Surface functionalization, of silicon

Optimal Surface Functionalization of Silicon Quantum Dots... 

Fig. 3.10 (a) Schematic representation of the absorption and emission processes, (b) Calculated absorption and emission energies of SiQDs as a function of the electronegativity of the surface functionalization elements [26]. Reprinted with permission from (Li QS, Zhang RQ, Lee ST, Niehaus TA, Frauenheim T (2008) Optimal surface functionalization of silicon quantum dots, J Chem Phys 128 244714). Copyright (2008), American Institute of Physics... 

Li QS, Zhang RQ, Lee ST, Niehaus TA, Erauenheim T (2008) Optimal surface functionalization of silicon quantum dots. 1 Chem Phys 128 244714... 

Surface Functionalization of Silicon Clean the silicon or glass pieces in 96% ethanol for 2 min. Transfer the pieces to the previously prepared 2% APTES solution and incubate at room temperature for 30 min. As a control, prepare a sample without the APTES. Wash the pieces twice for 2 min each with 96% ethanol. Transfer the pieces to 2.5% glutaraldehyde solution and incubate at room temperature for Ih. As a control, prepare a sample without glutaraldehyde. Wash the pieces twice for 2 min each with Milli-Q water and blow-dry afterward. 

In Section V, a general discussion of how silicon surfaces can be used to obtain monolayers is presented. The functionalization of silicon surfaces using radical chemistry is an area of intense and active investigation because of the potential for a myriad of practical applications.In order to help those readers who are not familiar with silyl radical chemistry, we discuss some general aspects of silyl radicals in Section II, together with some recent findings. 

The radical-based functionalization of silicon surfaces is a growing area because of the potential practical applications. Although further knowledge is needed, the scope, limitations, and mechanism of these reachons are sufficiently well understood that they can be used predictably and reliably in the modification of hydrogen-terminated silicon surfaces. The radical chemistry of (TMSlsSiH has frequently served as a model in reactions of both hydrogen-terminated porous and flat silicon surfaces. We trust that the survey presented here will serve as a platform to expand silicon radical chemistry with new and exciting discoveries. 

In dentistry, silicones are primarily used as dental-impression materials where chemical- and bioinertness are critical, and, thus, thoroughly evaluated.546 The development of a method for the detection of antibodies to silicones has been reviewed,547 as the search for novel silicone biomaterials continues. Thus, aromatic polyamide-silicone resins have been reviewed as a new class of biomaterials.548 In a short review, the comparison of silicones with their major competitor in biomaterials, polyurethanes, has been conducted.549 But silicones are also used in the modification of polyurethanes and other polymers via co-polymerization, formation of IPNs, blending, or functionalization by grafting, affecting both bulk and surface characteristics of the materials, as discussed in the recent reviews.550-552 A number of papers deal specifically with surface modification of silicones for medical applications, as described in a recent reference.555 The role of silicones in biodegradable polyurethane co-polymers,554 and in other hydrolytically degradable co-polymers,555 was recently studied. 

Silicon wafers can act as substrates in the fabrication of DNA arrays. Chemical functionalization of silicon surfaces is compUcated by the fact that silicon spontaneously oxidizes in air to produce an amorphous sihca layer. 

Wacaser, B. A., Maughan, M. J., Mowat, I. A., Niederhauser, T. L., Linford, M. R. and Davis, R. C. Chemomechanical surface patterning and functionalization of silicon surfaces using an atomic force microscope. Applied Physics Letters 82, 808 (2003). 

Methods for the direct organic functionalization of silicon using wet chemical methods usually begin with H-terminated silicon surfaces. This is because the H-terminated surface is reasonably stable and thus can be handled in various solvents, facilitating the attachment of a variety of molecules via solution phase chemical reactions. While both H-terminated Si(lll) and Si(100) surfaces have been used as starting points for organic... 

One of the key problems in the functionalization of silicon via solution methods is the possibility of unwanted side reactions, most notably oxidation. Silicon surfaces are known to be highly susceptible to oxidation. XPS spectra of even carefully prepared surfaces invariably show a significant Ols... 

Chemically modified silica fillers with grafted methyl groups or methyl and silicon hydride groups, influenced the micro- and macrostructures of various copolymers. Changes in cross-linking, orderliness, crystallinity, microtacticity and conformation of macromolecules have been detected in the presence of fillers. Surface functionality of the silica filler determines the disposition of macromolecular chains at the interface. 

Figure 10 shows a three dimensional plot of the Si 2p spectrum as a function of silicon dioxide film thickness obtained by sequentially etching a 250 A thick oxide with HF/ethanol (34). Monochromatic Al k-a x-rays were used to excite the spectra in a standard XPS system. Notice that the Si 2p component due to the substrate is observed at about 100 A from the interface because the escape depth is about 38 A for 1386 eV electrons (32). Suboxides at the interface begin to appear as a prominent shift in the 2p components at about 20 A and are present up to the Si surface. Grunthaner, et al. (34) showed that the interfacial region consists of approximately 1 monolayer of Si,0, SiO and Si,0, in a 2 3 2... 

In conclusion, the recombinant SslA is able to self-assemble in vitro onto Si surfaces into large monolayers. Consequently, it may be used for a biological functionalization of silicon surfaces as a geometrically and physicochemically precisely defined immobilization matrix. 

The possibility of surface functionalization of the hydroxylated surface of silicon based materials with phosphazene substrates has been explored by a combination of experimental XPS analysis and theoretical ab initio calculations it has been shown that, in the interaction of [N3P3CI6] with the Si(100)-OFI surface, water plays a crucial role and a solvent such as THF is essential. " Also, the specific surface modifications of silicon-based materials such as silica gel beads and crystalline Si(lOO) wafers, have been achieved by reacting the residual with the pendant NHCFl2CH2CH2Si(OMe)3 groups of cyclotriphosphazenes carrying an equimole-cular proportion -OCeH4-/ -CN substituents used as markers through its IR band at 2230 cm. ... 

Reaction Functionalization of silicon surface via silianization reaction to covalently immobilize a DNA sensing probe. 

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