SCIENCE OF THE TOTAL ENVIRONMENT
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2021
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IF 7.963
Zhen-Zong Bao,Zhi-Feng Chen,Si-Qi Lu,Guangzhao Wang,Zenghua Qi,Zongwei Cai
Pollutant-attached microplastics have received increasing attention in recent years. However, information regarding the influence of hydroxyl group content of pollutants on the adsorption and desorption behavior is unclear, which affects their fate and risks in the aquatic environment. In this study, we investigated the adsorption and desorption behavior of anthracene (ANT) and its hydroxy derivatives (OHAs), including 2-hydroxyanthracene (MOHA), 2,6-dihydroxyanthracene (DOHA), and 1,8,9-trihydroxyanthracene (TOHA) on polyvinyl chloride (PVC) microplastics, and their interaction mechanism through the batch, characterization, and computational experiments. The results showed that the adsorption of ANT and OHAs on PVC microplastics conformed to the pseudo-second-order kinetic model and was exothermic spontaneously. The adsorption efficiency on PVC followed the order of ANT > MOHA > DOHA > TOHA, indicating that increase in hydroxyl group substitution degree will inhibit pollutant adsorption on PVC microplastics. Conversely, the release amounts of MOHA from PVC into simulated gastric fluids were higher than those of ANT. Experimental and computational results suggested that the affinity of ANT/OHAs to PVC microplastics was the most likely outcome in hydrophobic effect, electrostatic repulsion, and CH-π interaction forces. These findings help elucidate the mechanisms of pollutant adsorption on microplastics and evaluate the risk of pollutant-attached microplastics in the aquatic environment.
研究领域:
环境科学
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污染生态学
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DOI
PubMed
高影响因子
JOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE
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2022
·Vol. 102
·期 13
·5814-5825
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IF 4.125
Xin-lei Zhao,Yi-hong Bao,Yang Guo,Jia-yuan Luo,Shi-long Jiang,Xue Yang
BACKGROUND For decades, pine nut oil Pickering emulsions have been stabilized using a covalent composite of two phenolic chemicals (tannic acid, TA; and gallic acid, GA) and whey protein isolate (WPI) following alkali treatment. Based on covalent composite particles being excellent sources of high-quality stabilizers, this research explored the influence of phenolic addition and hydroxyl content on stability, rheological parameters and characterization of Pickering emulsions. RESULTS Tannic acid was more effective in reducing the average particle size of the emulsion, which decreased from 479.4 ± 2.1 nm without addition to between 187.6 ± 5.9 and 368.2 ± 16.8 nm ( P < 0.05). The potential values of all the emulsions were between −30 and −50 mV (except for the gallic acid addition of 2.5 g kg −1 ). When the phenolic addition was 7.5 g kg −1 , emulsions demonstrated the best emulsification ability. Pickering emulsion stabilized by WPI-TA and WPI-GA particles were successfully generated, according to confocal laser scanning microscopy. Rheological results showed that the increase of phenolic addition contributed to larger elastic modulus ( G ′), viscosity modulus ( G ″) and viscosity of emulsions, which was beneficial to the stability of emulsions. CONCLUSION Both phenolic compounds significantly improved the physicochemical stability of the emulsions ( P < 0.05) and their oxidative stability. Covalently crosslinking phenolic compounds to proteins is a better method to prepare stable emulsions. It is more prominent that TA shows a more significant improvement in emulsion stability due to the number of hydroxyl groups it can provide. This research might serve as a theoretical foundation for enhancing the quality of pine nut oil-related products. © 2022 Society of Chemical Industry.
研究领域:
食品科学
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化学工程
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产品关联
DOI
PubMed
高影响因子
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
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2022
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IF 5.518
Shasha Yan,Lanfang Chai,Wei Li,Ling-Ping Xiao,Xiaohong Chen,Run-Cang Sun
Although pH-sensitive lignin-based materials have extensively attracted attentions because of the smart response to pH, it is still a challenge to realize the regulation of the pH-responsive properties. Focusing on this problem, we proposed a new method by tunning the content of hydroxyl groups to adjust the performances of lignin-based hydrogel (L-HG). The modified lignins with the hydroxyl content ranged from 0.31 to 5.91 mmol/g were obtained after acetylation or demethylation . As the results, when increasing the hydroxyl content, the gels became more compact and smooth, and the tensile strength reached 4.10 MPa. The strain was up to 83.2%, and the bending behavior occurred more easily at various pH (3, 5, 9, 11 and 13). While decreasing the hydroxyl content resulted in the impairments of almost all of the above performances. Based on the test of the moisture content, the pH-sensitive bending behavior might be mainly caused by the opposing forces of hydrophilic and hydrophobic interaction. Finally, the application test showed that the trimmed hydrogel could hook up 10 times weight greater than itself under both acid and alkaline conditions. We believe that this work would provide the theoretical guidance for the regulation of pH sensitivity of L-HG.
研究领域:
材料科学
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生物化学
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DOI
高影响因子
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
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2019
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IF 3.131
YinChen Chen,Shiyu Fu,Hui Zhang
Acetic acid lignin (AAL) obtained from Bagasse was used as a partial substitute of polyols for polyurethane (PU) adhesive due to the presence of reactive sites, i.e. aliphatic and aromatic hydroxyl groups, in its structure. To improve its reactivity, lignin is partly demethylated before the copolymerization with polyisocyanate. The demethylation , catalyzed by hydrobromic acid solution under heating conditions, resulted in a decrease of methoxy groups on the phenyl ring and the increase of phenolic hydroxyl groups . It is found that 120 ℃ is the preferred temperature for the demethylation resulted in a 36.5 % increase in hydroxyl content of lignin up to 5.25 mmol/g. Lignin-based polyurethane adhesives were prepared in two steps including preparing a prepolymer based on mixtures of toluene-2,4-diisocyanate (TDI) and unmodified or demethylated lignin, and then the polymerization was completed by adding polyethylene glycol (PEG). The mass ratio (1:1) of TDI: (lignin + PEG) in the compositions was here investigated. The results indicated that the presence of lignin (with and without demethylation) in polyurethane adhesives increased the glass transition temperature , Young’s modulus, and elongation at break. Particularly, the tensile strength was increased by 15–36 MPa with the addition of 10–30 wt% of lignin. Lignin with higher amount of hydroxyl groups prepared by partly demethylation is better integrated into the three-dimensional cross-linking networks of the covalent polymer as a substitute of polyols. Compared to those PU adhesives based on the raw AAL, the adhesives prepared by demethylated lignin have higher tensile strength and thermal stability. It indicates that the demethylation is effective and it is a good strategy to prepare lignin-based PU adhesive with favorable mechanical properties .
研究领域:
材料科学
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化学工程
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DOI
高影响因子
JOURNAL OF WOOD CHEMISTRY AND TECHNOLOGY
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2014
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IF 1.176
Lihong Hu,Hui Pan,Yonghong Zhou,Chung-Yun Hse,Chengguo Liu,Baofang Zhang,Bin Xu
A new approach to increase the reactivity of lignin by thiol-mediated demethylation was investigated in this study. Demethylated lignin was characterized by the changes in its hydroxyl and methoxyl groups, molecular weight, and other properties using titration and spectroscopy methods including FT-IR, 1H NMR, UV, and GPC. The total, phenolic, and aliphatic hydroxyl contents in lignin increased while the methoxyl content decreased after demethylation reaction, which indicated the occurrence of demethylation reaction. The results from FT-IR and UV analysis also indicated that the kraft lignin in this study contains mainly guaiacyl moiety and demethylated lignin has a higher guaiacyl content than original lignin. The average molecular weight of lignin decreased after demethylation reaction due to the cleavage of ether linkages in lignin macromolecules. No severe degradation of lignin was observed during the demethylation reaction.
研究领域:
林产化学
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生物质化学
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DOI
高影响因子
Biofuels Bioproducts & Biorefining-Biofpr
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2021
·Vol. 15
·期 4
·1110-1125
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IF 4.102
Tian He,Wenxiang Zhu,Mingyou Liu,Xiaofei Tian,Fangeng Chen
Highly reactive polyols were prepared from modified acetic acid lignin (AAL) by a two-step combination of mild hydrothermal degradation and hydroxylation. The AAL-based polyols became relatively reactive and compatible with diisocyanate, with a reduction in the number average molecular weight (M n ) from 2923 to 684 g/mol and an increase in the hydroxyl content from 5.21 to 9.13 mmol/g. The mechanical performance and thermal properties of the AAL-based polyurethane elastomers (LPUEs) strongly depended on the molecular weight and hydroxyl content of the AAL-based polyols in the partial substitution of polytetramethylethylene ether glycol (PTMEG). This study proposed the prospective utilization of AAL as an alternative resource in the synthesis of polymers and biomaterials. © 2021 Society of Industrial Chemistry and John Wiley & Sons Ltd.
研究领域:
材料科学
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化学工程
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DOI
高影响因子
POLYMER
·
2018
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IF 3.483
Xuhui Zhang,Zhenghai Tang,Baochun Guo
As diene rubber products are generally fabricated with complicated curing package involving toxic additives, the exploration of alternative green curing chemistry for diene rubber is of great importance. In this contribution, we demonstrate a curing chemistry based on oxa-Michael reaction for diene rubber to achieve the combination of simple curing system and tunable mechanical properties . Specifically, pendent hydroxyls are introduced onto the solution-polymerized styrene-butadiene rubber (SSBR) via thiol-ene click reaction and the modified SSBR is effectively cured by various acrylates without the use of any additional additives. The mechanical behaviors of vulcanizates can be widely regulated by manipulating the network structures, which is tuned by curing temperature, hydroxyl content of SSBR, content and functionality of acrylates. The correlation between mechanical properties and network structure is accordingly achieved, which provides essential basis for the future application of the diene rubbers cured by oxa-Michael reaction.
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
INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
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2020
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IF 5.162
Yinchen Chen,Hui Zhang,Zhaodong Zhu,Shiyu Fu
Lignin is a good candidate for the polymerization and chemical modification to prepare sustainable chemicals and materials, but a relatively low hydroxyl content becomes an obstacle for the preparation of lignin-based polyurethane (PU) adhesives. In order to improve its reactivity, the acetic acid lignin (AAL) was hydroxymethylated before copolymerized with isocyanate during the preparation of PU adhesives. The hydroxymethylation was carried out in an alkaline formaldehyde solution and it was found that 85 °C is the optimal temperature. On that condition, the free formaldehyde content of the corresponding product HL-6 was as low as 0.32%, while the hydroxymethyl was increased by 189.11% compared with original AAL and reached 2.92 mmol/g. In the polymerization of PU adhesives, the hydroxymethylated lignin with a higher aliphatic hydroxyl content formed a more compact three-dimensional urethane cross-linking network with isocyanate. The mechanical properties and thermal stability of the lignin-based PU adhesive were improved by 15–30 wt% in HL-6, and particularly the tensile strength was increased by 21–41 MPa, which indicated that the hydroxymethylation is an efficient way to enrich the hydroxyl in lignin, and the modified lignin is adequate to partially replace petroleum-based polyols for the preparation of PU adhesives with excellent properties.
研究领域:
材料科学
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化学工程
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DOI
PubMed
高影响因子
HOLZFORSCHUNG
·
2023
·Vol. 77
·期 6
·437-452
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IF 2.4
Haonan Zhang,Qi Liu,Yanchen Zhu,Zhang Feng,Hao Ren,Huamin Zhai
In this study, representative lignin samples differing in hydroxyl content, molecular weight, linkage composition and lignin units ratio were prepared from eucalyptus wood by different isolation means and modification means: milled wood lignin (MWL), kraft lignin classified at different pH (KL), lignocresol (LC), lignoresorcinol (LR), lignopyrogallol (LP) as well as lignocresol secondary functional switched samples (LC 2 nd deriv). The structure of various lignins was characterized in detail by Fourier transform infrared (FT-IR) spectroscopy, gel permeation chromatography (GPC) and nuclear magnetic resonance (NMR). In order to eliminate the interference of other factors, bovine serum albumin (BSA) with relatively simple protein structure and different kinds of lignin and their derivatives were selected as the research objects. The adsorption/desorption behavior and mechanism between lignin samples and BSA were studied by quartz crystal microbalance with dissipation monitoring (QCM-D). The results showed that the content of phenolic hydroxyl was the main factor affecting the interaction of lignin and BSA, but in addition, the molecular size, linkages composition and the types of lignin units also had important effects on its adsorption behavior. The research will provide theoretical guidance and all-round reliable basic data for the interaction of lignin on lignocellulose hydrolysis enzymes in industrial application.
研究领域:
生物化学
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材料科学
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DOI
高影响因子
POLYMER
·
2018
·
IF 3.483
Shuangbin Fu,Yusheng Qin,Lijun Qiao,Xianhong Wang,Fosong Wang
In the past decade, poly(carbonate ether)polyols, or CO 2 -polyols, have been synthesized by the copolymerization of CO 2 and propylene oxide (PO) with a double metal cyanide (DMC) catalyst in the presence of various chain transfer agents. CO 2 -polyols show great potential use as substitutes for polyols derived from fossil feedstock in the polyurethane industry. Brookfield viscosity tests have revealed the importance of primary hydroxyl (1° OH) content in the reactivity of CO 2 -polyols; in particular, the low 1° OH content of CO 2 -polyols severely limits their application in foam materials . Incorporation of more carbonate linkages has proven to be only moderately efficient for preparing CO 2 -polyols with high 1° OH content, e.g., 19 F NMR spectroscopy indicates that the 1° OH content of a CO 2 -polyol can increase from 13% to 39% when the carbonate content in the CO 2 -polyol is increased from 26.1% to 80.0%. In this study, the PO end-capping route was developed using a strong Lewis acid, such as tris(pentafluorophenyl)borane (FAB) as a catalyst, and a CO 2 -polyol with 1° OH content of 60% was synthesized.
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
CHINESE JOURNAL OF POLYMER SCIENCE
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2025
·
IF 4
Yan Qin-Yu,Song Shun-Gang,Zhou Bu-Jie,Hu Jing,Feng Lian-Fang,Gu Xue-Ping,Zhang Cai-Liang
Poly(phenylene oxide) (PPO) exhibits excellent dielectric properties, making it an ideal substrate for high-frequency, high-speed copper-clad laminates. The phenolic hydroxyl group at the end of PPO plays a key role in its reactivity. Accurately quantifying the phenolic hydroxyl content in PPO is essential but challenging. In this study, we proposed a method for measuring the phenolic hydroxyl content of PPO using differential UV absorption spectroscopy. In alkaline solutions, the phenolic hydroxyl in PPO completely ionizes to form phenoxide ions, leading to a significant increase in UV absorbance at approximately 250 and 300 nm. Notably, the differential UV absorbance at approximately 300 nm was directly proportional to the phenolic hydroxyl concentration. Using 2,6-dimethylphenol as a standard, a calibration curve was established to relate the phenolic hydroxyl concentration to differential UV absorbance at approximately 300 nm, providing a precise and straightforward method for phenolic hydroxyl quantification in PPO with distinct advantages over conventional techniques.
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产品关联
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高影响因子
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
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2014
·
IF 2.235
Ren Liu,Junchao Zheng,Ruixi Guo,Jing Luo,Yan Yuan,Xiaoya Liu
A series of biobased UV-curable antibacterial resins were synthesized through modifying tannic acid (TA) with varied amount of glycidyl methacrylate (GMA). The obtained TA-based methacrylates exhibited good film-forming property and can be cross-linked under UV irradiation. Thus, antibacterial functionalities can be tethered in the coating matrix, eliminating the loss of antibacterial ingredients. The antibacterial properties of resins and corresponding coatings against Gram-positive Staphylococcus aureus and Gram-negative Escherichia coli were tested. The resins with high content of phenolic hydroxyl groups retained strong antibacterial ability while the ones with a relatively low content of phenolic hydroxyl groups did not, which indicated that the antimicrobial effects of TA greatly depended on the content of phenolic hydroxyl groups. The applications of UV-curable antibacterial resins in coatings were also studied. The cured coatings of TA-G5 resins with the highest content of phenolic hydroxyl groups exhibited the highest antibacterial activity with 5 log reduction. The basic properties of UV-cured coatings were also fully characterized, and the results demonstrated that the novel UV-curable resins had potential applications in UV-curable antibacterial coatings.
研究领域:
高分子化学
·
材料科学
·
抗菌材料
·
涂料技术
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生物基材料
·
光聚合
·
表面功能化
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DOI
高影响因子
危险品化学品经营许可证（带存储）