Organic materials, incorporation into inorganic matrices

By the sol-gel-process, inorganic glassy and hybrid polymeric materials are accessible at comparatively low temperatures [1], Therefore, organic molecules or dyes can easily be incorporated into the oxide matrix. This combination is especially attractive for the development of the following devices optical filters, solid-state lasers, optical switches, nonlinear optical laser hosts, optical data storage media, and photoconductive devices and films [2]. 

The encapsulation of enzymes in a sol gel matrix is an immobilization method in which the enzymes are incorporated into hybrid organic-inorganic hydrophobic materials (alkylsilanes) [13]. The sol-gel process can easily be recognized because it is the synthesis route in which at a certain time, there is the transition from the sol to the gel system. In contrast to the conventional methods, which require high temperatures for the fusion of vitreous silica, the sol-gel technique uses low temperatures for the hydrolysis and... 

As described earlier, most of the studies on photocontrolled transport phenomenon focused on azobenzene-doped organic platforms such as planar lipid membranes and spherical vesicles, which have an intrinsic disadvantage. Those lipid membranes and vesicles are delicate and unstable, thus limiting their practical applications. Incorporation of the azobenzene moieties into a robust inorganic matrix greatly enhances the system stability and facilitates the device fabrication. For example, azobenzene moieties precisely positioned onto the pore surfaces of mesoporous silica membranes enable novel photocontrolled transport in the resulting composite materials (Liu et al., 2004). 

In the large field of nanotechnology, polymer-based nanocomposites have become a prominent area of current research and development for biomedical applications.In principle, nanocomposites are an extreme case of composite materials in which interface interactions between the two phases, the matrix and the reinforcement, are maximized. In the literature, the term nanocomposite is used for polymers with sub-micrometre dispersions. In polymer-based nanocomposites, nanometre sized particles of inorganic or organic materials are homogeneously dispersed as separate particles in a polymer matrix. Researchers have tried a variety of processing techniques to obtain dense polymer nanocomposite films. The incorporation of nanostructures into polymers can generally be done in different ways as indicated below ... 

Numerous other examples of supported catalyst systems have since been described in the literature from Shi [29], Grubbs [30], Thieuleux and Coperet [31, 32], and Pleixats and Wong Chi Man [33, 34]. All of these examples describe some form of a silica-supported analog, either from grafting onto commercial silica, or through the preparation of a hybrid organic-inorganic material prepared by sol-gel chemistry, with the functionality incorporated into the silica matrix. 

Another approach to improve the separation characteristics of a membrane is the implementation of additives. MMMs consist of an inorganic or inorganic-organic hybrid material in the form of micro- or nanoparticles (discrete or dispersed phase) incorporated into a polymer matrix (continuous phase) (Figure 3). ... 

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