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81.
The micellization behavior of amphiphiles is a well-analyzed physicochemical phenomenon, which can be easily influenced by various parameters such as pressure, temperature, and the presence of different additives. Inorganic salts are able to affect the thermodynamic and surface properties of amphiphiles significantly. The effect of a series of salts as additives namely lithium chloride (LiCl), potassium chloride (KCl), sodium chloride (NaCl), sodium bromide (NaBr), and sodium iodide (NaI) on interfacial chemical characteristics of the surface-active ionic liquid (SAIL) 1-dodecyl-3-methylimidazolium chloride [C12mim][Cl] in aqueous solution were examined through conductance, surface tension, fluorescence, 1H NMR, and dynamic light scattering measurements. The interfacial and thermodynamic parameters of all investigated SAIL-salt systems were evaluated from surface tension and conductance measurements, respectively. A detailed analysis of the microenvironment of the micelles and the size of the micelles was done using 1H NMR and dynamic light scattering measurements. 相似文献
82.
透明玻璃和树脂材料应用广泛,是未来世界重要的构成元素。但这些材料表面常易发生水蒸气凝结起雾现象,不但降低了材料本身的透明度,影响相关产品的使用,还会给设备的运行安全带来隐患。因此,如何防雾逐渐引起研究人员和产业届的关注。常见的防雾技术有自动擦拭、热力防雾、表面涂层等。其中,具有主动防雾性能的超亲水表面涂层技术在施工简便性、持续防护性及运行维护成本的经济性等方面具有独特优势,是最有发展潜力的防雾技术。详细介绍了超亲水防雾表面的设计和制造技术的最新进展,从起雾现象的机制出发,介绍了水滴的形核和生长,并由此引出超亲水表面的防雾机理。分类介绍了由不同制备方法所得到的超亲水防雾表面,重点综述了近年来超亲水防雾涂层技术的研究进展,包括有机超亲水涂层、无机超亲水涂层与有机无机杂化超亲水涂层。针对各种形式的超亲水涂层技术,分别从涂层的亲水性、防雾性、耐久性及制备膜层的结构与性能之间的关系等方面进行了归纳。最后,根据超亲水防雾表面在不同领域的实际应用,对其未来的发展进行了展望。 相似文献
83.
以氯桥二聚体[Ir(dfppy)2(μ-Cl2)]2、1-苯基-1,3-丁二酮为原料合成了一种铱磷光配合物Ir(dfppy)2(phbudio),产率86.0%,并通过元素分析、核磁共振谱、质谱和红外光谱表征确认了目标产物的化学结构。通过紫外-可见吸收以及荧光光谱对其光物理性质进行测试,其常温最大发射位于522 nm处,显示发射强烈的绿光,初步推测该铱磷光配合物发射可能来自金属铱到环金属配体和辅助配体的电荷转移(MLCT)跃迁。 相似文献
84.
Ana Carolina Rodríguez-Negrette María José Rodríguez-Batiller Victor Alonso García-Londoño Virginia Borroni Roberto Jorge Candal María Lidia Herrera 《Journal of the American Oil Chemists' Society》2020,97(11):1215-1228
Physical chemical properties of cupuassu fat were modified by dry fractionation. Stearin and olein fractions were obtained at 29, 26, and 24 °C. Polymorphic behavior of unfractionated cupuassu fat (UCF) and its fractions were studied in situ by small-angle (SAXS) and wide-angle (WAXS) X-ray scattering using synchrotron light. Polymorphic transitions were followed in real time tempering samples with a thermal cycle. For UCF, the main polymorphic form crystallized under selected conditions was the β’2. α and β’1-forms appeared in trace amounts. β2-form was obtained after storage at 25 °C for 3 months. Stearins obtained at 26 (S-26) and 24 °C (S-24) showed a similar polymorphic behavior. However, S-26 with improved physical properties might be more suitable for chocolate production or as a trans-fat alternative than UCF. Stearin fraction obtained at 29 °C (S-29) had a complex polymorphic behavior. The α-form was the first polymorphic form detected followed by β’2-form. There was a polymorphic transition from α to β’1-form but no transition between β’-forms. They were independent to each other showing fractionation in two different solid solutions. Increased contents of the triacylglycerols (TAG) SOA and SOB together with lower contents of SOO compared to UCF led to co-crystallization because there was no complete compatibility among all TAG present in S-29. β1-form crystallized after storage forming crystals with a double-layer arrangement and a characteristic morphology. This form could be useful for accelerating crystallization process in melted liquid systems. 相似文献
85.
Ozcan Koysuren 《应用聚合物科学杂志》2020,137(14):48524
It was aimed to prepare polyaniline (Pani) composites, including silicon carbide (SiC) nanofibers doped with iron (Fe) ions. The Fe-doping of SiC was performed to enhance the photocatalytic activity of the composites through the separation of photoexcited mobile charge carriers. For comparison purposes, Pani composites were also prepared with undoped SiC nanofibers. The composite samples were characterized by FTIR, XRD, SEM, EDX, and UV–Vis spectroscopies. Experiments on photocatalytic degradation of methylene blue under ultraviolet light irradiation revealed that Pani/SiC-Fe composites exhibited higher photocatalytic activity when compared with Pani/SiC composites. Almost 22% dye removal was obtained within 300 min with the Pani composite, containing 15 wt.% SiC-Fe. FTIR, XRD, SEM, EDX, and UV–Vis spectroscopies demonstrated that SiC nanofibers were successfully doped with iron ions and incorporated into the polyaniline matrix. The original aspect of this study was to research the photocatalytic activity of polyaniline composites containing Fe-doped SiC nanofibers. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020 , 137, 48524. 相似文献
86.
《Journal of the European Ceramic Society》2020,40(12):4323-4331
Reducing the viscosity of high solid-loading ceramic suspensions and controlling the resolution of ceramic green parts produced by digital light processing (DLP) 3D printing are two important concerns in the ceramic additive manufacturing industry. The presence of ceramic particles within a photopolymerizable system leads to light scattering that reduces the resolution of the ceramic green scaffolds. This study introduced a graphite additive to solve these problems and focused on the effects of graphite concentration on the viscosity, curing behaviour and scaffold fabrication of β-TCP ceramic suspensions. As a result, it was found that an appropriate addition of graphite reduced the viscosity of the ceramic suspensions, and the light scattering decreased with the increase of graphite concentration. Both the cure depth (Cd) and excess width (Cex) also decreased with the increase of graphite concentration. But, graphite has a larger effect on the width curing than depth curing. 相似文献
87.
88.
In this study, reduced graphene oxide (RGO)‐Cd(1 ? x)ZnxS nanocomposites have been synthesized with the solvothermal method in one pot. Moreover Pt, Ru, and Rh nanoparticles have been loaded on the RGO‐Cd(1 ? x)ZnxS nanocomposites as cocatalysts with the aim of increasing the photocatalytic (PC) performance for hydrogen evolution reaction. The structure of Cd(1 ? x)ZnxS blend transforms from cubic to hexagonal structure during the PC hydrogen evolution reaction (PCHER) at the room temperature. This photo‐induced phase transformation (PIPT) enhances not only the hydrogen evolution rate, but also the stability of the photocatalysts. Interestingly, RGO triggers the PIPT process only during the PCHER under solar light illumination. On the other hand, the loading of Pt, Ru, and Rh cocatalysts do not affect the PIPT process. However, they enhance the PC and photoelectrochemical (PEC) hydrogen production activity of RGO‐Cd(1 ? x)ZnxS photocatalyst. PEC performance increases about 5.5 times when Pt (5%) and RGO are added to the Cd0.60Zn0.40S catalyst. RGO‐Cd0.60Zn0.40S including 1.5% Rh photocatalyst reaches a remarkable PC hydrogen production rate of 135 μmolh?1 with QE of 23.3% at 460 nm. Therefore, Rh cocatalyst appears as a good alternative to Pt. 相似文献
89.
双面板非金属孔内渗油是PCB感光阻焊制程中最常见的品质缺陷之一。就双面板非金属孔内渗油的品质问题进行了研究,设计试验对各影响因素进行分析,确定双面板非金属孔内渗油的根本原因及改善方向。 相似文献
90.
A facile strategy for the introduction of tert-butyl and hexyl chains to the indolo[3,2,1-jk]carbazole scaffold is presented. With these building blocks six materials based on three different 4,4′-bis(N-carbazolyl)-1,1-biphenyl derivatives with varying degree of planarization were prepared. Characterization of the materials showed that the alkyl chains have only minor effects on the photophysical properties of the compounds. In contrast, thermal robustness towards decomposition and electrochemical stability are increased by the introduced alkyl chains. Detailed investigation of the solubility in five different solvents revealed that the incorporation of the alkyl chains increases the solubility significantly. The increased solubility of the materials allowed the application as host materials in red, green and sky-blue solution processed phosphorescent organic light emitting diodes. Hence, this work presents the first solution processed light emitting devices based on the indolo[3,2,1-jk]carbazole scaffold. 相似文献