Synthesis of Organic−Inorganic Hybrids via the Non-hydrolytic Sol−Gel Process

Abstract

In its most common form, the non-hydrolytic sol-gel (NHSG) process involves the reaction of a "metal" halide with an oxygen donor, leading to the formation of an inorganic oxide. The use of NHSG chemistry for the synthesis of organic-inorganic hybrids is in its infancy compared to progress on hybrid synthesis using hydrolytic sol-gel chemistry. To date, most work has been carried out on the synthesis of organically modified inorganic oxides such as ormosils, with very limited effort on oxide-polymer hybrids and no reported activity on incorporation of small organic molecules into oxide networks. In this paper, reports of the use of the NHSG route to synthesize hybrids are reviewed. The key features of the reaction chemistry are noted, along with a discussion of the scope and limitations of NHSG chemistry in comparison with the hydrolytic route. Promising areas for future study are proposed, together with potential applications of these hybrids.

Soft solution fluorine-free synthesis of anatase nanoparticles with tailored morphology

“…The use of oxygen donor groups other than water may allow a better control of the reaction rate, leading to slow particle growth. The problem is that under these conditions the reaction rate is drastically reduced, the process becomes excessively slow and the possibility of tailoring the morphology of the synthesized particles is hindered by kinetic considerations [23][24][25][26][27]. In this sense a promising alternative which has been recently considered combines both hydrolytic and non-hydrolytic reactions: by adding a certain amount of water into a nonaqueous media, the size and morphology of the Ti0 2 precipitated particles can be finely tuned [28].…”

Preparation and characterization of EPDM/silica composites prepared through non-hydrolytic sol-gel method in the absence and presence of a coupling agent

“…Moreover, the NHSG route features different reactions and reaction conditions, which significantly affect the texture, homogeneity and surface chemistry of the resulting oxide [4][5][6]. In the past 20 years, several non-hydrolytic synthesis methods of oxides and mixed oxides have been described, involving the reaction of precursors (alkoxides, chlorides, acetylacetonates) with oxygen donors (ethers, alcohols, ketones) [4][5][6][7][8][9][10]. The main non-hydrolytic routes involve the reaction of a metal chloride with either a metal alkoxide or organic ether, acting as oxygen donors [7][8][9] as described in Figure 1.…”

Condensation‐ and Crystallinity‐Controlled Synthesis of Titanium Oxide Films with Assessed Mesopores

“…Non-hydrolytic routes have often facilitated the fabrication of mixed metal oxides [1] and inorganic-organic hybrid materials. [2] Likewise, self-adjusted reactions between appropriate inorganic acidity and alkalinity pairs are a powerful method of constructing not only single and/or mixed metal oxides but also metal phosphates. [3] Although these studies have only focused on the initial formation of inorganic networks, subsequent condensation has not been discussed as adequately.…”