Carbohydrate Polymer Technologies and Applications
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2020
·
IF 0
Wentao Huang,Liping Zhu,Dezhong Liu,Jiefu Li,Shuguang Yang
Alginate (ALG) and chitosan (CHI) are naturally occurring polymers, and present broad applications in various fields. Owing to the electrostatic interactions between the two polymers, ALG and CHI are combined to prepare fibers via diffusion controlled in-situ polyelectrolyte complexation. A map of the concentration combination of spinning and coagulation solution is presented for the fabrication of the complex fibers. When concentration combination meets the requirements for fiber formation, increasing the concentration of the spinning or coagulation solution will slow down the diffusion, which will affect the composition and mechanical properties of the prepared fibers. Prolonging complexation time or increasing temperature will enhance the diffusion, and more polyelectrolytes with opposite charged-groups will be taken from the coagulation solution, hence the fibers modulus will increase. In addition, the fiber composition and initial modulus are found to be correlated, and the inner structure of the fiber is revealed using the fluorescence imaging technique.
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
JOURNAL OF MATERIALS SCIENCE
·
2021
·Vol. 56
·期 11
·6704-6718
·
IF 4.22
Liu Xiao,Zhang Wenyi,Mao Linqiang,Yin Yong,Hu Linchao
Abstract FeOCl-MoS 2 was synthesized via calcination, which possessed excellent adsorption performance for methyl orange (MO). The characterization results showed that the FeOCl-MoS 2 was formed between MoS 2 and FeOCl phases, while a remarkable improvement in specific surface area and porosity was obtained in comparison with pure FeOCl and MoS 2 . The adsorption experiment results showed that the adsorption capacity of MO dye at 25 °C could reach 1615.11 mg/g. In addition, the pseudo-second-order kinetic model (R 2 > 0.99) has a good applicability to describe the adsorption of MO onto FeOCl-MoS 2 . Langmuir isotherm model (R 2 > 0.99) can describe the adsorption process well, proving that the adsorption is surface-controlled monolayer adsorption. Thermodynamic analyses showed the adsorption is an exothermic process and has spontaneity in nature. The adsorption of MO onto FeOCl-MoS 2 is attributed to electrostatic interaction. In particular, the adsorption capacity could still reach 82.1% of the initial adsorption capacity by alkali washing after five cycles. Hence, this study reveals that FeOCl-MoS 2 could be a high-efficient adsorbent for dyes removal from wastewaters. Graphical abstract
研究领域:
材料科学
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环境科学
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产品关联
DOI
高影响因子
Polymer Chemistry
·
2020
·Vol. 11
·期 29
·4741-4748
·
IF 5.342
Heng Chen,Beibei Hao,Penghui Ge,Shaojun Chen
Outstanding mechanical performances and designable architectures are essential for hydrogels when applied as structural materials. In this work, a series of physically cross-linked hydrogels were prepared by copolymerization of a hydrophobic monomer of butyl acrylate and an ampholytic cross-linker of 2-(dimethylamino)ethyl methacrylate and methacrylic acid, followed by soaking in water. The ampholytic cross-linker supported the 3D-printing fabrication of hydrogel precursors, and further hydrated to induce hydrophobic association and caused the transformation from hydrogel precursors to hydrogels. These hydrogels with a water content of 10.4–57.0 wt% possessed excellent mechanical properties, with a tensile strength, elongation at break, and Young's modulus of 61.0–103.4 kPa, 1150–1560%, and 42.7–125.7 kPa, respectively, and meanwhile exhibited fast and high autonomous self-healing ability. This work developed a facile strategy to prepare self-healing hydrophobic association hydrogels besides emulsion polymerization, and offer new ways to construct physically cross-linked hydrogels with designable architectures.
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
Carbohydrate Polymer Technologies and Applications
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2021
·
IF 0
Ali A. Altam,Liping Zhu,Wentao Huang,Hao Huang,Shuguang Yang
Spherical beads made of naturally derived polymers can be widely used as a promising matrix in many bio-related and safety required fields. Herein, the optimal parameters for fabrication of a core-shell bead composed of carboxymethylcellulose (CMC) and chitosan (CHI) are established based on systematic investigations on working distance, solution pH and polymer concentrations. Spherical beads will be obtained when the working distance is set as 15 cm. The beads prepared at pH 4.5 are the strongest and can resist to a force of up to 0.071 N. It will be shown that the critical concentration of polymer solutions plays important roles in determining the shape and size of beads. The observation of two new peaks at 1723 cm −1 and 1592 cm −1 in the FTIR of the prepared beads demonstrate the electrostatic interactions between CMC and CHI. With a post gentle heating (35°C), the stability of beads is significantly improved and the swelling degree in water increases to 220%.
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
Materials Chemistry Frontiers
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2019
·Vol. 3
·期 4
·606-614
·
IF 0
Ya Zhao,Weijing Fan,Hanying Zhao
Self-assembly of asymmetric structures has been attractive for applications in the fabrication of hierarchical structures. However, the role of the electrostatic interaction in the self-assembly of charged asymmetric particles in organic solvents has not been fully understood. In this research, self-assembly of positively charged patchy micelles in organic solutions and the reversible ultrasound responsivity of the assemblies are studied. Surface micelles (s-micelles) with cross-linked/quaternized poly(2-(dimethylamino)ethyl methacrylate) (q-PDMAEMA) cores and poly(oligo(ethylene glycol) monomethyl ether methacrylate) (POEGMA) coronae were prepared on the surfaces of silica particles. Positively charged patchy micelles were synthesized upon cleavage of the s-micelles. In THF, the patchy micelles self-assemble into vesicles with positively charged q-PDMAEMA in the walls and POEGMA in the coronae. The average size of the vesicles is dependent on POEGMA chain length. The repelling electrostatic interaction between the positively charged q-PDMAEMA patches in the walls is unfavorable for the achievement of low free energy of the assemblies, but it is energetically favorable for the vesicles to overcome energy barriers in the dissociation of the structures under ultrasound irradiation. The vesicle structures present reversible ultrasound responsivity. Under sonication the vesicles formed by patchy micelles dissociate into transient nanostructures, including aggregates and isolated patchy micelles. When the ultrasound is switched off, the transient nanostructures self-assemble into vesicles. By contrast, crosslinked vesicles do not show ultrasound responsivity. This research provides a new approach to the fabrication of responsive assemblies based on asymmetric structures, and the assemblies could find potential applications in medicine and bioengineering.
研究领域:
高分子化学
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纳米材料科学
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生物医学工程
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软物质物理
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药物递送系统
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DOI
CHEMICAL ENGINEERING JOURNAL
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2024
·
IF 13.3
Zhaorui Meng,Weihua Zhong,Dianbo Zhang,Qun Liu,Zhaoshuo Wang,Yandong Ma,Shichao Lu,Xu Hu,Tianying Sun
In extreme environments, it is difficult to balance the strength and toughness of ultra-thin film materials. To address this problem, we propose a promising strategy to build ultra strong, tough and extreme environments resistant Poly(p-phenylene-2,6-benzobisoxazole) (PBO) papers with a nacre-like structure constructed by synergistic electrostatic interaction and interlayer entanglement through the sol–gel-film method and hot press orientation. Highly interconnected PBO nanofibres （PNFs） with positive charges are tightly wound around the anisotropic graphene oxide (GO) nanosheets with negative charges through strong electrostatic interaction, forming a nacre like microstructure. The addition of Fe (Ⅲ) can form a coordination bond with the amino group on PNFs. Chemical crosslinking and hydrogen bonding synergize with interlayer entanglement effect among different PNFs，which can effectively dissipate interlayer energy and alleviate the conflict between strength and toughness. The resultant tensile strength and toughness are as high as 338.3 MPa and 16.04 MJ/m 3 ，which are 197.7 % and 425.4 % of those of the intrinsic PBO paper, respectively. Additionally, after 5000 folding-unfolding cycles, the tensile strength retention and toughness retention of the PBO/GO/Fe (PGFe) paper were still 85.4 % and 71.9 %, respectively. Moreover, the paper exhibits excellent tolerance to extreme temperature environments and showed extremely strong chemical stability.
研究领域:
材料科学
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纳米技术
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产品关联
DOI
高影响因子
CARBOHYDRATE POLYMERS
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2021
·
IF 9.381
Jingjing Pan,Yang Li,Kailun Chen,Yipeng Zhang,Hui Zhang
In this study, the alginate/chitosan composite aerogels based on electrostatic interactions and noncovalent crosslinking were fabricated using sol-gel method followed by freeze-drying process. The solution property results showed that with the addition of chitosan in alginate solution, a tighter network was induced by the more entangled molecular chains. The aerogel morphology observations showed that the pore diameter decreased with the increasing weight ratio of chitosan in the aerogels, but was even much lower after the crosslinking of excess alginate with calcium ions . After crosslinking, the aerogels presented the improved thermal stability and higher mechanical properties, as well as stronger antibacterial activities against Staphylococcus aureus and Escherichia coli . Therefore, the enhanced physical and antimicrobial properties of the alginate/chitosan aerogels may be achieved by modulation of electrostatic interactions and noncovalent crosslinking, suggesting the promising applications of these composite aerogels as active food packaging materials for antimicrobial purpose.
研究领域:
材料科学
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微生物学
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DOI
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
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2020
·
IF 5.774
Chao Yu,Jian Lu,Zhiqiang Hou,Zhongfei Ma,Xinyu Lin,Zeqing Dong,Wendong Xing,Yongsheng Yan,Yilin Wu
Exposure and distribution of recognition sites are critical for membrane separation materials to enhance adsorption and separation efficiency toward rubidium ion. Herein, we prepared the rubidium (Rb) ion separation membranes (Rb-ISMs) through a delayed phase inversion method taking advantage of the different polarities between ethanol and water. Fabrication process was conducted through immersion of a poly (vinylidene fluoride)/graphene oxide (PVDF/GO) casting solution into coagulating bath containing 18-crown-6 (18C6) grafted mesoporous silica, ethanol and water. After phase inversion process, the as-prepared adsorbent materials were immobilized on membrane surface by strong electrostatic interaction force. The method could effectively avoid the embedding and aggregation recognition sites, and the coagulating bath only required the ethanol and water that was relatively healthy and environmental. The Rb-ISMs prepared at optimal conditions showed enhanced rebinding capacity (49.344 mg g −1 ) towards Rb ± , with a superior rebinding selectivity (11.8, 6.82, 9.08 for Rb ± /Ca 2+ , Rb ± /Cs ± , Rb ± /Mg 2+ , respectively). Importantly, Rb-ISMs showed remarkable perm-selectivity and regeneration performance, which further demonstrated its potentials in the rapid and effective separation field of Rb ions.
研究领域:
材料科学
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环境科学
✓ 已验证
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
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2018
·
IF 6.735
Hailong Liu,Ruixue Sun,Shengyu Feng,Dengxu Wang,Hongzhi Liu
Developing a facile and rapid method to prepare adsorbents for an efficient and selective removal of dyes is of great importance for human health and environment. In this work, a silsesquioxane-based disulfide-linked polymer (DLP) was rapidly synthesized by a simple oxidative coupling reaction of octa(3-mercaptopropyl)silsesquioxane within 2 min at room temperature. The synthesized DLP demonstrated selective and efficient adsorption of cationic dyes over anionic dyes with the maximum capacities of 12.94 mg g −1 for methylene blue, 18.47 mg g −1 for rhodamine B and 26.69 mg g −1 for crystal violet. The high uptake and selectivity for cationic dyes was attributed to the electrostatic interactions between the anionic charges from sulfur and oxygen anions formed by the deprotonation of thiols and hydroxyls in the DLP and the cationic charges from the dyes, and the swelling behavior of the DLP. To investigate the adsorption process, the effect of various factors such as contact time, initial concentration, temperature, and pH on the adsorption activity of cationic dyes was studied. The adsorption equilibrium data showed a better fitting to the Langmuir isotherm model than the Freundlich model and the adsorption kinetics fitted well with the pseudo-second-order kinetic model, indicating that the adsorption process is mostly governed by the chemisorption behavior. Additionally, the absorbent was recyclable with the adsorption capacity being >95% after five times recycle adsorption. These results indicated that the present disulfide-linked polymer could be promisingly applied as an efficient adsorbent for the selective removal of cationic dyes from industrial wastewater.
研究领域:
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
Journal of Physical Chemistry C
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2011
·
IF 4.524
Jingfeng Dong,Mei Wang,Pan Zhang,Songqiu Yang,Jianyong Liu,Xueqiang Li,Licheng Sun
The readily obtained noble-metal-free molecular catalyst systems, with xanthene dyes (Rose Bengal, RB2–; Eosin Y, EY2–; and Eosin B, EB2–) as photosensitizers, [Co(bpy)3]Cl2 as catalyst, and triethylamine as sacrificial electron donor, are highly active for visible-light-driven (λ > 450 nm) hydrogen production from water. The turnover frequency is up to 54 TON/min versus RB2– with a RB2–/[Co(bpy)3]Cl2 molar ratio of 1:10 in CH3CN/H2O under optimal conditions in the first half hour of irradiation (λ > 450 nm), and the turnover number is up to 2076 versus RB2–. Comparative studies show the following: (1) The photocatalytic H2-evolving activity of the cationic cobalt complex [Co(bpy)3]Cl2 is apparently higher than the neutral cobaloxime complexes with xanthene dyes as potosensitizers, and also much higher than the analogous system of [Ru(bpy)3]Cl2/[Co(bpy)3]Cl2. (2) The UV–vis absorptions of xanthene dyes are red-shifted to different extents upon addition of [Co(bpy)3]Cl2 to the aqueous or CH3CN/H2O solutions of these dyes, while no change was observed in the UV–vis absorptions of photosensitizer with addition of the cobaloximes to the aqueous solution of RB2– or addition of [Co(bpy)3]Cl2 to the aqueous solution of [Ru(bpy)3]Cl2. (3) The fluorescence of RB2– is significantly quenched by [Co(bpy)3]Cl2, but not by the cobaloximes. These special performances of [Co(bpy)3]Cl2 are attributed to the electrostatically attractive interaction between the anionic organic dyes and the cationic cobalt catalyst. The probable mechanism for photoinduced hydrogen production catalyzed by the system of RB2–, [Co(bpy)3]Cl2, and triethylamine is discussed in detail on the basis of fluorescence and transient absorption spectroscopic studies.
研究领域:
化学
·
能源科学
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产品关联
DOI
高影响因子
Analytical Methods
·
2016
·Vol. 8
·期 45
·8042-8048
·
IF 1.915
Zhen Cheng,Fang Zhang,Xianping Chen,Lingling Du,Chutong Gao,Kejun Tan
A simple, highly sensitive and selective assay method has been developed for the determination of perfluorooctane sulfonate (PFOS), a kind of emerging persistent organic pollutant, which is bio-accumulative, resistant to degradation and toxic. It was found that PFOS can form complexes with protonated Janus Green B (JGB) through electrostatic interaction in pH 5.8 citric acid–sodium citrate (CA–NaCA) buffer medium resulting in a remarkable enhancement of the resonance light scattering (RLS) intensity of the system. The study shows that the maximum scattering wavelength is located at 319.0 nm and the enhanced RLS intensities are in proportion to the concentration of PFOS in the range of 0.05–9.0 μmol L−1 (R2 = 0.9958), with a detection limit of 5.6 nmol L−1 (3σ). Under the same experimental conditions, various perfluorinated compounds (PFPrA, PFBA, PFPeA, PFHeA, PFHpA, PFOA, PFNA, and PFBS) and JGB interactions were studied and the scattering signal changes very little. Based on the above discussion, a simple, highly sensitive and selective resonance light scattering analysis method was established for the detection of PFOS. In this work, the optimum reaction conditions were investigated. The reaction mechanism between JGB and PFOS was also studied by the absorption spectrum, scanning electron microscopy (SEM), the combination ratio and so on. This method is successfully applied to the selective detection of PFOS in environmental water samples with RSD ≤2.7%.
研究领域:
分析化学
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环境科学
✓ 已验证
DOI
高影响因子
JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY
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2019
·
IF 3.571
Chi Yan,David Julian McClements,Yuqing Zhu,Liqiang Zou,Wei Zhou,Wei Liu
This paper attempted to construct a high internal phase emulsion (HIPE) through altering interfacial behaviors using the electrostatic interaction between positive chitosan and negative octenyl succinic anhydride (OSA) starch. The partial polysaccharide complex of OSA starch/chitosan was used to stabilize HIPE, which was able to adsorb at the oil droplet interface and prevent the coalescence of oil droplets. The wettability of OSA starch was enhanced with the addition of positively charged chitosan, leading to the formation of partial complexes. The impact of pH and concentration of chitosan on the droplet size, surface charge, and interface behavior were investigated, and the formation of the polysaccharide complex was further confirmed by atomic force microscopy. The presence of the OSA starch/chitosan complex facilitated the formation of stable HIPE with a gel-like structure and satisfactory centrifugal and oxidative stability. These results are useful to provide information for fabricating polysaccharide-based HIPE delivery systems, which may help expand their application in the food industry.
研究领域:
食品科学
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生物材料
✓ 已验证
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）