antisolvent method

  • 文章类型: Journal Article
    在过去的几年里,具有独特物理性质的铁电纳米材料在现代电子学中的应用潜力在很大程度上凸显出来。然而,制造无机铁电纳米材料相对具有挑战性,这是一个取决于高温下真空气氛的过程。作为无机铁电纳米材料的重要补充,分子铁电体纳米材料鲜有报道。在这里,低成本的室温反溶剂方法用于合成独立式2D有机-无机杂化钙钛矿(OIHP)铁电纳米片(NSs),也就是说,(CHA)2PbBr4NSs(CHA=环己基铵),平均横向尺寸为357.59nm,厚度为10至70nm。该方法显示出高可重复性并产生具有优异结晶度的NSs。此外,可以使用压电响应力显微镜(PFM)清楚地可视化和操纵单个NS中的铁电畴。域切换和PFM切换光谱表明NS具有强大的面内铁电性。这项工作不仅介绍了一个可行的,低成本,和可扩展的制备分子铁电NSs的方法也促进了分子铁电纳米材料的研究。
    Over the past years, the application potential of ferroelectric nanomaterials with unique physical properties for modern electronics is highlighted to a large extent. However, it is relatively challenging to fabricate inorganic ferroelectric nanomaterials, which is a process depending on a vacuum atmosphere at high temperatures. As significant complements to inorganic ferroelectric nanomaterials, the nanomaterials of molecular ferroelectrics are rarely reported. Here a low-cost room-temperature antisolvent method is used to synthesize free-standing 2D organic-inorganic hybrid perovskite (OIHP) ferroelectric nanosheets (NSs), that is, (CHA)2PbBr4 NSs (CHA = cyclohexylammonium), with an average lateral size of 357.59 nm and a thickness ranging from 10 to 70 nm. This method shows high repeatability and produces NSs with excellent crystallinity. Moreover, ferroelectric domains in single NSs can be clearly visualized and manipulated using piezoresponse force microscopy (PFM). The domain switching and PFM-switching spectroscopy indicate the robust in-plane ferroelectricity of the NSs. This work not only introduces a feasible, low-cost, and scalable method for preparing molecular ferroelectric NSs but also promotes the research on molecular ferroelectric nanomaterials.
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  • 文章类型: English Abstract
    OBJECTIVE: The aim of the study to study of physical, mechanical and biocompatible properties of the matrices manufactured by antisolvent 3D printing from the solutions of polylactide-co-glycolide in tetraglycol.
    METHODS: Three-dimensional scaffolds were made from a solution of polylactide-co-glycolide mixed with tetraglycol using antisolvent 3D printing. The elastic properties and the structure of the obtained matrices were studied. MTT-test and staining with PKH-26, Calcein-AM, DAPI with subsequent fluorescence microscopy were used to study biological properties.
    RESULTS: The three-dimensional scaffolds had good mechanical properties. Young\'s modulus value was 18±2 MPa, tensile strength was 0.43±0.05 MPa. The relative survival rate of cells after the first day was 99.58±2.28%, on the 14th day - 98.14±2.22%. The structure of the scaffold promoted cell adhesion and spreading on its surface.
    CONCLUSIONS: The polylactide-co-glycolide matrices produced by antisolvent printing have high porosity, biocompatibility and good mechanical properties. It is allowed to use them in the future as a basis for personalized constructions for the replacement of extensive bone defects of the maxillofacial region.
    UNASSIGNED: Изучение физико-механических и биосовместимых свойств матриксов, полученных с помощью антисольвентной 3D-печати из растворов полилактогликолида в тетрагликоле.
    UNASSIGNED: Из раствора полилактогликолида, смешанного с тетрагликолем, с помощью 3D-принтинга изготавливали трехмерные скаффолды методом антисольвентной печати. Проводили исследования прочностных и упругих свойств, структуры полученных матриксов. Для изучения биологических свойств использовали MTT-тест и окрашивание витальными красителями PKH-26, кальцеин-АМ, DAPI с последующей флуоресцентной микроскопией.
    UNASSIGNED: Трехмерные скаффолды обладали выраженными прочностными свойствами. Значение модуля Юнга 18±2 МПа, прочность на разрыв 0,43±0,05 МПа. Относительная выживаемость клеток после 1-х суток составила 99,58±2,28%, на 14-е сутки — 98,14±2,22%. Структура скаффолдов способствовала адгезии и распластыванию клеток на их поверхности.
    UNASSIGNED: Изготовленные с помощью антисольвентной печати полилактогликолидные матриксы обладают высокой пористостью, биосовместимостью и выраженными прочностными свойствами. В перспективе это позволяет рассматривать их в качестве основы персонализированных конструкций для замещения обширных костных дефектов челюстно-лицевой области.
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  • 文章类型: Journal Article
    二维(2D)有机-无机钙钛矿由于其出色的光电特性,在制造下一代光电探测器方面具有巨大的潜力,但是它们的利用遇到了由薄膜的不利连续性引起的各向异性载流子传输的瓶颈。我们提出了一种在与ZnOQD氯仿反溶剂相关的大气条件下制造0DZnO量子点(QD)/2D(PEA)2PbI4纳米片混合光电探测器的简便方法。从反溶剂中获利,钙钛矿薄膜的均匀形态是由于显著加速的成核位点形成和晶粒生长速率而获得的,和ZnO量子点均匀地装饰(PEA)2PbI4纳米片的表面,自发钝化钙钛矿上的缺陷,并通过匹配良好的能带结构增强载流子分离。通过改变ZnOQD浓度,光电探测器的Ion/Ioff比从78.3急剧上升到1040,同时观察到归一化探测率增加了12倍。此外,钙钛矿晶粒的团聚受退火温度的控制,并且在120°C的相对低温下制造的光电探测器在没有任何封装的情况下在空气条件下进行50个循环测试后表现出优异的稳定性。
    Two-dimensional (2D) organic-inorganic perovskites have great potential for the fabrication of next-generation photodetectors owing to their outstanding optoelectronic features, but their utilization has encountered a bottleneck in anisotropic carrier transportation induced by the unfavorable continuity of the thin films. We propose a facile approach for the fabrication of 0D ZnO quantum dot (QD)/2D (PEA)2PbI4 nanosheet hybrid photodetectors under the atmospheric conditions associated with the ZnO QD chloroform antisolvent. Profiting from the antisolvent, the uniform morphology of the perovskite thin films is obtained owing to the significantly accelerated nucleation site formation and grain growth rates, and ZnO QDs homogeneously decorate the surface of (PEA)2PbI4 nanosheets, which spontaneously passivate the defects on perovskites and enhance the carrier separation by the well-matched band structure. By varying the ZnO QD concentration, the Ion/Ioff ratio of the photodetectors radically elevates from 78.3 to 1040, and a 12-fold increase in the normalized detectivity is simultaneously observed. In addition, the agglomeration of perovskite grains is governed by the annealing temperature, and the photodetector fabricated at a relatively low temperature of 120 °C exhibits excellent stability after a 50-cycle test in the air condition without any encapsulation.
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  • 文章类型: Journal Article
    作为纳米药物输送系统(NDS)之一,药物纳米晶体表现出优异的抗癌作用。最近,药物纳米晶体和小分子游离药物的内化机制和亚细胞定位的差异引起了人们的广泛关注。在本文中,紫杉醇(PTX)作为模型抗癌药物直接用4-氯-7-硝基-1,2,3-苯并恶二唑(NBD-Cl)标记(药物-荧光团缀合物Ma等人。(2016)和Wang等人。(2016)[1,2](PTX-NBD))。通过PTX与NBD-Cl的亲核取代反应合成了PTX-NBD,并通过荧光表征,XRD,ESI-MS,和FT-IR分析。随后,用反溶剂法制备立方体形PTX-NBD纳米晶体,然后对SPC和MPEG-DSPE进行表面功能化。获得的特定形状的PTX-NBD@PC-PEGNC具有~50nm的流体动力学粒径,优异的胶体稳定性,和高达64%的高载药量。此外,与游离的PTX-NBD和具有SPC和MPEG-DSPE(PTX-NBD@PC-PEGNS)表面功能化的球形PTX-NBD纳米晶体相比,PTX-NBD@PC-PEGNC显着降低了突释,并提高了细胞摄取效率和体外癌细胞杀伤能力。一句话,这项工作突出了基于药物-荧光团缀合物的theranostic前药纳米晶体用于细胞成像和化疗的潜力。
    As one of nanomedicine delivery systems (NDSs), drug nanocrystals exhibited an excellent anticancer effect. Recently, differences of internalization mechanisms and subcellular localization of both drug nanocrystals and small molecular free drug have drawn much attention. In this paper, paclitaxel (PTX) as a model anticancer drug was directly labeled with 4-chloro-7-nitro-1, 2, 3-benzoxadiazole (NBD-Cl) (a drug-fluorophore conjugate Ma et al. (2016) and Wang et al. (2016) [1,2] (PTX-NBD)). PTX-NBD was synthesized by nucleophilic substitution reaction of PTX with NBD-Cl in high yield and characterized by fluorescence, XRD, ESI-MS, and FT-IR analysis. Subsequently, the cube-shaped PTX-NBD nanocrystals were prepared with an antisolvent method followed by surface functionalization of SPC and MPEG-DSPE. The obtained specific shaped PTX-NBD@PC-PEG NCs had a hydrodynamic particle size of ∼50nm, excellent colloidal stability, and a high drug-loading content of ∼64%. Moreover, in comparison with free PTX-NBD and the sphere-shaped PTX-NBD nanocrystals with surface functionalization of SPC and MPEG-DSPE (PTX-NBD@PC-PEG NSs), PTX-NBD@PC-PEG NCs remarkably reduced burst release and improved cellular uptake efficiency and in vitro cancer cell killing ability. In a word, the work highlights the potential of theranostic prodrug nanocrystals based on the drug-fluorophore conjugates for cell imaging and chemotherapy.
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