Colloid imprinting method

One of the advantages of the colloidal imprinting method is the ease of controlling the pore size as well as pore size distributions by choosing proper colloids [IS]. As shown in [16] the... 

Li Z., Jaroniec M., Lee Y. J. and Radovic L. R., Hi surface area graphitized carbon with uniform mesopores synthesised by colloidal imprinting method. Chem. Commun. (2002) pp. 1346-1347. 

Preparing carbons with hierarchical pore structure is done by impregnation of preformed macropo-rous structures, such as silica colloids, with the carbon precursor gels, followed by precursor carbonization and macropore template dissolution. Although in hard-templated carbons, two particle sizes of the hard template are simultaneously required for the colloidal imprinting method the soft-templating method makes this procedure much simpler and broadens the selection of templates for the larger mesopores and macropores. 

Jaroniec s group reported the synthesis of mesoporons carbons by using Lichrosper Si 100 silica spherical particles as tanplates and a synthetic meso-phase pitch or acrylonitrile as the carbon precursors [229]. Such carbons possess mesoporosity with negligible microporosity. Recently, a colloidal imprinting (Cl) method for prodncing mesoporous carbons was also described by Jaroniec and coworkers, as schematically illustrated in Fignre 2.30 [66-68]. The key to this... 

Synthetic polymer spheres with the ability for molecular recognition represent a promising alternative to affinity binding matrices using biological molecules. This chapter describes various methods for the preparation of molecularly imprinted polymer spheres in the colloidal state. The synthesis, characterization, and performance of colloidal dispersions of molecularly imprinted polymer spheres and their application are discussed. 

In this chapter we describe various methods for preparing molecularly imprinted polymers (MIP) in a colloidal state. The resulting materials consist of submicron scale particles dispersed in a liquid acting as fully functional synthetic affinity receptors. The synthesis, characterization, and performance of colloidal molecularly imprinted polymers are described and applications with this new class of affinity receptors is discussed. 

To use this method for the preparation of imprinted colloids, Whitcombe et al. applied it during the shell preparation. They synthesized a copolymer network shell consisting of poly(EGDMA-co-cholesteryl (4-vinyl)phenyl carbonate) using a variety of different seed particles to build the polymer core [26]. The seed particles used were 30-45 nm in diameter and the imprinted p(EGDMA-co-CVPC) shell resulted to a thickness of about 15 nm (Fig. 3). The specific BET surface area of the core-shell particles was typically 80 m2 g... 

Unfortunately, to date, this technique has received little attention from the molecular imprinting community and only one report of a dispersion polymerisation method had appeared until very recently [26]. This is probably better classified as a precipitation polymerisation, since random aggregates were produced rather than beads. No colloidal stabilisers were included in this procedure. The aggregates were made in situ in chromatography columns, which avoided the need to grind and sieve the polymer and pack the columns. Due to the rather polar nature of the solvent mixtures used (cyclohexanol, dodecanol, isopropanol), good imprints were only achieved for compounds which interact strongly with functional monomer... 

The author s own interest in this area includes new functional polymers for solid phase synthesis [11-13], polymers with molecularly imprinted substrate selectivity [14], polymer-supported transition metal catalysts [15], novel polymers of potential interest for electrocatalysis [16], targeting of colloidal drug carriers [17, 18], molecular composites [19], and biocompatible surfaces [20]. These studies have led to, among other things, a uniquely versatile method of polymer synthesis based on the chemistry of activated acrylates, i.e. polymer synthesis via activated esters. Various aspects of polymers and copolymers of activated (meth)acrylates have also been investigated in this and several other laboratories. 

Nanocapsules (hollow nanoparticles, nanospheres) are submicrometric colloidal objects composed of a liquid core surrounded by a thin silicone shell. The vesicle templating, solidification in emulsion and solidification of vesicles are the main methods for preparation of the silicone nanocapsules. The vesicle templating method is based on imprinting in the prepared materials the shape and size of the vesicles used as a template. Among the most popular templates are vesicles created from phospholipids (liposomes), double-tailed... 

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