Nanoporous Oxides and Organic-Inorganic Hybrid Materials for Catalysis and Biomedical Applications

在1-100 nm范围内具有良好孔隙的纳米材料（即纳米孔）在工业催化、环境修复以及作为药物/基因递送的生物相容性载体方面具有广阔的应用前景，因此受到人们的极大兴趣。介孔材料，特别是，被定义为无机框架（例如，二氧化硅，金属氧化物，碳），包含大通道或笼的周期性阵列，通常由2到15纳米组成。这种孔径范围提供了高表面积和高孔体积，使这些材料成为多功能催化剂或催化剂载体，以及生物活性物质的潜在宿主/转运体。该研究计划的主要目标是：1)开发新的高活性和低成本的非贵金属基催化剂家族，用于可持续化学生产和能源相关应用（例如，氢气生产，电催化）；2)设计生物相容性纳米多孔杂化材料，包含理想的官能团，并具有用于生物医学应用（例如，药物输送）的适当结构和粒径。除了合成和功能化，重点将放在催化剂和生物材料的性能评估和结构-性能关系的调整。介孔二氧化硅材料，如MCM-48、SBA-15，可以通过模板法结合定向结构胶束聚集体和无机溶胶-凝胶工艺制备，从而形成具有明确尺寸和形状的特定纳米孔。这些（纳米）结构为催化剂和药物传递系统的设计提供了一个极好的起点。模板化介孔二氧化硅被认为是无毒的，化学和热稳定。它们的表面硅烷醇基团允许固定多种功能。此外，定制孔隙结构（大小、形状）是可能的，以优化吸附和扩散参数。此外，可以控制材料颗粒的形态和尺寸以形成胶体（纳米）球体或薄膜。根据不同的应用目标，介孔二氧化硅将采用不同的功能化方法（例如，通过浸渍或包封插入金属阳离子和氧化物纳米颗粒；有机硅烷的空间选择性接枝；与功能性（生物）聚合物结合）。使用纳米铸造工艺，也将生产无二氧化硅的高表面积混合金属氧化物组合物（例如，Cu, Ni, Mn， Zn等），这种方法基于将金属盐浸渍到二氧化硅的孔隙中，作为硬模板（随后去除二氧化硅），或使用纳米结构层状氢氧化物前体。除了二氧化硅和氧化物外，介孔碳载体将通过二氧化硅纳米铸造和表面活性剂辅助合成来合成，然后改性以引入金属阳离子/氧化物位点。在催化方面，混合金属铜基材料（二氧化硅或碳负载，或纯混合金属氧化物）将在各种重要反应中进行研究，例如，在液相中转化H2储存介质以生产H2，甘油的选择性氢解。对于药物递送，我们将主要关注使用介孔有机二氧化硅纳米颗粒（尺寸在30至200纳米之间），在其外表面具有生物相容性聚合物（PEG，蛋白质）功能化，用于抗癌药物（静脉注射）和肽药物（口服）的递送和靶向释放。预计新的催化剂和治疗装置将导致加拿大涉及能源和生产、工业化学、保健和药品或环境补救的各种工业感兴趣的潜在市场技术。

Nanomaterials with well-defined pores in the range of 1-100 nm, i.e. nanopores, are of great interest because of prospects of application in industrial catalysis, environmental remediation, and as biocompatible carriers for drug/gene delivery. Mesoporous materials, in particular, are defined as inorganic frameworks (e.g., silica, metal oxides, carbon) containing periodic arrays of large channels or cages usually comprised between 2 and 15 nm. This range of pore size provides high surface area and high pore volume, making these materials versatile catalysts or catalyst supports and potential hosts/transporters for bioactive substances. The primary objectives of this research program are: 1) to develop new families of highly active and low-cost non-noble metal-based catalysts, to be used for sustainable chemical production and energy-related applications (e.g., H2 production, electrocatalysis); and 2) to design biocompatible nanoporous hybrid materials incorporating desirable functional groups and possessing adequate structure and particle size for biomedical applications (e.g., drug delivery). In addition to synthesis and functionalization, emphasis will be put on assessing the performance of the catalysts and biomaterials and the tuning of the structure-property relationships. Mesoporous silica materials, e.g., MCM-48, SBA-15, can easily be prepared through templating methods combining structure-directing micellar aggregates and inorganic sol-gel process, leading to specific formation of nanopores with well-defined size and shape. These (nano)structures represent an excellent starting point for the design of catalysts and drug delivery systems. Templated mesoporous silicas are considered non-toxic, and chemically and thermally stable. Their surface silanol groups allow fixation of a great diversity of functionalities. Moreover, tailoring of pore structure (size, shape) is possible in order to optimize adsorption and diffusion parameters. Also, morphology and dimension of the material particles can be controlled to form colloidal (nano)spheres or films. Depending on the application targeted, different functionalization approaches will be applied to mesoporous silica (e.g., insertion of metal cations and oxide nanoparticles via impregnation or encapsulation; spatially-selective grafting of organosilanes; conjugation with functional (bio)polymers). Silica-free high-surface-area mixed metal oxide compositions (e.g., Cu, Ni, Mn, Zn, etc.) will also be produced, using the nanocasting process, a method which is based on impregnation of metal salts into the pores of silica, serving as a hard template (followed by silica removal), or by using nanostructured layered hydroxide precursors. In addition to silica and oxides, mesoporous carbon supports will be synthesized both via silica nanocasting and by surfactant-assisted synthesis, and then modified to introduce metal cation/oxide sites. In catalysis, mixed metal CuO-based materials (silica- or carbon-supported, or as pure mixed metal oxides) will be studied in diverse important reactions, e.g., conversion of H2 storage media in liquid phase for H2 production, selective hydrogenolysis of glycerol. For drug delivery, we will mainly focus on using mesoporous organosilica nanoparticles (size between 30 and 200 nm), functionalized with biocompatible polymers (PEG, proteins) on their external surface, for delivery and targeted release of anti-cancer drugs (intravenous) and peptidic drugs (oral delivery). It is anticipated that the new catalysts and therapeutic devices will lead to potentially marketable technologies of interest to a wide variety of Canadian industries dealing with energy resources and production, industrial chemistry, healthcare and pharmaceuticals, or environmental remediation.