Ultrafast Science
·
2024
·
IF 0
Guang Huang,Junzi Li,Zilin Zhou,Zongtao Huang,Wei Kong,Fangteng Zhang,Youjun Zeng,Guanyu Liu,Tingchao He,Lin Ma
Singlet fission (SF) is a spin-conserving process converting 1 singlet exciton into 2 triplet excitons. This exciton multiplication mechanism offers an attractive route to solar cells that circumvent the single-junction Shockley–Queisser limit. However, it remains unclear how intermolecular coupling, which is subject to the aggregation extent in thin-film morphology, controls SF pathways and dynamics. The prototype molecule 6,13-bis(triisopropylsilylethynyl)-pentacene (TIPS-pentacene) has been extensively studied to investigate SF mechanisms. However, previous literature reports have presented divergent SF mechanisms and pathways in TIPS-pentacene films. In this study, solvent vapor annealing treatment is used to deliberately adjust the aggregation extent in TIPS-pentacene films. This enables us to reproduce various SF pathways reported in the literature under the same experimental conditions, with the only variation being the level of aggregation. These results shed light on the crucial role that molecular aggregation plays in modulating both the SF mechanism and pathway and reconciles the previously contentious SF mechanisms and pathways reported in TIPS-pentacene films. Our study offers substantial insights into the understanding of the SF mechanism and provides a potential avenue for future control of SF pathways in accordance with specific application requirements.
研究领域:
化学
·
材料科学
·
物理学
✓ 已验证
DOI
Journal of Materials Chemistry C
·
2025
·
IF 5.1
Tao Jin,Wenju Li,Yongyi Zhang,Ruiheng Wang,Shuai Wang,Chen Pan,Guan Wang,Jiacheng Zhang,Lei Yao,Jing Zhang,Qichun Zhang
Artificial synapses have gained considerable attention in modeling artificial visual systems. Facile and efficient p-n heterojunction, acting as the essential component, plays a critical role in configuration optimization and processing capabilities. Herein, we introduced a novel charge-transfer cocrystal that consisted of 5,8-dihydroindolo[2,3-c]carbazole (DDCB) and 7,7,8,8-tetracyanoquinodimethane (TCNQ) via solution-process, which demonstrated good crystallinity and typical n-type charge transport characteristics. To realize good charge storage ability, crystalline p-n heterojunctions with a phase-separated heterostructure were one-step prepared by drop-casting TIPS-pentacene and DDCB/TCNQ solutions onto the substrate. The as-prepared artificial synaptic devices exhibited remarkable paired-pulse facilitation (PPF), spike-duration dependent plasticity, spike-intensity dependent plasticity, and learning-experience behaviors similar to those of biological synapses in response to light pulses. Furthermore, based on the light potentiation and electrical depression modulation properties of these synaptic devices, we constructed artificial neural networks for image recognition, achieving a validation accuracy of over 97% on the modified national institute of standards and technology (MNIST) dataset. This work provides a new simple approach in establishing p-n heterojunction based artificial synapses for applications in light information processing, artificial vision, and memory simulation.
研究领域:
材料科学
·
神经形态工程
·
电子器件
✓ 已验证
DOI
高影响因子
DESALINATION
·
2015
·
IF 3.756
Lei Wang,Danxi Huang,Xudong Wang,Xiaorong Meng,Yongtao Lv,Xin Wang,Rui Miao
To obtain a high-performance polyvinylidene fluoride (PVDF) membrane, low-temperature thermally induced phase separation (LT-TIPS) was employed to prepare microporous flat PVDF membranes and hollow-fiber membranes using diluent mixtures of triethylphosphate and diethylene glycol monoethyl ether acetate. The membrane morphology was characterized by scanning electron microscopy (SEM) and atomic force microscopy (AFM). The results show that thermally induced phase separation (TIPS) played a more important role than nonsolvent-induced phase separation (NIPS) in determining the cross-sectional morphology of the membranes, and the surface structure was mainly affected by NIPS in a low-temperature (0 °C) coagulation bath . By increasing the temperature of the coagulation bath, different structures of membranes, such as spherulites and cellular and sponge structures, were observed. It is believed that the formation mechanism of these membranes depended on a combined NIPS and TIPS process. Wide-angle X-ray diffraction (XRD) analysis indicated that PVDF crystallized into an α-phase crystal structure for all the membranes tested. In addition, the porosity, tensile strength and filtration performance of the flat membranes were measured. On the basis of the above results, a hollow fiber membrane with highly interconnected pores and high porosity could be prepared employing LT-TIPS.
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2021
·
IF 13.273
Ze-Hui Liang,Shao-Lin Wu,Chang Liu,Hao-Cheng Yang,Seth B. Darling,Zhi-Kang Xu
Slippery lubricant-infused porous surfaces (SLIPSs) hold great promise in fields requiring adhesion resistance such as self-cleaning, anti-fouling, anti-icing, and anti-scaling. However, their road to practical application is still blocked by the complicated fabrication process and the restricted coating area. To address these challenges, we propose a new concept of endogenous SLIPS in which the porous structure grows from the solution coating of polypropylene/caprylyl methicone undergoing a thermally induced phase separation (TIPS) process. Caprylyl methicone serves as the diluent during TIPS as well as the lubricant in the SLIPS so that the coating can be fabricated in one step and unrestrictedly. The dissolution and phase separation mechanisms have been revealed by molecular dynamic simulation and in situ microscopic observation. Such SLIPSs exhibit impressive sliding property even for sticky and viscous liquids and exhibit extremely low ice adhesion in anti-icing tests.
研究领域:
材料科学
·
表面工程
·
涂层技术
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF MEMBRANE SCIENCE
·
2020
·
IF 7.183
Zhenghua Guo,Yi Yang,Shang Xiang,Xi Du,Zhenyu Cui,Benqiao He,Hong Wang,Jianxin Li,Tao Jiang
In this work, poly(vinylidene fluoride) (PVDF) flat membrane was prepared via “In-situ template-TIPS” technology using poly(vinylpyrrolidone) (PVP) as template. The membrane formation mechanism and microstructure evolution of this method were expounded for the first time. The effect of PVP content on the crystallization behavior of the dope, the microstructure, the crystallization behavior and the permeability of the membrane was investigated in detail. Interestingly, the solidification of PVP from the diluent via air-cooling at room temperature not only hindered the PVDF crystallization, but also the growth of PVP led to the formation of porous surface and eliminated the thick and dense skin layer, and thus formed the inter-connected structure and higher porosity (The maximum porosity is 88.9%). The maximum pure water flux reached as high as 3420 L m −2 h −1 . The membrane also indicated an excellent performance in rejection of bacteria and separation of “petroleum ether/water” emulsion (nearly 100%). The α crystal phase was formed for the membrane by air-cooling at room temperature. The non-isothermal crystallization kinetics revealed that PVP can act as a heterogeneous nucleating agent for PVDF crystallization and hindered the growth of PVDF crystal in three-dimension. The research presented a novel and simple idea for tailoring the microstructure of membrane via TIPS process.
研究领域:
材料科学
·
膜技术
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF POLYMER RESEARCH
·
2021
·Vol. 28
·期 8
·1-10
·
IF 3.097
Yang Bin,Wang Shu-Qing,Chen Qing-Ting,Ding Meng-Ya,Yu Yang-Nan,Pan Yang,Xia Ru,Ge Qian-Qian,Miao Ji-Bin,Qian Jia-Sheng,Chen Peng,Shi You,Tu You-Lei
Thermally-induced phase separation (TIPS) was used to fabricate polyvinylidene fluoride (PVDF) films under different quenching conditions. Temperature gradient fields were in-situ formed inside the films through varying the TIPS quenching temperature, and an enthalpy transformation method (ETM) was adopted to simulate the temperature gradient fields during the TIPS process. Our findings showed that there existed liquid–liquid phase separation (LLPS) even at higher PVDF concentration (e.g., above the monotectic point). The coexistence and competition between liquid–liquid and solid–liquid phase separations were significantly determined by the cooling rate, which helped to explain the formation mechanisms of hierarchical morphologies observed in the final TIPS films. The present work will be of substantial importance to further studies on an industrial tuning of the microstructure and performance of TIPS films through the operational parameter control.
研究领域:
材料科学
·
高分子工程
·
相变研究
✓ 已验证
DOI
高影响因子
EUROPEAN POLYMER JOURNAL
·
2020
·
IF 3.862
Qinting Chen,Bin Yang,Mengya Ding,Yang Pan,Jiasheng Qian,Zhengzhi Zheng,Bin Wu,Jibin Miao,Ru Xia,Youlei Tu,You Shi
In this work, SiO 2 @PDA nanoparticles obtained by in - situ coating polydopamine (PDA) on the surface of spherical SiO 2 nanoparticles were adopted to prepare the polyvinylidene fluoride (PVDF) composite films via thermally-induced phase separation (TIPS) method with diphenyl carbonate (DPC) as the diluent. PDA was proved to cover evenly on the surface of SiO 2 nanoparticles, which was favorable to the dispersion of hydrophilic nanoparticles in the matrix. Effect of the presence of SiO 2 @PDA nanoparticles on crystallization behavior, thermal stability, mechanical properties and hydrophilicity of the composite films was intensively investigated. Heterogeneous nucleating effect on the crystallization of PVDF coupled with elevated crystallinity was found upon the incorporation of SiO 2 @PDA without altering the crystal form of PVDF. The rigidity, tensile strength as well as thermal stability of the composite films containing SiO 2 @PDA were significantly improved in comparison to both neat film and those containing unmodified nanoparticles. In addition, the hydrophilicity of PVDF composite films’ surface was remarkably enhanced with an increasing SiO 2 @PDA content, which helped to reduce the protein adsorption of the composite films considerably. The present study would supply an insight into the fabrication of PVDF composite films with desirable performance and capabilities.
研究领域:
材料科学
·
高分子化学
·
纳米技术
·
生物医学工程
✓ 已验证
产品关联
DOI
高影响因子
POLYMER
·
2018
·
IF 3.483
Zhaoliang Cui,Yangming Cheng,Ke Xu,Juan Yue,Yue Zhou,Xiaogang Li,Qian Wang,Shi-Peng Sun,Yong Wang,Xiaozu Wang,Zhaohui Wang
Poly(vinylidene fluoride) (PVDF) membrane is widely used in water purification and wastewater treatment. In present paper, thermally induced phase separation (TIPS) was employed, and maleic acid dibutyl ester (DBM), a new diluent, was introduced for PVDF membrane preparation. Phase diagram and the effects of polymer concentration and quenching temperature on the structure, morphologies, properties, and performances of PVDF membranes were investigated. During the quenching process of PVDF/DBM system, liquid-liquid phase separation happened, and PVDF membranes with a bi-continuous structure were fabricated. What is interesting is that the liquid-liquid phase separation region was much wider than other PVDF/diluent systems. Thus, it is possible to fabricate PVDF membrane with a bi-continuous structure at high polymer concentrations, without stretching or additives. With the increase in polymer concentration and quenching temperature, mean pore size and pure water flux of the PVDF membrane decreased. Tensile stress of the prepared PVDF membranes reached to 6.18 MPa, because the wide liquid-liquid phase separation region induced a bi-continuous structure when the concentration of the PVDF membrane was at around 30%.
研究领域:
材料科学
·
环境工程
·
膜技术
✓ 已验证
产品关联
DOI
高影响因子
Applied Water Science
·
2022
·Vol. 12
·期 3
·1-11
·
IF 5.411
He Ting,Li Xiaogang,Wang Qian,Zhou Yue,Wang Xiaozu,Wang Zhaohui,Tavajohi Naser,Cui Zhaoliang
In this paper, ionic liquid 1-butyl-3-methylimidazolium tetrafluoroborate was the first time successfully utilized as single solvent in preparing the PVDF membrane with a good performance by N-TIPs method. The effects of quenching temperature and hydrophilic additive content on the morphology, permeability, and strength of the membranes were studied. All the prepared PVDF membranes were proved to be a pure β phase by FTIR and XRD, possessing a narrow pore size distribution. By adjusting quenching temperature and additive content, membranes with a flux of 383.2 L/m 2 h and concentrated pore diameter of 26 nm obtained.
研究领域:
材料科学
·
化学工程
·
膜技术
✓ 已验证
产品关联
DOI
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2024
·
IF 8.1
Chunsheng Zhao,Qiu Han,Haibo Lin,Jianmin Guan,Fu Liu
Thermally induced phase separation (TIPS) process is an appealing method for preparing poly(vinylidene fluoride) (PVDF) membranes for separation. In this work, we developed a diffusion mediated thermally induced phase separation (d-TIPS) to prepare PVDF membranes with great molecules separation performances. We investigated the thermodynamics of ternary polymer solutions including PVDF, caprolactam (CPL), and Polyethylene glycol (PEG). We controlled liquid–liquid phase separation and the CPL diffusion by adjusting the addition of PEG and molecular weight to modulate the evolution of morphology from spherulitic to bicontinuous structure. The resulting membrane was characterized by morphology, surface chemistry, tensile strength, water contact angle, and perm-selectivity. The membrane was further stretched for enhanced strength, permeance, and rejection. This work provides a fundamental understanding of the diffusion mediated thermally induced phase separation and shows the great potential of PVDF membranes in macromolecules separation.
研究领域:
材料科学
·
化学工程
·
膜技术
·
聚合物科学
✓ 已验证
产品关联
DOI
高影响因子
Advanced Composites and Hybrid Materials
·
2024
·Vol. 7
·期 6
·1-14
·
IF 23.2
Zhao Xiaotong,Du Peng,Qiu Fei,Hou Yuanlang,Lu Hanxiao,Zhang Jiemin,Geng Xiangshun,Dun Guanhua,Chen Sisi,Lei Ming,Ren Tian-Ling
The drive to deliver ever-more powerful and feature-rich organic integrated circuits has made the interface contact quality improvement—that is, the process of alleviating the hysteresis phenomenon and contact resistance of the electrical properties in organic field-effect transistors (OFETs)—a critical challenge for the organic semiconductor (OSC) microelectronics industry. The use of blends of OSCs and insulating binding polymers has offered a breakthrough to circumvent these limitations. Here, we introduced a novel method for preparing high-performance OFETs based on a direct-writing inkjet printing (DWIP) blend composed of 6,13-bis(triisopropylsilylethinyl) pentacene (TIPS-pentacene) and poly(methyl methacrylate) (PMMA). The small molecular weight of PMMA imparted significantly superior crystallization of small-molecule OSCs, and the OFETs exhibited better electrical performance than other comparative conditions. The crystallization and characteristics improved because of two mechanisms: First, the PMMA delivered superior mechanical strength, stability, and improved film uniformity and created a more uniform interface that decreased the charge accumulation, thereby alleviating the hysteresis and contact resistance. Second, combined with DWIP technology and thanks to the advantages of horizontal solution shearing and spatially restricted domains, the blends contributed to solute draw and thus handled mass transport more efficiently and controllably. The proposed method provides attractive properties for industrial applications.
研究领域:
材料科学
·
电子工程
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
Journal of Materials Chemistry C
·
2021
·Vol. 9
·期 17
·5621-5627
·
IF 7.393
Huihong Jiang,Boyu Peng,Shuang Liu,Jie Ren,Weitao Yang,Chengce Lin,Ruihan Wu,Hongzheng Chen,Hanying Li
Organic single crystals, with regular molecular packing and fewer structural defects, have presented record-high carrier mobility of various organic semiconductor materials, making them ideal charge-transport media for flexible devices. However, compared with organic amorphous/polycrystalline films, organic single crystals are more fragile. To utilize high-quality organic single crystals in flexible devices, the diverse response (cracks, delamination) of single crystals to bending strain should be meticulously explored, as well as the associated effects on transistor performance. Here, flexible organic field-effect transistors (OFETs) fabricated from aligned, ribbon-like single crystals of bis(triisopropylsilylethynyl)pentacene (TIPS-pentacene) are studied in different bending scenarios. With increasing tensile or compressive bending strain, the single crystal will crack or delaminate. The cracks are prone to appear faceted with a direction along the crystal ribbons, parallel to the crystallographic planes of the dense molecular packing. While interestingly, devices exhibit negligible decline in mobility even if the crystal surface has obvious cracks, which is ascribed to the intact charge transport channel. Moreover, devices show superior stability after 1000 consecutive bending cycles or keeping bent for 20 days. As such, this work confirms the potential of organic single crystals being applied to flexible transistor devices with good stability as well as high performance.
研究领域:
材料科学
·
电子工程
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）