Functional Group Distributions on Mesoporous Silica

Abstract

Functional group distributions on mesoporous silica Brühwiler, D (2011 Functional group distributions on mesoporous silica Abstract Most applications of mesoporous silica require some degree of functionalization. The surface of porous materials can be divided into external and internal (pore) surfaces, and in many cases, a selective functionalization of these surface subsections is desired. This short review outlines our recent work in this field and focuses on the postsynthetic functionalization of mesoporous silica with aminopropylalkoxysilanes and on the analysis of the respective functional group distributions by confocal laser scanning microscopy. Methods to obtain an amino-functionalized external surface and functional group gradients on the pore surface are reported. Arrays of silica nanochannels (ASNCs) serve as a model system for mesoporous silica. 1 Functional Group Distributions on Mesoporous SilicaNando Gartmann and Dominik Brühwiler* AbstractMost applications of mesoporous silica require some degree of functionalization. The surface of porous materials can be divided into external and internal (pore) surfaces, and in many cases, a selective functionalization of these surface subsections is desired. This short review outlines our recent work in this field and focuses on the postsynthetic functionalization of mesoporous silica with aminopropylalkoxysilanes and on the analysis of the respective functional group distributions by confocal laser scanning microscopy. Methods to obtain an amino-functionalized external surface and functional group gradients on the pore surface are reported. Arrays of silica nanochannels (ASNCs) serve as a model system for mesoporous silica.

Spatial Distribution of Silica-Bound Catalytic Organic Functional Groups Can Now Be Revealed by Conventional and DNP-Enhanced Solid-State NMR Methods

“…Later studies by Gartmann and Brühwiler et al used confocal laser scanning microscopy (CLSM) to image the distributions of organic functionalities grafted onto porous silica host materials after coupling with appropriate fluorescent labels. [58][59] They showed that the loading and distribution of functional groups depended on their size and the pore diameter, as well as solvent polarity. In small-pore materials, selective grafting of the external surface could be achieved using a large orgnanoalkoxysilane precursor, such as 3-aminopropyltris(methoxyethoxyethoxy)silane (APTMEES), and a non-polar solvent (see Figure 4, left).…”

“…38,62 The CLSM imaging also demonstrated that trace amounts of water in the organic solvents used during grafting can lead to clustering of organosilanes and nonuniform distribution of functional groups on surfaces (Figure 4, right). [59][60] and studied their locations by observing Si and W using the EFTEM. 65 The elemental mapping showed patterns of alternating Si-rich and W-rich domains, which indicated that the organometallic tungsten complexes are located inside the channels of the mesoporous silica materials.…”

Synthesis of phenylalanine and leucine dipeptide functionalized silica-based nanoporous material as a safe UV filter for sunscreen

“…This study shows that the surface properties of functionalized mesoporous silica play an important role in UV protection. In other words, functional molecules used to modify mesoporous materials are crucial [20]. Compared with other biomolecules and organic molecules, peptides containing natural amino acids are widely used as surface modification units because of their inherent bioactivity, biodegradability, and biocompatibility [21].…”

An innovative method for anchoring glucose-sensing molecules on glassy micro-particles

“…However, the typical silanes used as APTES or APTMEES (3-aminopropyltriethoxysilane or 3-aminopropyltris methoxy ethoxy ethoxy silane, respectively) are quite expensive and usually affects the pore lead to decreasing mesoscopic order. 8 W Limbut et al 9 proposed in 2004 a method to immobilize urease on three different support based on SiO 2 for the determination of urea 9 and they showed the high efficiency of such interaction. Therefore, in this work we propose an innovation in the traditional method 10,11 for anchoring glucose-sensing molecules on an inorganic substrate using modified powdered silicate glasses as micrometric inner substrate, which is a very economical substrate and environmental friendly and anchoring a sensing molecules through an innovative and green chemical substance such is the urea.…”