介孔氧化硅薄膜材料的研究进展

介孔氧化硅薄膜在膜分离、传感器件、异相催化、低介电常数微电子绝缘片的应用方面具有潜在应用价值。首先简要介绍了介孔薄膜的制备途径，然后重点综述了介孔氧化硅薄膜的研究进展。     

Mesoporous Silica‐Based Materials with Bactericidal Properties

Bacterial infections are the main cause of chronic infections and even mortality. In fact, due to extensive use of antibiotics and, then, emergence of antibiotic resistance, treatment of such infections by conventional antibiotics has become a major concern worldwide. One of the promising strategies to treat infection diseases is the use of nanomaterials. Among them, mesoporous silica materials (MSMs) have attracted burgeoning attention due to high surface area, tunable pore/particle size, and easy surface functionalization. This review discusses how one can exploit capacities of MSMs to design and fabricate multifunctional/controllable drug delivery systems (DDSs) to combat bacterial infections. At first, the emergency of bacterial and biofilm resistance toward conventional antimicrobials is described and then how nanoparticles exert their toxic effects upon pathogenic cells is discussed. Next, the main aspects of MSMs (e.g., physicochemical properties, multifunctionality, and biosafety) which one should consider in the design of MSM‐based DDSs against bacterial infections are introduced. Finally, a comprehensive analysis of all the papers published dealing with the use of MSMs for delivery of antibacterial chemicals (antimicrobial agents functionalized/adsorbed on mesoporous silica (MS), MS‐loaded with antimicrobial agents, gated MS‐loaded with antimicrobial agents, MS with metal‐based nanoparticles, and MS‐loaded with metal ions) is provided.     

增强微孔二氧化硅氢气分离膜疏水性的研究现状

综述了提高微孔二氧化硅膜疏水性的方法以及微孔二氧化硅膜材料在氢气分离方面的应用.孔表面羟基是导致微孔二氧化硅膜亲水的主要原因,因此在溶胶-凝胶反应阶段用疏水基团来修饰溶胶,可以在最终材料的孔表面引入疏水基团,降低羟基浓度,从而提高其疏水性.修饰后的二氧化硅膜孔结构没有显著的变化,可以应用于氢气分离等领域.     

Ultrasmall Particle Sizes of Walnut‐Like Mesoporous Silica Nanospheres with Unique Large Pores and Tunable Acidity for Hydrogenating Reaction

The large particle sizes, inert frameworks, and small pore sizes of mesoporous silica nanoparticles greatly restrict their application in the acidic catalysis. The research reports a simple and versatile approach to synthesize walnut‐like mesoporous silica nanospheres (WMSNs) with large tunable pores and small particle sizes by assembling with Beta seeds. The as‐synthesized Beta‐WMSNs composite materials possess ultrasmall particulate sizes (70 nm), large radial mesopores (≈30 nm), and excellent acidities (221.6 mmol g^?1). Ni₂P active phase is supported on the surface of Beta‐WMSNs composite materials, and it is found that the obtained composite spherical materials can reduce the Ni₂P particle sizes from 8.4 to 4.8 nm with the increasing amount of Beta seeds, which can provide high accessibilities of reactants to the active sites. Furthermore, the unique large pores and ultrasmall particle sizes of Beta‐WMSNs samples facilitate the reduction of the diffusion resistance of reactants due to the short transporting length, thus the corresponding Ni₂P/Beta‐WMSNs composite catalysts show the excellent hydrogenating activity compared to the pure Ni₂P/WMSNs catalyst.     

Multiscale Design of Graphyne‐Based Materials for High‐Performance Separation Membranes

By varying the number of acetylenic linkages connecting aromatic rings, a new family of atomically thin graph‐n‐yne materials can be designed and synthesized. Generating immense scientific interest due to its structural diversity and excellent physical properties, graph‐n‐yne has opened new avenues toward numerous promising engineering applications, especially for separation membranes with precise pore sizes. Having these tunable pore sizes in combination with their excellent mechanical strength to withstand high pressures, free‐standing graph‐n‐yne is theoretically posited to be an outstanding membrane material for separating or purifying mixtures of either gases or liquids, rivaling or even dramatically exceeding the capabilities of current, state‐of‐art separation membranes. Computational modeling and simulations play an integral role in the bottom‐up design and characterization of these graph‐n‐yne materials. Thus, here, the state of the art in modeling α‐, β‐, γ‐, δ‐, and 6,6,12‐graphyne nanosheets for synthesizing graph‐2‐yne materials and 3D architectures thereof is discussed. Different synthesis methods are described and a broad overview of computational characterizations of graph‐n‐yne's electrical, chemical, and thermal properties is provided. Furthermore, a series of in‐depth computational studies that delve into the specifics of graph‐n‐yne's mechanical strength and porosity, which confer superior performance for separation and desalination membranes, are reviewed.     

Core‐Cone Structured Monodispersed Mesoporous Silica Nanoparticles with Ultra‐large Cavity for Protein Delivery

A new type of monodispersed mesoporous silica nanoparticles with a core–cone structure (MSN‐CC) has been synthesized. The large cone‐shaped pores are formed by silica lamellae closely packed encircling a spherical core, showing a structure similar to the flower dahlia. MSN‐CC has a large pore size of 45 nm and a high pore volume of 2.59 cm³ g⁻¹. MSN‐CC demonstrates a high loading capacity of large proteins and successfully delivers active β‐galactosidase into cells, showing their potential as efficient nanocarriers for the cellular delivery of proteins with large molecular weights.     

Synthetic Two‐Dimensional Materials: A New Paradigm of Membranes for Ultimate Separation

Microporous membranes act as selective barriers and play an important role in industrial gas separation and water purification. The permeability of such membranes is inversely proportional to their thickness. Synthetic two‐dimensional materials (2DMs), with a thickness of one to a few atoms or monomer units are ideal candidates for developing separation membranes. Here, groundbreaking advances in the design, synthesis, processing, and application of 2DMs for gas and ion separations, as well as water desalination are presented. This report describes the syntheses, structures, and mechanical properties of 2DMs. The established methods for processing 2DMs into selective permeation membranes are also discussed and the separation mechanism and their performances addressed. Current challenges and emerging research directions, which need to be addressed for developing next‐generation separation membranes, are summarized.     

Nanoparticles of Mesoporous SO3H‐Functionalized Si‐MCM‐41 with Superior Proton Conductivity

Nanometer‐sized mesoporous silica particles of around 100‐nm diameter functionalized with a large amount of sulfonic acid groups are prepared using a simple and fast in situ co‐condensation procedure. A highly ordered hexagonal pore structure is established by applying a pre‐hydrolysis step in a high‐dilution synthesis approach, followed by adding the functionalization agent to the reaction mixture. The high‐dilution approach is advantageous for the in situ functionalization since no secondary reagents for an effective particle and framework formation are needed. Structural data are determined via electron microscopy, nitrogen adsorption, and X‐ray diffraction, proton conductivity values of the functionalized samples are measured via impedance spectroscopy. The obtained mesoporous SO₃H‐MCM‐41 nanoparticles demonstrate superior proton conductivity than their equally loaded micrometer‐sized counterparts, up to 5 × 10^?2 S cm^?1. The mesoporosity of the particles turns out to be very important for effective proton transport since non‐porous silica nanoparticles exhibit worse efficient proton transport, and the obtained particle size dependence might open up a new route in rational design of highly proton conductive materials.     

MRI‐Visualized,Dual‐Targeting,Combined Tumor Therapy Using Magnetic Graphene‐Based Mesoporous Silica

Targeting peptide‐modified magnetic graphene‐based mesoporous silica (MGMSPI) are synthesized, characterized, and developed as a multifunctional theranostic platform. This system exhibits many merits, such as biocompatibility, high near‐infrared photothermal heating, facile magnetic separation, large T2 relaxation rates (r2), and a high doxorubicin (DOX) loading capacity. In vitro and in vivo results demonstrate that DOX‐loaded MGMSPI (MGMSPID) can integrate magnetic resonance imaging, dual‐targeting recognition (magnetic targeting and receptor‐mediated active targeting), and chemo‐photothermal therapy into a single system for a visualized‐synergistic therapy of glioma. In addition, it is observed that the MGMSPID system has heat‐stimulated, pH‐responsive, sustained release properties. All of these characteristics would provide a robust multifunctional theranostic platform for visualized glioma therapy.