JOURNAL OF APPLIED POLYMER SCIENCE
·
2022
·Vol. 139
·期 22
·52254
·
IF 3.057
Zhangcheng Gao,Lianfang Feng,Xueping Gu,Jintang Duan,Cailiang Zhang
Copolyureas have a variety of sequence structures because of the diversity of monomer types and quantities, which directly determine their properties. 4,4′-diphenylmethane diisocyanate (MDI), m-phenylenediamine (MPD), and polyoxypropylenediamine (D2000) are used as monomers to study the influence of mixing on the sequence structure of as-prepared copolyurea. D2000 as a macromolecular aliphatic diamine has an extremely high reactivity with MDI, which is two to three orders of magnitude higher than that of MPD with MDI. While the molecular chain of D2000 is much longer than that of MPD, resulting in that the reaction between D2000 and MDI is much easier to change from reaction control to diffusion control than that between MPD and MDI. It is verified that the enhanced mixing can dramatically reduce the hindered effect of diffusion, and promote the reaction of MDI and D2000 to change the sequence structure of as-synthesized copolyurea. Specifically, as the stirring speed increased from 100 to 800 rpm, the content of MPD-MDI-MPD segment decreased from 57 to 15 mol%, while that of MPD-MDI-D2000 and D2000-MDI-D2000 segments increased from 39 and 4 mol% to 64 and 21 mol%, respectively. As a result, the as-synthesized copolyureas become more ductile from the high tensile strength and hardness. More specifically, the Shore A hardness, tensile strength, and the broken elongation of the as-synthesized copolyureas were changed from 81, 56 MPa and 65% to 68, 40 MPa and 188%, respectively.
研究领域:
材料科学
·
化学工程
✓ 已验证
DOI
高影响因子
Scientific Reports
·
2017
·Vol. 7
·期 1
·1-9
·
IF 4.259
Ge Xue-hui,Geng Yu-hao,Zhang Qiao-chu,Shao Meng,Chen Jian,Luo Guang-sheng,Xu Jian-hong
Here in this article, we classify and conclude the four morphologies of three-phase emulsions. Remarkably, we achieve the reversible transformations between every shape. Through theoretical analysis, we choose four liquid systems to form these four morphologies. Then monodispersed droplets with these four morphologies are formed through a microfluidic device and captured in a petri-dish. By replacing their ambient solution of the captured emulsions, in - situ morphology transformations between each shape are achieved. The process is well recorded through photographs and videos and they are systematical and reversible. Finally, we use the droplets structure to form an on-off switch to start and shut off the evaporation of one volatile phase to achieve the process monitoring. This could be used to initiate and quench a reaction, which offers a novel idea to achieve the switchable and reversible reaction control in multiple-phase reactions.
研究领域:
化学工程
·
材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ACS Nano
·
2017
·
IF 13.942
Can Xu,Wei Bing,Faming Wang,Jinsong Ren,Xiaogang Qu
A versatile method for photoregulation of chemical reactions was developed through a combination of near-infrared (NIR) and ultraviolet (UV) light sensitive materials. This regulatory effect was achieved through photoresponsive modulation of reaction temperature and pH values, two prominent factors influencing reaction kinetics. Photothermal nanomaterial graphene oxide (GO) and photobase reagent malachite green carbinol base (MGCB) were selected for temperature and pH regulation, respectively. Using nanocatalyst- and enzyme-mediated chemical reactions as model systems, we demonstrated the feasibility and high efficiency of this method. In addition, a photoresponsive, multifunctional “Band-aid”-like hydrogel platform was presented for programmable wound healing. Overall, this simple, efficient, and reversible system was found to be effective for controlling a wide variety of chemical reactions. Our work may provide a method for remote and sustainable control over chemical reactions for industrial and biomedical applications.
研究领域:
化学
·
生物医学工程
·
材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ACS Applied Nano Materials
·
2022
·
IF 6.14
Yuting Liao,Dong Liu,Bin Wang,Zijian Wu,Miao Ni,Mengchen Wang,Cheng-Hua Wang,Yuan Lu
The intensification of microreactions is important for biological and chemical reactions with microliter volumes as reaction units, including microliter bioassay or protein synthesis. At the micro/nanoscale, the fluid flow is usually located in the laminar region, making the interaction between different layers of material more difficult. In the absence of external intervention, the microscale transport of substances is dominated by passive diffusion, leading to a lower mixing efficiency and longer reaction times, which is disadvantageous for reactions requiring timeliness, such as microliter bioassays. Therefore, the intensification of microreactions is essential. Here, a dual magnetic–photothermal microreaction control platform was created, based on the cooperative roles of a close-loop photothermally controlled magnetically active nanoswarm (PMANS) as a nanostir for quick fluid mixing and as a nanoheating agent for the reaction solution. The platform was demonstrated to be enhanced for microreactions by using the glucose oxidase and horseradish peroxidase cascade and cell-free synthetic superfolder green fluorescent protein reactions, which are typical in the fields of diagnostic testing and biomanufacturing, respectively. The rotational motion of the PMANS is controlled by the magnetic field to achieve efficient and homogeneous mixing of fluids at the microscale. On the other hand, the PMANS is used to heat the reaction system through light control. The construction of a dual magnetic–temperature control platform provided a new strategy for microreaction enhancement that was convenient, controllable, and broadly applicable. This control platform has great potential for microscale reaction enhancement in detection, sensing, catalysis, and synthesis.
研究领域:
生物化学
·
纳米医学
·
生物工程
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF HAZARDOUS MATERIALS
·
2024
·
IF 12.2
Xiaolu Yin,Jun Li,Xiaoxia Liu,Kaiqiang Huang,Yanzhao Yang
The recovery of palladium from spent auto-exhaust catalysts (SAE-catalysts) is of great significance for resource sustainability. Herein, we proposed an efficient closed-loop leaching and recovery method for palladium from SAE-catalysts using iodotrihalide ionic liquids (ILs). Recovery design was explored aimed at green leaching and process simplification. Iodotrihalide ILs exhibited exceptional performance in terms of leaching efficiency (99.1%), selectivity (selectivity > 6.8 ×10 3 ) and reusability (over 6 cycles). The mechanism study revealed that excellent leaching performance was attributed to the redox and complexation. Additionally, the chemical reaction-controlled model was best suited to describe the leaching process. Notably, under the optimal conditions determined by the response surface methodology, a high-purity Pd(II) solution (purity > 99.8%) was obtained. More significantly, it was ideal for practical applications due to the low-viscosity (36.0 cP), mild (55 °C) and one-step leaching and recovery. In conclusion, this work provides an eco-friendly method for recovering palladium from SAE-catalysts with its non-high corrosiveness and low environmental impact.
研究领域:
环境科学
·
材料科学
·
化学工程
✓ 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）