光刻蚀法制备水凝胶微图案及其应用

采用光刻技术, 通过光引发单体聚合, 在硅烷化破片表面原位制备水凝胶微图案. 该法简便易行, 无需复杂的仪器设备和操作过程, 且所制微图案具有较好的稳定性. 通过细胞微图案化和液滴微结构制备展示了该技术的实用性和潜在的应用方向.     

具有规整结构和高强度的水凝胶研究进展

人造水凝胶普遍存在结构不规整的问题,即交联点无序性分布和链节长短不一。这就导致人造水凝胶存在机械性能差、响应速度慢、溶胀之后回复性不好等缺点,大大限制了其在生物医学和工业等领域的应用范围。然而,生物凝胶却普遍具有规整的微结构和优异的性能。制备具有规整结构的水凝胶已经成为一个具有挑战性的重要课题。本文综述了制备具有规整结构的高强度水凝胶的研究进展。     

基于热模塑法制备HDPE仿生超疏水表面

研究了热模塑法在制备超疏水高密度聚乙烯(HDPE)膜中的应用。以高岭土增强的聚二甲基硅氧烷(PDMS)为软模板,采用热模塑技术,将荷叶表面的微结构信息复制到HDPE膜表面。接触角测量结果显示,10%掺杂量的PDMS软模板复制得到的HDPE膜表面,与水的接触角高达156°,呈现超疏水性。扫描电镜照片显示,PDMS软模板具有与荷叶表面互补的"负型结构",而HDPE膜表面则具有与荷叶类似的微米—纳米复合粗糙结构。此法无需溶剂,可推广制备其它热塑性高聚物的超疏水表面。     

基于静态呼吸图技术的图案化方法

对呼吸图技术制备二维有序多孔结构的研究进展进行了综合评述, 并重点介绍了本课题组发展的静态呼吸图技术. 利用静态呼吸图法, 可制备高度有序的聚合物、聚合物/无机物微孔膜. 这些有序的结构可以直接应用于光掩膜. 进一步, 多孔聚合物膜可以被紫外光交联和改性. 表面改性的多孔聚合物膜可以用于细胞支架. 而交联的聚合物/无机物前驱体微孔膜可以用来制备无机纳米材料阵列. 结果表明, 静态呼吸图技术是一种简单、高效的对聚合物、聚合物/无机物薄膜进行图案化的通用方法,并展示了图案化薄膜广阔的功能化前景.     

蜂窝状有序膜功能化研究进展*

水滴模板法是近年来引人瞩目的一种制备有序微结构材料的方法,所制备的蜂窝状有序膜在微容器和微反应器、图案化模板、细胞培养支架、光学材料、超疏水表面、分离膜等领域具有十分重要的应用前景。本文对蜂窝状有序膜功能化研究的最新进展进行了系统总结,详细介绍和分析了原位多层次自组装、表面接枝、生物活性分子固定、交联、模板法成膜以及表面填充等蜂窝状有序膜的功能化方法。     

微结构化弹性体介电层的制备方法与应用

微结构化弹性体薄膜是指在表面或内部具有多孔或者特殊造型阵列的微纳米尺寸结构的弹性体薄膜,这类薄膜作为功能化介电层在柔性电子器件的制备领域获得了广泛的应用。本文从微结构弹性体介电层的制备和应用两个方面来介绍微结构弹性体介电层的研究进展,首先介绍了可用以制备介电层的弹性体的种类,然后综述了多孔和非多孔阵列两大类微结构弹性体介电层的制备方法(氯化钠模板法、糖模板法、碳酸氢盐类模板法、微球模板法和硅模板法等);并介绍了微结构弹性体介电层在应力应变传感器和纳米发电机上的应用。     

聚合物材料表面微结构调控新策略

聚合物材料表面微结构对其功能化的实现具有至关重要的作用。在过去几十年的时间里,通过电纺、光刻、等离子处理等经典方法制备了各种各样的结构功能表面,实现在光、电、生物、化学等领域的广泛应用。然而为满足技术发展需求,实现表面微结构调控新策略的开发势不可挡。本文主要从分子扩散、材料内应力、外力的施加/释放,以及多种机制协同作用四个角度出发对聚合物表面结构调控的新策略进行介绍,并对今后聚合物表面结构调控的发展方向进行简要论述。     

利用去湿现象制备图案化的离子刻蚀聚合物保护层

微米和纳米尺度的图案化表面的制备在微电子、光学、生物、化学和材料科学等领域具有重要的科学意义和应用价值 [1～ 3 ] .由于需要复杂昂贵的设备和苛刻的工作环境 ,光刻技术难以广泛应用于微电子以外的领域 ,因此 ,发展简单、便宜、适用于普通实验室 (尤其是化学实验室 )的表面图案化技术已成为一个涉及众多学科领域的课题 .在近年来不断涌现出来的物理、化学和生物的表面图案化技术 [4～ 6]中 ,最具代表性的是由 Whitesides等 [7]发明的以表面具有微观图案的聚二甲基硅氧烷 (PDMS)弹性体作为模具或印章的软光刻技术 .结合溶胶 -凝胶、…     

利用软模板和紫外光固化技术制备超疏水表面

研究了一种制备超疏水表面的新方法.该方法以复制了荷叶表面结构的聚二甲基硅氧烷(PDMS)弹性体为软模板.利用可紫外光交联预聚物在模板压印条件下固化成型,得到了具有微乳突结构的仿荷叶表面.制备的仿荷叶表面表现出了超疏水性能.通过对紫外光固化体系中的单体含量、交联剂含量、引发剂含量、以及紫外曝光时间等因素的研究,得到了使仿荷叶表面的疏水性优化的条件.     

钙钛矿型纳米晶薄膜的制备及其光催化性能的研究

采用溶胶-凝胶法结合旋转涂膜工艺在玻璃基底上制备出了多层纳米晶薄膜LaMO3(M=Fe,Mn,Co,Cr);采用DSC/TG技术分析了前驱体凝胶的热分解历程;利用场发射扫描电镜观察了薄膜的表面形貌及膜层厚度.通过XRD进行了物相分析,并计算了其晶粒尺寸;实验结果表明,制备出的LaM03多层薄膜具有钙钛矿晶型结构,薄膜形态比较均匀.将该类薄膜作为光催化剂,对多种水溶性染料进行了光催化降解实验.研究结果表明,纳米晶薄膜LaM03的光催化活性主要和M原子的电负性及M离子的d电子结构有关.当M为Co时,薄膜的光催化效果最好.     

二氧化碳和丙烯直接合成甲基丙烯酸的NiPMo/TiO2催化剂的研究

用溶胶-凝胶法以磷钼酸(MPA)的镍盐溶液水解钛酸四丁酯制备了NiPMo/TiO2催化剂.使用ICP、 XRD、 TG-DTA、 IR、 TPD-MS和微反应技术研究了催化剂的化学组成、热稳定性、化学吸附性质和催化反应性能.杂多钼酸盐与TiO2通过O2-在TiO2表面发生了键合.在623 K下,杂多阴离子仍保持原有的Keggin结构.CO2在Lewis酸位Ni(Ⅱ)和Lewis碱位Ni-O-Mo的桥氧协同作用下生成CO2卧式吸附态Ni(Ⅱ)←O-(CO)←(O--Ni).丙烯有多种吸附态在催化剂上吸附.在563 K、 1 MPa和空速1500 h-1的反应条件下,丙烯的摩尔转化率为3.2%,产物MAA选择性为95%.     

α-Amino acid derived enaminones and their application in the synthesis of N-protected methyl 5-substituted-4-hydroxypyrrole-3-carboxylates and other heterocycles

A new and simple synthesis of novel N-protected methyl 5-substituted-4-hydroxypyrrole-3-carboxylates, which exist in equilibrium with their 4-oxo tautomers, has been developed in two steps starting from N-protected α-amino acids. The key intermediates are enaminones, which can also be isolated, characterized, and used for the construction of other functionalized heterocycles, before they spontaneously decompose to pyrrole products. 4-Hydroxypyrroles are prone to partial aerial oxidation but can be efficiently alkylated or reduced to stable polysubstituted pyrrolidine derivatives.     

Specific intramolecular aromatic CH insertion of diazosulfonamides

The chemoselectivity in the intramolecular CH insertion of various diazosulfonamides has been experimentally studied. The results reveal that the aliphatic 1,4-, 1,5-, or 1,6-C(sp³)?H insertions of diazosulfonamides are not accessible, while the aromatic 1,5-C(sp²)?H insertion can be realized specifically by adjusting the diazo-adjacent group. In addition, the general chemoselectivities in the intramolecular CH insertions of diazosulfonyl compounds are summarized. Generally, diazosulfones undergo both aromatic 1,5-C(sp²)?H and aliphatic 1,5- and 1,6-C(sp³)?H insertions, while diazosulfonates undergo aliphatic 1,5- and 1,6-C(sp³)?H insertions. However, diazosulfonamides only undergo aromatic 1,5-C(sp²)?H insertion.     

CoFe2O4自形成磁性液体场致结构化对磁化的影响

The Langevin paramagnetic theory can’t describe the relation between magnetization of ferrofluids and applied magnetic field. The structuralization of ferrofluids, which is considered the main influence factor of the magnetization, is regarded. The part of magnetization works is deposited when the structure is forming. This action influences the magnetization of ferrofluids directly or indirectly. On the base of the “compressing” model, the Langevin function that usually describes the magnetization of ferrofluid is modified, and a well-fitted curve is obtained. An equation of the relation between the equivalent volume fraction after being “compressed” and the intensity of magnetic field is discovered, which approximately describes the process of magnetization. The relation between the approximate initial susceptibility and the volume fraction can be obtained from modified formula.     

Highly regioselective Buchwald–Hartwig amination at C-2 of 2,4-dichloropyridine enabling a novel approach to 2,4-bisanilinopyridine (BAPyd) libraries

The highly regioselective Buchwald–Hartwig amination at C-2 of the cheap and readily accessible reagent, 2,4-dichloropyridine with a range of anilines and heterocyclic amines is described. This new methodology is robust and provides a facile access to 4-chloro-N-phenylpyridin-2-amines on 0.25 mol scale. These intermediates undergo a further Buchwald–Hartwig amination at higher temperature to enable rapid exploration of the chemical space at C-4 and to provide a library of 2,4-bisaminopyridines.     

N-Heterocyclic carbene-palladacyclic complexes: synthesis,characterization and their applications in the C-N coupling and α-arylation of ketones using aryl chlorides

N-Heterocyclic carbene-palladacyclic complexes 3 were successfully achieved in a one-pot procedure under mild conditions. The structure of 3a was unambiguously confirmed by X-ray single crystal diffraction and it was an active catalyst in the Buchwald-Hartwig amination and α-arylation of ketones even at very low catalyst loadings (0.01?mol%).     

Iodine-mediated oxidative Pictet-Spengler reaction using terminal alkyne as the 2-oxoaldehyde surrogate for the synthesis of 1-aroyl-β-carbolines and fused-nitrogen heterocycles

An efficient iodine-mediated oxidative Pictet-Spengler reaction in dimethyl sulphoxide (DMSO) using terminal alkynes as the 2-oxoaldehyde surrogate for the synthesis of aryl (9H-pyrido[3,4-b]indol-1-yl)methanones is described. The scope of the protocol includes the total synthesis of Fascaplysin, Eudistomins Y₁ and Y₂. The methodology is extended for preparing pyrrolo[1,2-a]-quinoxaline and indolo[1,5-a]quinoxaline derivatives. The utility of 1-aroyl-β-carbolines was demonstrated by performing palladium-catalyzed β-carboline directed ortho-C(sp2)-H functionalization of the phenyl ring with thiomethyl (SMe) group using DMSO as source and for accessing 4-aryl-canthin-6-ones.     

Facile synthesis of bicyclic 1-arylpyrazol-5-ones

In this Letter, we described a facile method for constructing fused bicyclic 1-arylpyrazol-5-one ring system. We employed various methylene-containing carboxylic acids as the substrates and proved that the pyrazolone ring closure requires activated methylene group in intermediate II. Accordingly, a series of structurally diversified, fused bicyclic 1-arylpyrazol-5-ones was prepared in moderate to high yields using the requisite substrates.     

Sulfur-directed metal-free and regiospecific methyl C(sp3)–H imidation of thioanisoles

Regiospecific and direct imidation of the methyl C(sp³)–H bond of thioanisoles is realized under mild and metal-free conditions with N-fluorobis(benzenesulfonyl)imide as an oxidant and nitrogen source. Proposed mechanism suggests that thionium ion intermediates and a Pummerer-type reaction are involved. The imidation has advantages such as high step-economy, excellent functionality tolerance, and regiospecificity, giving structurally diverse imidation products.