ACS Applied Polymer Materials
·
2021
·
IF 4.089
Wenjie Sun,Jiaming Luo,Lei Zhang,Yue Chen,Pengxin Li,Yiting Zheng,Yonghong Cheng
Silicone-containing dynamically hindered urea bonds are developed as a smart insulating material for power equipment and electronic devices. In this work, silicones are constructed by isocyanate–piperazine-based dynamic bonds with cross-linking degree adjusted by glycerol. Healing and recycling based on dielectric and insulating properties are mainly emphasized in this study. We find that dynamic bonds not only heal the cut-damaged feature of the silicone but also enable dielectric property recovery. A healing efficiency above 95% and a recycling efficiency above 90% based on insulation performance are achieved. After recycling, cross-linked silicone exhibits only a slight variation in permittivity and tan δ, while linear silicone shows an apparent increase. Insulation performance of materials with different cross-linking agent concentrations is also investigated. A higher cross-linking degree was found to further improve insulation properties but reduces the recycling efficiency. Importantly, the developed silicones exhibit high intrinsic insulation properties, comparable to commercial silicone materials, which are very attractive for electrical applications.
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ACS Applied Polymer Materials
·
2026
·
IF 5.2
Zhifeng Nie,Hongxing He,Yi Zhang,Xiaodong Zhuang,Xiaoying Li,Ni Yang
Abstract Given the highly dispersed occurrence of rhenium in the natural environment, it is commonly encountered in conjunction with other minerals and primarily occurs as perrhenate ions (ReO4–) in the acidic waste solutions produced by nonferrous metallurgical operations. The advancement of techniques for the efficient, economical, and selective extraction of rhenium from metallurgical waste acids holds significant socio-economic value. In the present study, a functional polymer designated CY-PPZ, characterized by a conjugated amine structure, was synthesized via a one-pot reaction employing cyanuric chloride and piperazine as monomeric precursors, designed for the targeted adsorption of ReO4– ions. Experimental investigations revealed that CY-PPZ exhibited superior adsorption performance for ReO4– across a broad pH range (2–8), achieving adsorption equilibrium within 480 min and demonstrating a maximum adsorption capacity of 350.92 mg/g. The polymer also displayed remarkable selectivity and resistance to interference from competing ions, as evidenced by a distribution coefficient (Kd) of 14.34 L/g. Notably, in simulated metallurgical waste acid solutions characterized by elevated concentrations of competing anions, specifically with a molar ratio of ReO4– to NO3–, SO42–, and Cl– of 1:3000, the removal efficiency of ReO4– consistently exceeded 88.52%. Additionally, CY-PPZ exhibited excellent recyclability, retaining a removal efficiency of 90.20% after 8 successive adsorption–desorption cycles. Economic analysis indicated that each gram of CY-PPZ could yield an approximate socio-economic value of $26.866. Mechanistic insights obtained from XPS and DFT calculations confirmed that the primary adsorption mechanisms involved synergistic electrostatic interactions and chemical coordination between CY-PPZ and ReO4– ions. In summary, CY-PPZ emerges as a highly promising material for the selective, efficient, and cost-effective extraction of rhenium from metallurgical waste acid streams.
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Micromachines
·
2023
·Vol. 14
·期 11
·2112
·
IF 3.4
Gang Li,Wenjie Wu,Xuecheng Yu,Ruoyu Zhang,Rong Sun,Liqiang Cao,Pengli Zhu
Despite the considerable research attention paid to block copolymer (BCP)-toughened epoxy resins, the effects of their terminal groups on their phase structure are not thoroughly understood. This study fills this gap by closely examining the effects of amino and carboxyl groups on the fracture toughness of epoxy resins at different temperatures. Through the combination of scanning electron microscopy and digital image correlation (DIC), it was found that the amino-terminated BCP was capable of forming a stress-distributing network in pure epoxy resin, resulting in better toughening effects at room temperature. In a 60 wt.% silica-filled epoxy composite system, the addition of a carboxyl-terminated BCP showed little toughening effect due to the weaker filler/matrix interface caused by the random dispersion of the microphase of BCPs and distributed silica. The fracture toughness of the epoxy system at high temperatures was not affected by the terminal groups, regardless of the addition of silica. Their dynamic mechanical properties and thermal expansion coefficients are also reported in this article.Keywords:epoxy;block copolymer;induced microphase separation;fracture toughness;toughening mechanisms;digital image correlation
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高影响因子
CHEMICAL RESEARCH IN CHINESE UNIVERSITIES
·
2023
·Vol. 39
·期 5
·822-828
·
IF 3.1
Zhang Yu,Zheng Jianzhi,Li Xijuan,Wu Ying,Zhang Ke
A self-accelerating three-component reaction was developed using the secondary amines, CS 2 , and sym-dibenzo-1,5-cyclooctadiene-3,7-diyne (DIBOD) as reactants. In this three-component reaction, the secondary amine reacts with CS 2 to form dithiocarbamate anion, which subsequently in-situ reacts with DIBOD behaving a self-accelerating reaction property. Specifically, the reaction of dithiocarbamate anion with the first alkyne of DIBOD activates the unreacted alkyne, which reacts with dithiocarbamate anion much faster than the original alkyne of DIBOD. Using the self-accelerating three-component reaction as polymerization reaction, a stoichiometric imbalance-promoted step-growth polymerization method was developed using the difunctional secondary amines, CS 2 , and DIBOD as monomer groups. This novel three-component polymerization can quickly produce high molecular weight dithiocarbamate-containing polymers under mild conditions using a slight molar excess of DIBOD to difunctional secondary amine monomer. Containing sulfur elements in the backbones, the resultant polymers hold high refractivity and may find potential applications in optical and optoelectronic fields.
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JOURNAL OF MEMBRANE SCIENCE
·
2021
·
IF 8.742
Chengbao Geng,Pei Huang,Fangbo Zhao,Hongxing Dong,Hongyan Niu,Yue Zhou,Jun Shen,Jiaming Zhang
The weak interfacial force among the substrate with polyamide layer is always a non-ignorable issue for the traditional thin-film composite (TFC) membrane during actual operation. To solve this issue, herein, we have proposed an effective strategy, which is enhancing the long-term separation durability of the TFC membrane by fixing the polyamide layer on the substrate through covalent bonding. To start with, an amino-substituted polyethersulfone (PES-NH 2 ) was synthesized and blended with polyethersulfone (PES) to prepare a hydrophilic PES/PES-NH 2 substrate. Next, the amino group in the substrate could effectively react with a part of acyl chloride groups in the organic phase to form the stable covalent bond with the polyamide layer formed by interfacial polymerization. The prepared PES/PES-NH 2 TFC membrane possessed a denser polyamide layer with a higher cross-linking degree, as well as exhibited greatly increased separation performance at 0.6 MPa. Significantly, the PES/PES-NH 2 TFC membrane still maintained excellent separation performance under a long-term filtration period of 15 days, which is also much longer than the PES TFC membrane. This effective and promising method provides a valuable way to maintain the separation stability of TFC membrane in long-term operation.
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JOURNAL OF MEMBRANE SCIENCE
·
2019
·
IF 7.015
Xi Zhang,Chang Liu,Jing Yang,Cheng-Ye Zhu,Lin Zhang,Zhi-Kang Xu
Traditional nanofiltration membranes (NFMs) suffer from ultrafiltration substrates with low porosity, small pore size and relatively poor solvent stability. Herein, NFMs have been fabricated on a series of hydrophobic polymer microfiltration substrates to address these issues. Polyphenol-based coatings of tannic acid/diethylenetriamine (TA/DETA) were co-deposited on the hydrophobic substrates to improve their surface wettability and to make them appropriate for interfacial polymerization. The spreading behaviors of aqueous solutions, which are of significant importance to the formation of defect-free polyamide layers, were directly visualized by laser confocal microscopy . The influences of TA/DETA coatings on the interfacial polymerization were further demonstrated by both dynamic molecular simulation and nanofiltration performance evaluation. The as-prepared NFMs exhibit higher water permeation flux compared with traditional ones because of the large pore size and high porosity of the microfiltration substrates, as well as the relatively low cross-linking degree of polyamide layers. Internal stress during the nanofiltration process was calculated by the theory of thin plates and the results claim good pressure resistance for these NFMs. Therefore, the as-prepared NFMs can be steadily used under high operation pressures even up to 0.9 MPa, which are in accordance with the theoretical calculation. Furthermore, these NFMs also present good solvent resistance since the chemical stability of the no-polar hydrophobic substrates.
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Environmental Science-Water Research & Technology
·
2019
·Vol. 5
·期 8
·1412-1422
·
IF 4.195
Lulu Jia,Xuke Zhang,Junyong Zhu,Shenzhen Cong,Jing Wang,Jindun Liu,Yatao Zhang
Nanofiltration membranes with superior separation performance are highly desired for water treatment such as desalination. To fulfil the demand for higher permeability and selectivity for thin-film composite (TFC) membranes prepared via interfacial polymerization, nanoparticles were incorporated into the polyamide layer to construct thin-film nanocomposite (TFN) membranes. However, due to the inevitable aggregation of the nanoparticles and the weak adhesion between the nanoparticles and the polymer matrix, the separation performance of the TFN membranes are still not good enough to substitute the commercial NF membrane for desalination. Herein, a PVA-assisted halloysite nanotube (HNT) TFN membrane with high separation performance was fabricated. The HNTs were modified by poly(styrene sulfonate) to obtain m-HNTs with enhanced hydrophilicity and excellent dispersibility. To avoid the loss of nanoparticles during the interfacial polymerization process, a vacuum filtration process is combined with the membrane preparation procedure. The optimal TFN-0.05 membranes showed a superior water permeability of 34.5 L m−2 h−1 bar−1 and Na2SO4 rejection of 97.8% at 4 bar, which is almost twice that of the pristine TFC membrane and superior to the performance of the traditional desalination membranes. This facile strategy may provide a useful guideline for the construction of highly permeable TFN membranes for desalination.
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REACTIVE & FUNCTIONAL POLYMERS
·
2019
·
IF 3.074
Lei Zhang,Haiqing Wang,Zenghui Dai,Zhongxiang Zhao,Feiya Fu,Xiangdong Liu
Dynamic covalent chains that composed of three or five dynamic polyurea bonds are introduced into cross-linked polyurethane to overcome the classical dilemma between healing rate and thermo-mechanical properties. Comparing with dynamic urea bond, the incorporation of the dynamic polyurea chains with multiple leads to significantly improved thermo-mechanical performance and healing rate/efficiency on the network. Remarkably, several folds' increases in tensile and adhesion shear strength as well as 53 °C enhancement in glass transition temperature are achieved without sacrificing the material properties of the polyurethane network. We attribute the improvements to the decomposed polyurea chain segments, which have higher diffusivity and larger quantity than the dynamic urea bond that tied in the control network. This study provides a concept of dynamic covalent chain to address the classical dilemma between healing performances and thermo-mechanical properties among healable thermosets .
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ACS Applied Materials & Interfaces
·
2016
·
IF 7.145
Xi Zhang,Yan Lv,Hao-Cheng Yang,Yong Du,Zhi-Kang Xu
Thin-film composite (TFC) nanofiltration membranes are prepared via interfacial polymerization with a polyphenol coating as an interlayer for the thin and smooth polyamide selective layer. The polyphenol interlayer is simply fabricated by the codeposition of tannic acid and diethylenetriamine without changing the surface morphology of the polysulfone ultrafiltration substrate. An interfacial polymerization is conducted from piperazidine and trimesoyl chloride on the polyphenol interlayer to construct the polyamide selective layer. The as-prepared TFC nanofiltration membranes show nearly tripled fold of water permeation flux as compared with those prepared at the same condition without an interlayer. They also exhibit a high rejection to Na2SO4 (>98%) because the thin and defect-free polyamide selective layer is formed on the polyphenol interlayer. These nanofiltration properties have high reproducibility, which means the TFC nanofiltration membranes are suitable for scale-up industrial applications.
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高影响因子
Journal of Environmental Chemical Engineering
·
2025
·
IF 7.2
Yihan Yin,Qi Liu,Min Xiao,Hongxia Gao,Bo Jin,Zhiwu Liang
Membrane absorption has garnered significant attention due to its ability to combine the advantages of membrane separation and chemical absorption methods. During the scale-up of membrane absorption equipment, the fluid flow and mass transfer processes tend to have serious non-ideal effects, arising from the increase in aspect ratio and the number of membrane fibers. However, traditional one-dimensional (1D) and two-dimensional (2D) models are unable to describe the impact of geometry on mass transfer performance. In this study, a three-dimensional (3D) steady-state model is established to simulate the mass transfer process in a multi-fiber membrane contactor using COMSOL Multiphysics software. The 3D steady-state model is proven to be able to accurately predict the CO 2 absorption flux (J CO2 ) under various operating conditions by comparing the simulation results with experimental data. The results indicate a strong correlation between mass transfer performance and fluid velocity distribution. To further explore the flow behavior of gas and liquid at different locations, a 3D dynamic simulation model is developed and compared with experimental data. This model can describe the non-ideal flow behavior and the characteristics of gas and liquid phases in reactors with complex geometries. The results of the 3D dynamic model show that there are priority and slow regions for fluid flow, and CO 2 mass transfer performance can be enhanced by concentrating the membrane fiber arrangement in the priority region. The model developed in this study can be used to evaluate defects in fluid flow patterns, such as channeling, back mixing, and tailing. Furthermore, the 3D steady-state and dynamic models can guide the design of membrane contactors, optimize operating conditions, and provide a reference for analyzing fluid flow morphology and structural optimization in membrane contactors.
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RSC Advances
·
2024
·Vol. 14
·期 7
·4645-4652
·
IF 3.9
Shuai Zhou,Huifen Tan,Keke Chen,Xin Cheng,Xiaojuan Huang,Congjie Gao
Composite nanofiltration (NF) membranes prepared using interfacial polymerization (IP) have gained significant attention in the field of wastewater treatment. In this study, sodium camphor sulfonate (CSA-Na) and tetraethylammonium chloride (TEAC) were employed as aqueous phase additives to regulate the diffusion of piperazine (PIP) molecules through electrostatic interactions. The dissociated CSA-Na and TEAC in the aqueous solution formed an organic structure at a certain concentration, restricting the interfacial transport behavior of PIP monomers. The results show that when the content of CSA-Na is 2% w/v, TEAC is 3.9% w/v, that is, the material dosage ratio is 1 : 3, and the NF membrane shows the best performance, with a water flux of 55.61 L m−2 h−1 (test pressure is 0.5 MPa), and MgSO4 rejection rate of more than 98%.
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JOURNAL OF MEMBRANE SCIENCE
·
2025
·
IF 9
Yihan Yin,Hongxia Gao,Zhiwu Liang
Hollow fiber membrane contactors coupling amine absorption method have emerged as an ideal choice for carbon capture due to their high specific surface area, low cost, and ease of scalability. In this study, COMSOL Multiphysics 6.0 software was used to develop three-dimensional (3D) and two-dimensional (2D) models to investigate the CO 2 mass transfer performance of N-Methyldiethanolamine (MDEA) + Piperazine (PZ) and 3-Dimethylamino-1-propanol (3DMA1P) + 2-(Methylamino)ethanol (MAE) blended solutions under various operating conditions, and the simulation results were evaluated with the experimental data. The results indicate that the outcomes obtained from the 2D model are generally higher than the experimental data, whereas the results from the 3D model show good agreement with the experimental data. Considering the stringent convergence conditions, low computational efficiency, and the inability of 3D models to dynamically describe the changes in mass transfer performance under membrane wetting conditions, a 2D-3D hybrid model was developed, making it possible to efficiently compute mass transfer performance during the dynamic membrane wetting process. The hybrid model was developed by quantifying the uneven fluid distribution from the 3D model into correction factors for both the gas and liquid phases, and incorporating these factors into the original 2D model. By comparing the simulation results of the hybrid model with experimental data, it is found that the non-wetting hybrid model for the MDEA + PZ blended solution exhibits strong agreement with experiments, achieving an absolute average relative deviation (AARD) within 4.95 %. Meanwhile, for the 3DMA1P + MAE mixed solution, the 5 % wetted hybrid model accurately predicts mass transfer performance with an AARD of less than 5.55 %. Moreover, the results obtained from the hybrid model are consistent with those from the 3D model, while significantly reducing the calculation time from over 3 h to less than 1 h. This demonstrates that the hybrid model can efficiently and accurately predict CO 2 absorption flux (J CO2 ) and membrane wetting under various operating conditions.
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