JOURNAL OF POLYMER SCIENCE PART B-POLYMER PHYSICS
·
2018
·Vol. 56
·期 11
·833-841
·
IF 2.499
Xinxiu Cao,Liang Chen,Kefeng Zhao,Jiangang Liu,Yanchun Han
Understanding the nucleation process is very important in growing polymer nanowires as it plays a decisive role in determining the crystal structure and size distribution. Polymer chain conformation determines whether the polymer chains could assemble to nuclei or not. Here, chain conformation and the nucleation process were controlled to grow 3,6-bis-(thiophen-2-yl)- N , N ′-bis(2-decyl-1-tetradecyl)-1,4-dioxo-pyrrolo[3,4-c]pyrrole and thieno[3,2-b]thiophene (DT-PDBT-TT) nanowires. We changed the conformation of DT-PDBT-TT in solution and controlled the nucleation process by using a main solvent:cosolvent system. The main solvent was a low boiling point good solvent, and the cosolvent was consisted of two high boiling point solvents with different solubility. In fact, the chain conformation in the pristine solution was changed by choosing different main solvents (with H-bond, π–π or none interaction with the main chain) and temperatures. The absorption spectrum and TEM images showed that trichloro ethylene (TCE) was the best main solvent because it has H-bond interaction with the polymer main chain and DT-PDBT-TT conformation in it approaching unimer coil conformation, which is beneficial to grow nanowires. Mixed o-dichlorobenzene (ODCB) and anisole (AS) with different ratios were used to changing the solubility step by step to control nucleation process. Only when marginal cosolvent (ODCB:AS = 1:1) was added, could it decrease the nuclei number and avoided the aggregates simultaneously. As the main solvent evaporated slowly, the nucleation and growth happened, leading to the nanowires formation. The resulting nanowires were about 63 nm in width and one to two microns in length. The width of the DT-PDBT-TT structures suggests that the polymer chains are oriented along the fibril axis. Our results indicated that there are two requirements for the nanowire formation, (1) the polymer chain conformation should approach unimer coil; (2) the nucleation density should be optimized, not too much and no aggregation happened. © 2018 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2018 , 56 , 833–841
研究领域:
高分子物理
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材料科学
·
纳米科技
·
凝聚态物理
·
有机电子学
✓ 已验证
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2023
·
IF 15.1
Murong Xi,Zhenjie Liu,Rui Sheng,Jiafeng Zhu,Yong Guo,Juan Ding,Xingchao Wang,Yue Zhang,Lei Wang,Zhipeng Sun,Wenjun Zhang,Jiulin Wang,Yudai Huang
Dissolutions of the polymer in the chaotropic salts follow Hofmeister effect, and the aggregate of salts and solvents shows new influence of the Hofmeister effect. Here, we reveal the aggregation of ion–solvent in chaotropic salt solution catalyzes the formation of the exposed Lewis acid-base center and realizes the dissolution of polyamide (PA) macromolecules. The relationship between Hofmeister effect, aggregate chemistry and Lewis acid-base chemistry is examined from new perspective. And then, a new solvent system and phase conversion process are designed for polyamides. Finally, the applications of PA in ZIBs as coating layer and binder are realized. As an electrode coating, it can effectively inhibit hydrogen evolution, corrosion and dendrite problems and improve the cycle life (cycle over 1500 h at 0.5 mA cm −2 ). As a binder, the active material adhesion on current collector, uniformity and wettability of the electrode are improved. The assembled pouch-cell with PANI cathode shows a capacity of 150 mAh g −1 after 120 cycles. This work reveals the secret of controlled phase transformation of polyamide in saline solution from a new perspective. And this phase conversion method is simpler, greener and more environmentally friendly, which greatly accelerates the application of polyamide in the field of membrane science and binder science.
研究领域:
高分子化学
·
电化学
·
材料科学
·
能源存储
·
膜科学
·
粘结剂科学
·
物理化学
✓ 已验证
DOI
高影响因子
JOURNAL OF CHEMICAL THERMODYNAMICS
·
2017
·
IF 2.726
Tianhua Huang,Dingqiang Lu,Xiuquan Ling,Xinxian Wang,Tongqi Liu,Fangfang Shen,Kefei He
In this paper, we focused on solubility and solution thermodynamics of istradefylline. Herein, we investigated the solubility and solution thermodynamics of istradefylline in binary solvent mixtures by gravimetric method. The solubility of istradefylline in (ethyl acetate + isopropanol), (ethyl acetate + tetrahydrofuran) and (ethyl acetate + acetone) was measured in the temperature range of 278.15 K–333.15 K under atmospheric pressure. In order to correlate the solubility of istradefylline, we employed the modified Apelblat equation, general cosolvency model and Jouyban-Acree model. Computational results showed that the modified Apelblat equation and general cosolvency model have low mean deviation. As calculated by van’t Hoff equation, the values of thermodynamic properties such as Gibbs energy, enthalpy, and entropy proved that the dissolution process is endothermic.
研究领域:
药物化学
·
药剂学
·
物理化学
·
药物热力学
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分子溶解行为
·
药物结晶
✓ 已验证
DOI
高影响因子
RSC Advances
·
2014
·Vol. 4
·期 52
·27259-27266
·
IF 3.708
Libin Yang,Feng Xin,Junzhong Lin,Zhuang Zhuang,Rui Sun
In this study, a hydrothermal synthesis was developed to prepare a thin titanium silicalite-1 catalyst layer in the internal channels of the honeycomb cordierite support, which was used in a continuous heterogeneous reaction. The as-prepared thin TS-1 catalyst layer was characterized by SEM, XRD, UV-vis and ATR-FTIR methods. Multiple hydrothermal syntheses were used for controlling the crystalline growth to optimize catalytic activity and lifetime. Moreover, a monolithic TS-1/cordierite reactor with external looping was utilized to investigate the characteristics of the continuous heterogeneous ammoximation reaction without the organic solvent tert-butanol (TBA). The reaction results showed that the conversion of cyclohexanone and selectivity of oxime approached more than 0.96 and 0.98, respectively. When compared with the reaction using TBA as the reaction solvent, the activity of the monolithic TS-1/cordierite showed no differences except for a longer lifetime.
研究领域:
化学工程
·
催化化学
·
材料科学
·
工业化学
·
绿色化学
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）