-tetramethylpiperidinyl-1-oxyl radical (TEMPO)-mediated system. Resulting cellulose beads were investigated by scanning electron microscopy, solid-state 13 C-NMR spectra, and X-ray diffraction. The patterns of 13 C-NMR spectra indicated that the oxidation occurred only at C6 primary hydroxyl carbon, and the carboxyl groups amounted to 1.28 mmol/g in the cellulose beads. The TEMPO-oxidized cellulose beads showed highly porous structures consisting of nano-sized fibrils with retention of original spherical shapes, and the crystallinity index of the cellulose II almost unchanged after oxidation. The maximum adsorption capacity of rhodamine B, auramine O, malachite green and methylene blue on the TEMPO-oxidized cellulose beads was found to be 609, 537, 740 and 873 mg/g, respectively, and the adsorption process was well described by pseudo-second-order kinetics. In addition, desorption tests showed that TEMPO-oxidized cellulose beads could be regenerated by acid treatment and used repeatedly. Thus, TEMPO-oxidized cellulose beads prepared by microwave irradiation can be potentially used for the removal of organic dyes from industrial wastewater.
研究领域:
化学工程
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环境科学
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材料科学
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产品关联
DOI
高影响因子
ACS Sustainable Chemistry & Engineering
·
2025
·
IF 7.3
Qing Zhang,Enqing Zhu,Chi Zhang,Qingwen Tian,Lili Zhang,Jing Shen,Yonghao Ni,Zhiguo Wang
Deep eutectic solvents (DESs) present a promising pathway for sustainable lignocellulosic biomass fractionation, yet challenges such as solvent recyclability and maintaining product quality over repeated cycles persist, which is largely caused by hemicelluloses. A lactic acid/choline chloride (LA/ChCl) DES was employed to fractionate acid-hydrolyzed poplar chip biomass. After removing ∼96% of hemicellulose via acid hydrolysis pretreatment, the fractionation using fresh DES achieved a delignification degree of 90%, yielding cellulose-rich pulp over 90%. The DES was recycled up to five times, maintaining over 90% recovery in each cycle. However, the delignification degree decreased to 76% after five cycles. Supplementing fresh DES restored the delignification degree to 78%, while activated carbon adsorption further improved it to 88%. Importantly, structural analysis confirmed minimal degradation of DES, and the recycling process maintained the quality of the fractionated products. The lignin fraction exhibited high purity (>85%), stable molecular weight (∼7000 g/mol), low polydispersity index (∼1.70), and the cellulose fraction displayed efficient fiber separation while maintaining its natural crystalline structure (crystallinity index ∼80%). This work provides new process concepts for DES fractionation of biomass, offering a scalable and environmentally sustainable solution for lignocellulosic biomass processing within biorefinery frameworks.
研究领域:
化学工程
·
可持续化学
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生物质处理
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生物炼制
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绿色溶剂
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）