介孔沸石合成方法的研究进展

系统地总结了介孔沸石的合成方法,包括对合成的沸石分子筛的后处理、硬模板法和软模板法;并就制备方法和产品结构的特点进行了评述。后处理法包括对沸石分子筛的脱铝处理、脱硅处理及热处理;硬模板主要包括碳纳米粒子、介孔碳黑、碳纳米管、碳纳米纤维、碳气凝胶、有序介孔碳、胶体复制碳、无机纳米粒子等;软模板主要包括高分子聚合物和有机硅烷模板剂。     

模板法制备纳米材料研究进展

模板法可以有效控制所合成纳米材料的形貌、结构和大小,因而成为目前制备纳米材料的一种重要手段。本文主要综述了软、硬模板法制备纳米材料的研究进展,重点介绍几种高分子聚合物为模板制备无机纳米材料的基本原理和主要特点,并在此基础上提出了模板法制备纳米材料需要解决的问题和应用前景。     

微乳液法制备纳米材料的研究进展

微乳液法制备纳米材料可以控制纳米粒子的大小和形状。本文综述了影响纳米粒子的主要因素和微乳液法制备纳米材料的最新研究进展。     

软模板法制备多级孔ZSM-5分子筛的研究进展

相比传统ZSM-5分子筛,多级孔ZSM-5分子筛具有空间位阻小、传质效率高、焦炭少等特点,近年来在分子筛领域应用广泛。多级孔分子筛通常可用后处理法和模板剂法制备,相比后处理法,模板剂法能更好地控制介孔的结构和孔道尺寸。概述了采用传统表面活性剂、两亲性的有机硅烷、双功能多季铵盐表面活性剂及高分子聚合物等软模板法合成多级孔ZSM-5分子筛的研究进展。分析不同软模板剂的特点和作用机理,阐述了合成后分子筛的结构特点及催化性能等。指出在今后的研究中,可以设计价格较低的新型功能化模板剂,优化合成过程,致力于在理解合成机理的前提下,寻找操作简单、绿色环保的合成路线,并将其推行到实际工业生产中。     

高分子微纳米球为模板制备磁性空心微纳米球的方法

本发明公开了一种微纳米材料技术领域的高分子微纳米球为模板制备磁性空心微纳米球的方法,即以表面带有负电荷的高分子微纳米球为模板,通过在微纳米球表面原位反应生成以磁性纳米粒子为壳,模板粒子为核的磁性复合微球,之后也可以在此微球表面包裹一层SiO2。进一步通过烧灼去除模板来获得空心磁性微纳米球。本发明易行、高效、容易规模化,制备的磁性空心微纳米球粒径可控性很好、且磁性壳层的厚度或磁响应强弱也可以根据要求进行调节。     

新型端胺基聚酰胺-胺树枝状大分子合成研究

研究了以丙烯酸甲酯、己二胺、对苯二酚为原料,采用发散法合成新型端胺基聚酰胺-胺树枝状大分子时,反应条件——温度、反应时间、催化剂对合成产物的结构的影响。利用该树枝状大分子的活性点分布均匀的特点,通过设计和控制树枝状大分子模板剂来控制纳米粒子材料的形状。     

聚合物孔隙率的研究

膜的应用在当今引起了广泛的关注。本文用L-S相转化法制备了PAN/PVC、PAN/PVA体系的非对称性膜和用PVP做成孔剂的PVC膜。以L-S相转化法成膜可以制得非对称型结构膜，这种膜结构具有极薄而致密的表层，有助于同时提高膜的选择性、渗透性及抗污染性。同时，探讨了孔隙率对膜结构和膜性能的影响。实验结果表明，用高分子来做膜材料，可以利用高分子的相容性的变化来控制膜的孔隙率，而调控制膜的势力学因素和动力学因素可以改变高分子的相容性，从而影响膜的结构和性能。实验结果证实了可以制备出PAN/PVC膜，PAN/PVA膜和用PVP做成孔剂的PVC膜。这里我们主要研究了这些膜的孔隙率。     

模板法制备纳米氧化铜的研究进展

在纳米材料的制备中模板法具有不可替代的地位,模板剂的加入使纳米材料的形貌、结构及尺寸得到有效控制,使得纳米材料拥有更为独特的性能,近几年对于纳米氧化铜的研究仍是热门话题,使氧化铜在各个领域得到了广泛应用。本文简述了模板法在纳米氧化铜制备中的应用情况,把常用的模板剂分为五种模板类型,并做了举例说明和分析总结,最后对模板法制备纳米氧化铜加以展望。     

导电高分子纳米材料的制备方法研究现状

导电高分子纳米材料不仅具有一定的导电性能,而且兼具纳米材料的特殊性能,因而在很多领域具有广泛的应用前景。本文将导电高分子纳米材料的制备方法分为模板法和无模板法两大类进行探讨,模板法又分为硬模板和软模板法,主要以聚苯胺的制备进行举例,对每种方法的优缺点进行了分析,并对导电高分子纳米材料的未来发展进行了展望。     

仿生合成多孔有序结构的SiO2粒子

以高分子微凝胶为模板,在中性水溶液中催化硅前体原位生成SiO2,形成的有机-无机杂化粒子具有模板分子的多级有序结构、多孔的表面性能及带电性.控制硅前体(TMOS)的用量,可以控制杂化粒子的比表面积和带电性,在载体材料、催化以及分离纯化等方面具有很好的应用前景.     

Facile synthesis of ultra-small hollow manganese silicate nanoparticles as pH/GSH-responsive T1-MRI contrast agents

Manganese silicate nanoparticles have recently attracted great attention due to the effectiveness of T₁-weighted magnetic resonance imaging (MRI) contrast agents (CAs) in the mildly acidic and high glutathione (GSH) conditions of the tumor microenvironment. Herein, ultra-small hollow manganese silicate (UHMS) nanoparticles were prepared via a facile, economical, and eco-friendly method based on a hydrothermal process using small silica nanoparticles as both the silicon source and templates. The nanoparticles showed remarkable biocompatibility and dispersion stability after modification with polyethylene glycol (PEG). Owing to their ultra-high longitudinal relaxation rate (r₁) at low pH values and high GSH levels, the UHMS@PEG nanoparticles have performed an excellent pH/GSH-responsive T₁-weighted MRI. Meanwhile, the nanoparticles showed insignificant cytotoxicity in vitro and in vivo. Therefore, the UHMS@PEG nanoparticles show promise as T₁-MRI CAs in the tumor microenvironment and may be used to assist in clinical cancer diagnosis.     

Polymeric Nanocapsule from Silica Nanoparticle@Cross-linked Polymer Nanoparticles via One-Pot Approach

A facile strategy was developed here to prepare cross-linked polymeric nanocapsules (CP nanocapsules) with silica nanoparticles as templates. The silica nanoparticle@cross-linked polymer nanoparticles were prepared by the encapsulation of the silica nanoparticles by the one-pot approach via surface-initiated atom transfer radical polymerization of hydroxyethyl acrylate in the presence of N,N′-methylenebisacrylamide as a cross-linker from the initiator-modified silica nanoparticles. After the silica nanoparticle templates were etched with hydrofluoric acid, the CP nanocapsules with particle size of about 100 nm were obtained. The strategy developed was confirmed with Fourier transform infrared, thermogravimetric analysis and transmission electron microscopy.     

Preparation of well-dispersed and anti-oxidized Ni nanoparticles using polyamioloamine dendrimers as templates and their catalytic activity in the hydrogenation of <Emphasis Type="Italic">p</Emphasis>-nitrophenol to <Emphasis Type="Italic">p</Emphasis>-aminophenol

p-Aminophenol was synthesized by catalytic hydrogenation of p-nitrophenol on Ni nanoparticles prepared by a chemical reduction method using polyamidoamine (PAMAM) dendrimers as templates. The as-prepared Ni nanoparticles were characterized by XRD, LRS, EDS, FTIR, FESEM, HRTEM and N₂ sorption analysis. Smaller-sized, better-dispersed and more active Ni nanoparticles can be successfully achieved using PAMAM dendrimers as templates. Analysis results show the as-prepared Ni nanoparticles are pure f.c.c. nickel. In hydrogenation reactions of p-nitrophenol, Ni nanoparticles show higher catalytic activity than that of Ni nanoparticles prepared in the absence of PAMAM dendrimers. The weight ratio of PAMAM/Ni²⁺ is proved to be an important parameter on the catalytic activity of Ni nanoparticles and the optimal ratio is 15%. The reason proposed for higher catalytic activity of Ni nanoparticles is a combination effect of smaller particle size, better dispersion and more active Ni nanoparticles.     

Soft vesicles in the synthesis of hard materials

Vesicles of surfactants in aqueous solution have received considerable attention because of their use as simple model systems for biological membranes and their applications in various fields including colloids, pharmaceuticals, and materials. Because of their architecture, vesicles could prove useful as "soft" templates for the synthesis of "hard materials". The vesicle phase, however, has been challenging and difficult to work with in the construction of hard materials. In the solution-phase synthesis of various inorganic or macromolecular materials, templating methods provide a powerful strategy to control the size, morphology, and composition of the resulting micro- and nanostructures. In comparison with hard templates, soft templates are generally constructed using amphiphilic molecules, especially surfactants and amphiphilic polymers. These types of compounds offer advantages including the wide variety of available templates, simple fabrication processes under mild conditions, and easy removal of the templates with less damage to the final structures. Researchers have used many ordered molecular aggregates such as vesicles, micelles, liquid crystals, emulsion droplets, and lipid nanotubes as templates or structure-directing agents to control the synthesis or assembly hard micro- and nanomaterials composed from inorganic compounds or polymers. In addition to their range of sizes and morphologies, vesicles present unique structures that can simultaneously supply different microenvironments for the growth and assembly of hard materials: the inner chamber of vesicles, the outer surface of the vesicles, and the space between bilayers. Two main approaches for applying vesicles in the field of hard materials have been explored: (i) in situ synthesis of micro- or nanomaterials within a specific microenvironment by vesicle templating and (ii) the assembly or incorporation of guest materials during the formation of vesicles. This Account provides an in-depth look at the research concerning the association of soft vesicles with hard materials by our laboratory and others. We summarize three main principles of soft vesicle usage in the synthesis of hard materials and detailed procedures for vesicle templating and the characterization of the synthetic mechanisms. By use of these guiding principles, a variety of inorganic materials have been prepared, such as quantum dots, noble metal nanoparticles, mesoporous structures, and hollow capsules. Polymerization within the vesicle bilayers enhances vesicle stability, and this strategy has been developed to synthesize hollow polymer materials. Since 2004, our group has pursued a completely different strategy in the synthesis of micro- and nanomaterials using vesicles as reactive templates. In this method, the vesicles act not only as templates but also as reactive precursors. Because of the location of metal ions on the bilayer membranes, such reactions are restricted to the interface of the vesicle membrane and solution. Finally, using the perspective of soft matter chemistry, we stress some basic criteria for vesicle templating.     

Surface-Enhanced Raman Scattering from Dye Molecules in Silicon Nanowire Structures Decorated by Gold Nanoparticles

Silicon nanowires (SiNWs) prepared by metal-assisted chemical etching of crystalline silicon wafers followed by deposition of plasmonic gold (Au) nanoparticles (NPs) were explored as templates for surface-enhanced Raman scattering (SERS) from probe molecules of Methylene blue and Rhodamine B. The filling factor by pores (porosity) of SiNW arrays was found to control the SERS efficiency, and the maximal enhancement was observed for the samples with porosity of 55%, which corresponded to dense arrays of SiNWs. The obtained results are discussed in terms of the electromagnetic enhancement of SERS related to the localized surface plasmon resonances in Au-NPs on SiNW’s surfaces accompanied with light scattering in the SiNW arrays. The observed SERS effect combined with the high stability of Au-NPs, scalability, and relatively simple preparation method are promising for the application of SiNW:Au-NP hybrid nanostructures as templates in molecular sensorics.     

成核剂在多元醇还原法超细磁粉制备中的应用

主要探讨多元醇还原法制备CoNi类超细磁粉过程中 ,使用Pt或Ag等贵金属作成核剂 ,有利于获得粒度均匀、尺寸可控制的颗粒材料。讨论了贵金属的种类、用量以及合金组分对颗粒材料结构和性能的影响。为制备纳米级、亚微米级的优质超细合金颗粒材料提供了可行方法     

Raman enhancement of rhodamine adsorbed on Ag nanoparticles self-assembled into nanowire-like arrays

ABSTRACT: This work reports on Raman scattering of rhodamine (R6G) molecules absorbed on either randomly distributed or grating-like arrays of approximately 8-nm Ag nanoparticles developed by inert gas aggregation. Optimal growth and surface-enhanced Raman scattering (SERS) parameters have been obtained for the randomly distributed nanoparticles, while effects related to the aging of the silver nanoparticles were studied. Grating-like arrays of nanoparticles have been fabricated using line arrays templates formed either by fracture-induced structuring or by standard lithographic techniques. Grating structures fabricated by both methods exhibit an enhancement of the SERS signal, in comparison to the corresponding signal from randomly distributed Ag nanoparticles, as well as a preferential enhancement in the areas of the sharp features, and a dependence on the polarization direction of the incident exciting laser beam, with respect to the orientation of the gratings structuring. The observed spectroscopic features are consistent with a line-arrangement of hot-spots due to the self- alignment of metallic nanoparticles, induced by the grating-like templates.     

Colloidal synthesis of Au nanoparticles using polyelectrolytes with 1,3,4-thiadiazole as reducing agents

Heterocyclic compounds are well known for their biological activity and coordination properties. Some heterocyclic compounds have been employed in the stabilization against coalescence of metallic nanoparticles in colloidal solutions, for example, tetrazole, triazole, and pyrazole. The aim of this work is to design new polyelectrolytes with heterocyclic pendant groups useful as reducing agents of Au³⁺ and as stabilizing agents for the synthesis of colloidal Au nanoparticles. Thus, polyelectrolytes with thiosemicarbazone and 1,3,4-thiadiazole pendant groups were used as reducing agents of Au³⁺ ions and stabilizing agents of Au nanoparticles. The voltammetry study of the polyelectrolytes showed that one with thiosemicarbazone pendant groups is the better reducing agent than polyelectrolytes with heterocyclic pendant groups. The polyelectrolytes can control the growth of the nanoparticles, obtaining structures with an average size of 9 nm. In this study, it was concluded that the nature of the heterocyclic group does not have an effect on the shape of nanoparticles and quasi-spherical nanoparticles were obtained with all polyelectrolytes. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 47790.     

Fabrication and characterization of silica/polypyrrole nanocomposites using silica sulfuric acid as templates

The sunflower‐like silica core‐polypyrrole (PPy) shell nanocomposites were prepared by using silica sulfuric acid as templates. The silica sulfuric acid was obtained by treating directly the silica nanoparticles with chlorosulfonic acid. The sulfonic groups (? SO₃H) on the surface of silica sulfuric acid not only offered the active sites for formation of polypyrrole particles but also acted as dopant agents in PPy. The nanostructures of sunflower‐like silica/PPy nanocomposites and hollow PPy capsules were investigated by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The molecular structure and content of PPy were determined by Fourier transform infrared (FTIR) and thermal gravimetric analysis (TGA), respectively. The highest conductivity of nanocomposites is 2.4 S/cm. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

正交实验法优化空心多孔SiO2纳米球对阿维菌素的吸附条件

以本实验室合成的空心多孔SiO2纳米球作为新型吸附介质,以阿维菌素为模型吸附药物,采用正交实验法对空心多孔SiO2纳米球的吸附参数进行了优化. 研究结果表明,利用无机-有机双模板法制备出的空心多孔SiO2纳米球具有很强的吸附能力,采用超临界流体技术能有效地把模型药物阿维菌素吸附到多孔空心结构中,吸附量可达61.5%. 在压力、温度、吸附时间、共溶剂用量4个影响吸附量的因素中,压力和共溶剂的影响具有显著性,吸附时间的影响较显著,温度的影响不显著. 最佳的吸附条件为：压力50 MPa,温度40℃,时间6 h,共溶剂(丙酮)添加量5 mL.