Liquid phase deposition

Ref. 27, which describes such reactions as liquid phase deposition, gives more details on this method. 

Very acidic (high valent) cations will readily hydrolyse in aqueous solution, often even at low pH. These cations tend to form the polymeric metal oxide chains mentioned previously. This hydrolysis can be controlled by addition of boric acid (see Sec. 3.2.4.4) and forms the basis of a technique referred to as liquid phase deposition. This method can be reasonably included in the more general term of chemical solution deposition, and is treated, although not comprehensively, in this book. Ref 5 deals more thoroughly with this technique and describes many cases of SiOi as well as some examples of several other oxides not covered in this chapter. 

I Liquid-liquid partition chromatography, where the sample components are partitioned between a moving liquid phase and a stationary liquid phase deposited on an inert solid. The two solvent phases must be immiscible. The stationary phase may he a large molecule chemically bonded lo the surface of a solid (bonded liquid phase) lo prevent loss by solubility in the moving phase. This method can also be subdivided into normal-phase systems, in which Ihe moving phase is less polar than the stationary phase, and reverse-phase systems, in which it is more polar. 

Fabrication methods that are generally used to make these junctions are diffusion, ion implantation, chemical vapor deposition (CVD), vacuum deposition, and liquid-phase deposition for homojunctions CVD, vacuum deposition, and liquid-phase deposition for heterojunctions and vacuum deposition for Schottky and MIS junctions. 

Abstract. Liquid phase deposition methods are a useful way to create mineral oxide films from aqueous solution under near-ambient conditions. These approaches have been applied to the creation of ceramic coatings on polymers and on polymer-matrix composites. Control has been achieved over the adherence and crystallinity of the solution-deposited thin films based on controlling the composition of both the deposition solution and the substrate surface. The challenge of depositing such films from water, while minimizing film cracking has also been addressed. Crack-free ceramic films of up to 200 nm thickness have been achieved on a variety of polymer substrates. 

K. Koumoto, S. Seo, T. Sugiyama, W. S. Seo, and W. J. Dressick, Micropatteming of titanium dioxide on self-assembled monolayers using a liquid-phase deposition process, Chem. Mater. 11, 2305-2309 (1999). 

A. Dutschke, C. Diegelmann, and P. Lobmann, Preparation of Ti02 thin films on polystyrene by liquid phase deposition, J. Mater. Chem. 13(5), 1058-1063 (2003). 

Fig. 16.17 SEM image of Ti02/CdS nanocables prepared by templated liquid-phase deposition [Reprinted from Hsu et al. (2005), Copyright (2005), with permission from Elsevier]...

Most film and particle formation techniques can be divided into gas-phase and liquid-phase deposition processes, which are briefly discussed in this section. Deposition of metal and metal oxides from metal enolate sources results from application of CVD, ALD, spin-coating, electrochemical and sol-gel methods, which are discussed in detail... 

Liquid-phase deposition (LPD) of Si02 is a relatively new process. ... 

Nanowires of 60-200 nm anatase Ti02 were fabricated using liquid phase deposition in a track etched membrane [47]. The acidic precursor solution used was (NH4)2Tip6 (0.2 M) and H3BO3 (0.1 M) and was adjusted to a pH of around 1.4 with 1 1 ammonia solution. 

On the other hand, liquid phase deposition (LPD) has been demonstrated as a flexible wet chemical method for preparing metal oxide nanostructured films on electrode surfaces. By the LPD process, electroactive titanium dioxide (Ti02) films were prepared on graphite, glassy carbon and ITO. The electrochemical properties of such LPD Ti02 films were dependent upon the film thickness controlled by the deposition time. The LPD technique was easily combined with other techniques, e.g., seed-mediated growth, which could provide metal/metal oxide composite nanomaterials. Moreover, hybrid nanostructured films were facilely obtained by doping dyes, surfactants and other... 

In this chapter, we would like to introduce two wet chemical methods, namely a seed-mediated growth approach and a liquid phase deposition process, which have been successfully utilized to modify electrode surfaces with gold nanoparticles or Ti02 nanostructured films. Because both methods are soft , the particle size or film thickness is... 

Liquid Phase Deposition of Ti02 on Electrode Surfaces... 

Preparation of Ti02 Film Electrodes with Liquid Phase Deposition Process... 

Liquid phase deposition (LPD) process is the formation of oxide thin films from an aqueous solution of a metal-fluoro complex which is slowly hydrolyzed by adding fluoride scavengers such as boric acid or aluminum metal [47], namely... 

In addition, adjustment of the pore size of ferrierite through SiCLt liquid-phase deposition can also enhance the selectivity of isomerization of 1-butene to isobutene, because when the pore size of the zeolite is reduced, the formation of octane intermediate is inhibited.[71] Under suitable conditions, the isobutene selectivity can be increased from 48.8% to 82.5%. 

Figures 2-4 show substantial, though various or individual test compounds drop of heat of adsorption values caused by the addition of very small amount (about 2% mass) of PEG 4000 when PEG 4000 amount on the carbosil surface is higher the relationship becomes more complex. Extremes occur on the plots of the investigated relationships q = f(%PEG) in a similar way as in the case of graphitized black covered with PEG 1500 [44,45]. The occurrence of maxima and minima on the discussed type of plots was explained by the authors of the referred papers by formation of successive monolayers of liquid phase on the surface of carbon adsorbent. From the above and the well known [26,30,35] fact that heats of adsorption are usually higher on carbosils than on the non-modified surface of silica gel one would expect that the first portions of PEG 4000 are adsorbed on the surface of carbosil carbon patches. The fact that pores can on the surface of non-modified silica are narrower than on a carbosil surface [27] seems to confirm such a conclusion indicating reduction of adsorption site number on the silica surface. Thus the sequence of liquid phase deposition would be the following first on the carbon patches and then on the uncovered silica surface.

Of course silica coatings, being dielectric, will not be useful direct participants in water photolysis-photoreduction. This fact is demonstrated by the data of Tada et al. (13), reproduced in Figure 3, in which silica coatings ca. 1 nm in thickness [deposited by the so-called liquid-phase deposition or LPD process (14)] inhibit the photoreduction of aqueous silver ions. Researchers of aqueous photoredox chemistry have, however,... 

Liquid phase deposited titania coating to enable in vitro apatite formation on Ti6A14V alloy. /. Mater. Sci. Mater. Med.,... 

V2O5 catalysts were prepared by the chemical liquid-phase deposition (CLD) method [10], which is essentially identical to the graft method [11]. 

Liquid-phase deposition, such as the sol-gel and liquid-state deposition methods... 

In the second step, a liquid phase deposition occurs as a controlled hydrolysis of (NH4)2TiF6 in the presence of H3BO3 under acidic conditions. 

Malvadkar N, Dressick WJ, Demirel MC. Liquid phase deposition of titania onto nano-structured poly-/7-xylylene thin films. J Mater Chem 2009 19(27) 4796. 

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