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Understanding rate‐limiting processes for the sublimation of small molecule organic semiconductors 
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下载免费PDF全文 Nathan T. Morgan Yi Zhang Erich J. Molitor Bruce M. Bell Russell J. Holmes E. L. Cussler 《American Institute of Chemical Engineers》2014,60(4):1347-1354
Organic small molecules continue to gain attention for application in light‐emitting devices in displays and solid‐state lighting. The purification of these materials by sublimation represents a critical obstacle for their high throughput processing. In this work, we find that the purification of the archetypical hole‐transporting material N,N′‐bis(naphthalen‐1‐yl)‐N,N′‐bis(phenyl)‐benzidine (α‐NPD) is controlled by a combination of viscous flow, Knudsen diffusion, and physical vapor deposition. In contrast with other commercially practiced sublimations, steps like diffusion within the solid feed, desorption from the feed particle surface, and mass transfer within the bed of feed particles, do not significantly affect the sublimation rate. This work provides guidelines for the large‐scale purification of organic semiconductor materials, and possibly for a broader range of high value small molecule specialty materials. © 2014 American Institute of Chemical Engineers AIChE J, 60: 1347–1354, 2014 相似文献
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Ariel J. Ben-Sasson Michael Greenman Yohai Roichman Nir Tessler 《Israel journal of chemistry》2014,54(5-6):568-585
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Afreen Sultana Mina Zare Hongrong Luo Seeram Ramakrishna 《International journal of molecular sciences》2021,22(21)
Decades of intense scientific research investigations clearly suggest that only a subset of a large number of metals, ceramics, polymers, composites, and nanomaterials are suitable as biomaterials for a growing number of biomedical devices and biomedical uses. However, biomaterials are prone to microbial infection due to Escherichia coli (E. coli), Staphylococcus aureus (S. aureus), Staphylococcus epidermidis (S. epidermidis), hepatitis, tuberculosis, human immunodeficiency virus (HIV), and many more. Hence, a range of surface engineering strategies are devised in order to achieve desired biocompatibility and antimicrobial performance in situ. Surface engineering strategies are a group of techniques that alter or modify the surface properties of the material in order to obtain a product with desired functionalities. There are two categories of surface engineering methods: conventional surface engineering methods (such as coating, bioactive coating, plasma spray coating, hydrothermal, lithography, shot peening, and electrophoretic deposition) and emerging surface engineering methods (laser treatment, robot laser treatment, electrospinning, electrospray, additive manufacturing, and radio frequency magnetron sputtering technique). Atomic-scale engineering, such as chemical vapor deposition, atomic layer etching, plasma immersion ion deposition, and atomic layer deposition, is a subsection of emerging technology that has demonstrated improved control and flexibility at finer length scales than compared to the conventional methods. With the advancements in technologies and the demand for even better control of biomaterial surfaces, research efforts in recent years are aimed at the atomic scale and molecular scale while incorporating functional agents in order to elicit optimal in situ performance. The functional agents include synthetic materials (monolithic ZnO, quaternary ammonium salts, silver nano-clusters, titanium dioxide, and graphene) and natural materials (chitosan, totarol, botanical extracts, and nisin). This review highlights the various strategies of surface engineering of biomaterial including their functional mechanism, applications, and shortcomings. Additionally, this review article emphasizes atomic scale engineering of biomaterials for fabricating antimicrobial biomaterials and explores their challenges. 相似文献
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Lizhang Chen Weiying Zhang Yuefeng Dong Qiuyue Chen Wanjun Ouyang Xiao Li Xiaoguang Ying Jianying Huang 《大分子材料与工程》2020,305(3)
With the development of alternatives to traditional fossil energy and the rise of wearable technology, flexible energy storage devices have attracted great attention. In this paper, a polyaniline/poly(acrylamide‐sodium acrylate copolymer) hydrogel (PASH) with high flexibility and excellent electrochemical properties for flexible electrodes is fabricated by freeze‐thaw‐shrink treatment of a highly water‐absorptive hydrogel, together with in‐situ polymerization of aniline at a low aniline concentration (0.1 mol L?1). The PASH exhibits a conductivity of 4.05 S m?1 and an elongation at break of 1245%. The freeze‐thaw‐shrink treatment greatly improves the electrochemical performance and stability of the conductive PASH. The area specific capacitance of PASH reaches 849 mF cm?2 and the capacitance maintains 89% after 1000 galvanostatic charge–discharge cycles. All the raw materials are conventional industrialized materials and no additional templating agent is needed during the entire synthesis process. This study provides a cost‐efficient approach for the fabrication of conductive polymer hydrogels, which has a broad application prospect in flexible energy storage electronic devices. 相似文献
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Na Du Fangfu Ye Jing Sun Kai Liu 《Chembiochem : a European journal of chemical biology》2022,23(6):e202100416
Natural proteins are essential biomacromolecules that fulfill versatile functions in the living organism, such as their usage as cytoskeleton, nutriment transporter, homeostasis controller, catalyzer, or immune guarder. Due to the excellent mechanical properties and good biocompatibility/biodegradability, natural protein-based biomaterials are well equipped for prospective applications in various fields. Among these natural proteins, stimuli-responsive proteins can be reversibly and precisely manipulated on demand, rendering the protein-based biomaterials promising candidates for numerous applications, including disease detection, drug delivery, bio-sensing, and regenerative medicine. Therefore, we present some typical natural proteins with diverse physical stimuli-responsive properties, including temperature, light, force, electrical, and magnetic sensing in this review. The structure-function mechanism of these proteins is discussed in detail. Finally, we give a summary and perspective for the development of stimuli-responsive proteins. 相似文献
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Natalie Stingelin 《Polymer International》2012,61(6):866-873
The physical organisation, from the molecular to the macroscale, of functional organic matter such as polymer semiconductors can profoundly affect the properties and features of the resulting architectures and their consequent performance when used as active layers in organic optoelectronic devices, including organic thin‐film field‐effect transistors, organic light‐emitting diodes or organic photovoltaic cells. Here, we present a survey on the principles of structure development from the liquid phase of this interesting and broad class of materials with focus on how to manipulate their phase transformations and solid‐state order to tailor and manipulate the final ‘morphology’ towards technological and practical applications. Copyright © 2012 Society of Chemical Industry 相似文献
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Mário C. Vebber Benjamin King Callum French Mathieu Tousignant Bahar Ronnasi Chloé Dindault Guillaume Wantz Lionel Hirsch Jaclyn Brusso Benoît H. Lessard 《加拿大化工杂志》2023,101(6):3019-3031
Silicon phthalocyanines (R2-SiPcs) are a family of promising tunable materials for organic electronic applications. We report the chemistry of the synthesis of axially substituted fluorinated SiPcs (tb-Ph)2-FxSiPc (where X = 0, 4, 8, or 16) and explore how the degree of fluorination effects optical and electronic properties. A new treatment with boron trichloride was included to obtain Cl2-FXSiPcs from F2-FXSiPcs, activating the axial position for further functionalization. We observed that as the degree of fluorination increased, so did the electron affinity of the compounds, leading to a drop in frontier orbital levels, as measured by electrochemistry and ultraviolet photoelectron spectroscopy (UPS). The deeper energy levels enabled successful (tb-Ph)2-F4SiPc and poly [[6,7-difluoro[(2-hexyldecyl)oxy]-[5,8-quinoxalinediyl]-2,5-thiophenediyl]] (PTQ10) blends for organic photovoltaics and photodetectors. All four compounds were incorporated in organic thin-film transistors (OTFTs), where the degree of fluorination influenced device operation, changing it from p-type conduction for (tb-Ph)2-F0SiPc, to ambipolar for (tb-Ph)2-F4SiPc, and n-type for (tb-Ph)2-F8SiPc and (tb-Ph)2-F16SiPc. The OTFT devices made with (tb-Ph)2-F16SiPc achieved a low average threshold voltage of 7.0 V in N2 and retained its n-type mobility when exposed to air. 相似文献
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Eric Daniel Głowacki Gundula Voss Lucia Leonat Mihai Irimia-Vladu Siegfried Bauer Niyazi Serdar Sariciftci 《Israel journal of chemistry》2012,52(6):540-551
We describe the history of indigo dye and its derivative Tyrian purple, from their roles in the ancient world to recent research showing the semiconducting properties of indigoids. Indigoids are natural dyes that have been produced for centuries, and indigo is currently the most produced dye worldwide. Herein we review the history of these materials, their chemistry and physical properties, and their semiconducting characteristics in the solid state. Due to hydrogen bonding and π-stacking, indigo and Tyrian purple form highly-ordered crystalline thin films. Such films have been used to fabricate high-performance organic field-effect transistors with ambipolar charge transport, as well as complementary-like circuits. Mobility values were found to be in the range of 10−2–0.4 cm2/Vs. With performance on par with the best available organic semiconductors, indigoids demonstrate the potential of sustainable electronics based on biodegradable and biocompatible materials. 相似文献
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Giampiero Pietrocola Davide Campoccia Chiara Motta Lucio Montanaro Carla Renata Arciola Pietro Speziale 《International journal of molecular sciences》2022,23(11)
The use of indwelling medical devices has constantly increased in recent years and has revolutionized the quality of life of patients affected by different diseases. However, despite the improvement of hygiene conditions in hospitals, implant-associated infections remain a common and serious complication in prosthetic surgery, mainly in the orthopedic field, where infection often leads to implant failure. Staphylococcus aureus is the most common cause of biomaterial-centered infection. Upon binding to the medical devices, these bacteria proliferate and develop dense communities encased in a protective matrix called biofilm. Biofilm formation has been proposed as occurring in several stages—(1) attachment; (2) proliferation; (3) dispersal—and involves a variety of host and staphylococcal proteinaceous and non-proteinaceous factors. Moreover, biofilm formation is strictly regulated by several control systems. Biofilms enable staphylococci to avoid antimicrobial activity and host immune response and are a source of persistent bacteremia as well as of localized tissue destruction. While considerable information is available on staphylococcal biofilm formation on medical implants and important results have been achieved on the treatment of biofilms, preclinical and clinical applications need to be further investigated. Thus, the purpose of this review is to gather current studies about the mechanism of infection of indwelling medical devices by S. aureus with a special focus on the biochemical factors involved in biofilm formation and regulation. We also provide a summary of the current therapeutic strategies to combat biomaterial-associated infections and highlight the need to further explore biofilm physiology and conduct research for innovative anti-biofilm approaches. 相似文献
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Despite progress which has been made in recent years in the field of cell-based therapies or cell scaffolds for cartilage regeneration, a lot of work still needs to be done. Scaffolds remain a great base for tissue regeneration. However, proper implantation procedures or post-treatment still await development.
In this review we summarize paths of cartilage treatment, especially focusing on cell scaffold design and manufacture. As well as the advantages and disadvantages of available or investigated methods and materials, especially focusing on cartilage scaffold design. We show the most promising directions and barriers in the creation of healthy tissue. 相似文献
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游一中 《精细与专用化学品》1999,7(22):32-34
本文简要介绍了我国医用气雾剂的分类组成,国外已用于医用气雾剂的各种CFCs替代品、替代技术和装置,并对我国启动替代进程提出五点建议。 相似文献
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Drew Evans 《Polymer International》2018,67(4):351-355
For almost four decades conducting polymers (CPs) have maintained the interest of the global scientific community. This interest arises from the unique blend of properties that these materials possess: tuneable electrical properties combined with mechanical flexibility of traditional polymers. In more recent times the broader investigation of CP properties and behaviour has led to new potential applications, such as photovoltaic and bioelectronic devices. The promise of CPs is considerable, yet to date they have had limited penetration into the commercial and industrial sectors. This perspective article highlights some of the challenges and opportunities ahead as CPs translate from the research sector into commercial products. In particular is the need to study in depth the manufacturing process(es) of CPs and how they relate to existing or emerging industry. © 2018 The Author. Polymer International published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry. 相似文献
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Gang Qian Nathan T. Morgan Russell J. Holmes E. L. Cussler D. Wayne Blaylock Robert D. J. Froese 《American Institute of Chemical Engineers》2016,62(3):861-867
Purification of large organic molecules in a tubular sublimator occurs by a combination of laminar flow, Knudsen diffusion, and volume diffusion. For laminar flow, the amount purified per area per driving force varies with pd2, where p is pressure and d is tube diameter. For Knudsen diffusion, it varies with d and is not a function of pressure. For volume diffusion, it is constant, consistent with experiment. This volume diffusion mechanism may offer an alternative explanation to slip flow for dilute gas transport of both organic semiconductors and common low molecular weight gases. © 2015 American Institute of Chemical Engineers AIChE J, 62: 861–867, 2016 相似文献
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Yuanyuan Chen Luke M. Geever John A. Killion John G. Lyons Clement L. Higginbotham 《Polymer-Plastics Technology and Engineering》2016,55(10):1057-1075
Poly (lactic acid) is considered to be a promising alternative to petroleum-based polymers due to its renewability, biodegradability, biocompatibility, and good mechanical properties. Because of the high cost, the applications of poly (lactic acid) were limited to the medical field. Over the past decade, improvements in polymerization allow the economical mass production of high molecular weight poly (lactic acid). Therefore, the applications of poly (lactic acid) have recently spread to domestic, commercial packaging, and textile applications. This review outlines the chemical, thermal characteristics of poly (lactic acid) and discusses the use of poly (lactic acid) in medical applications such as sutures, stents, drug carrier, orthopaedic devices, scaffolds, as well as commercial applications in textile and packaging fields with superior properties such as high wicking performance, good dyeability, antibacterial feature, good ultraviolet resistance, high water vapor transmission rates, shrink wrapping, and dead fold property. While the drawbacks of poly (lactic acid) utilized in these fields are also discussed. It is clear that the advantages of using poly (lactic acid) outlined in this review will ensure that the market for poly (lactic acid) products will continue to expand. 相似文献
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The phase segregation as a result of mixing organic semiconductors with polymeric additives has been reported as an intriguing avenue to optimize semiconductor crystal microstructure, active layer composition and charge carrier transport. In this work, we report the mixing of organic semiconductor 6,13-bis(triisopropylsilylethynyl) pentacene (TIPS pentacene) with poly(butylacrylate) as a polymer additive to control the semiconductor crystal growth and morphology. The incorporation of poly(butylacrylate) induces a vertical phase segregation but a more predominant lateral phase segregation with TIPS pentacene. Along with a solvent vapor annealing technique, poly(butylacrylate) evenly distributes the semiconductor nuclei on the polymer matrix, and results in organic crystal with enlarged grain width. In addition, the randomized crystal growth of TIPS pentacene has been significantly reduced, giving rise to a 25-fold decrease in misorientation angle. The bottom-gate, top-contact thin film transistors with the poly(butylacrylate)/TIPS pentacene mixture as the active layer demonstrated an improved hole mobility of 0.11 cm2/Vs. We believe the phase segregation induced by the poly(butylacrylate) polymer as well as the solvent vapor annealing method as reported in this work can be facilely replicated on other organic semiconductors to realize high performance organic electronic device applications. 相似文献
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Compared to organic light-emitting diodes, solid-state light-emitting electrochemical cells (LECs) exhibit advantages of simple device structures, low operation voltages, and compatibility with air-stable metal electrodes. Since the first demonstration of white LECs in 1997, the cells have been studied extensively, due to their potential applications in solid-state lighting. This article reviews the development of white LECs based on conjugated polymers and cationic transition metal complexes. Important achievements of each work on white LECs are highlighted. Finally, the outlook for future development of white LECs is discussed. 相似文献
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Organic electroluminescent devices recently have been focus of attention. Since the first demonstrations in this field, rapid developments have occurred in the usage of organic polyaromatic compounds and their derivatives for the purpose of multi-layer structures, multi-color, and full-color organic light-emitting diode displays. In the part-1 of the present short review, recent technical developments in the preparation and structure of organic light emitting diodes with special attention to organic emitters involving polyaromatic kernels have been considered. 相似文献