Composite colloid

Fabrication of composite colloidal spheres involves two steps submicron particles are fabricated from a material preferentially responsive to one class of chemicals followed by a step in which the submicron spheres are coated with a shell that is preferentially responsive to another class of chemicals. A colloidal crystal array is subsequently self-assembled into a 3D ordered film. 

Fig. 4.3 SEM images of the long range packing assembly of composite colloidal crystal array films assembled on different substrates (a) polycarbonate sheet, (b) Teflon sheet, and (c) Teflon film. The submicron particles were composed of 326 nm diameter polystyrene beads coated with a 20 nm thick Si02 shell. Scale bars in (a c) are 3.00, 3.00, and 2.72 pm, respectively...

The reversibility of interactions of the composite colloidal crystal film with different vapors was also evaluated. Figure 4.10 illustrates the dynamic response of the sensing film at several wavelengths (770, 835, and 870 nm) upon triplicate exposures to water vapor at four concentrations (0.02, 0.04, 0.07, and 0.1 PIPo). The response and recovery kinetics upon exposure to water vapor were fully reversible and rapid (under 5 s). A comparison of dynamic response of the sensing film at five different wavelengths upon exposures to water and toluene vapors at four concentrations is presented in Fig. 4.11. These data illustrate that the direction, magnitude, and kinetics of the responses to these vapors were quite different. 

We have shown a new concept for selective chemical sensing based on composite core/shell polymer/silica colloidal crystal films. The vapor response selectivity is provided via the multivariate spectral analysis of the fundamental diffraction peak from the colloidal crystal film. Of course, as with any other analytical device, care should be taken not to irreversibly poison this sensor. For example, a prolonged exposure to high concentrations of nonpolar vapors will likely to irreversibly destroy the composite colloidal crystal film. Nevertheless, sensor materials based on the colloidal crystal films promise to have an improved long-term stability over the sensor materials based on organic colorimetric reagents incorporated into polymer films due to the elimination of photobleaching effects. In the experiments... 

Seredych M, Bandosz TJ, Adsorption of ammonia on graphite oxide / aluminum polycation and graphite oxide/zirconium polyoxycations composites,/ Colloid Interface Sci. 2008, 324 25-35. 

Theocaris, P.S, (1984). On the evaluation of adhesion between phases in fiber composites. Colloid Polym. Sci. 262, 929-938. 

A. S. Muller, J. Gagnaire, Y. Queneau, M. Karaoglanian, J. P. Maitre, and A. Bouchu, Winsor behaviour of sucrose fatty acid esters Choice of the cosurfactant and effect of the surfactant composition, Colloids Surf., A 203 (2002) 55-66. 

Jones, C.D. Lyon, L.A. Photothermal patterning of microgel/gold nanoparticle composite colloidal crystals. J. Am. Chem. Soc. 2003, 125, 460-465. 

Wilson. B.A. and Crimp, M.J.. Prediction of composite colloidal suspension stability based upon the Hogg, Healy, and Fuerstenau inteipretation, Langmuir, 9, 2836, 1993. 

Joubran, R.F., Cornell, D.G. and Parris, N. (1993) Microemulsions of triglyceride and non-ionic surfactant-effect of temperature and aqueous phase composition. Colloid Surf. A, 80, 153— 157. 

Kato S, Sato K, Maeda D, Nomura M. A kinetic investigation of styrene emulsion polymerization with surface active polyelectrolytes as the emulsifier. II Effects of molecular weight and composition. Colloids Surf 1999 A153 127-131. 

A scheme of the fabrication procedure of composite colloidal gold-... 

Sun, Y., Wang, Y., and Zhitomirsky, I. (2013) Dispersing agents for electrophoretic deposition of Ti02 and Ti()2-carbon nanotube composites. Colloids Surf., As Physicochem. Eng. Aspects, 418, 131—138. 

Kozawa et al. proposed the use of ultra-fine carbon (UFC) and polyvinyl alcohol (PVA) composite colloid as additive to electrolyte [46]. They demonstrated that UFC—PVA colloid converts inactive PbS04 accumulated in the negative electrode into an active one and improves its solubility. These effects are due to the influence of UFC colloid to reduce the size of PbS04 crystallites produced on discharge. The UFC—PVA colloid solution comprises carbon black particles 0.15 mm in size and PVA in a ratio of 10 4 by weight. Addition of 5 vol% of UFC—PVA colloid to the cell electrolyte has been recommended, i.e., the amount of colloid solid carbon is about 0.25 g per 100 mL of electrolyte. The UFC—PVA colloid reduces the selfdischarge of negative plates and can act as an activator (de-passivator) of the sulfated lead electrode. 

Shamurina, M. V Poldugin, V. I. Pryamova, T. D. sotskii V. V Influence of particles modification on aggregates structure and conductivity of metal-fiUed film composites. Colloidal Journal, 1994,57(4), 580-584. 

Liposomes can be made entirely from naturally occurring substances, and are therefore biodegradable and nonimmunogenic. In some cases, the introduction of synthetic lipids is useful for specific characteristics such as stability and charge. The lipid composition, colloidal characteristics, and surface modifications also allow liposomes to have functional properties, such as stability, controlled release of the encapsulated molecules, specific targeting, and controlled pH and temperature sensitivity. 

Keywords Clays Emulsion polymerization Iron oxide Metals Organic/ inorganic composite colloids Particle morphology Pigments Quantum dots Silica Surface modification... 

In Other works, palladium [334-337] and rhodium [335-337] nanoparticles were formed onto the surface of PS-based polymer particles functionalized through the copolymerization of styrene with AA, MAA, and acrylonitrile. The resulting composite colloids were evaluated as catalysts for the hydrogenation of alkenes, the Rh-based composite showing activities close to commercially available products [336], Using the obtained Pd-functionalized polymer particles, nickel [338], nickel/cobalt [339], or cobalt [340] nanoparticles were anchored onto the surface through chemical metal deposition (electroless plating) [341],... 

Fig. 40 (a) Procedure for coating PS colloids with gold or silver, (b) TEM image of 580 nm PS colloids coated with gold, (c) SEM image of opals made of gold-coated PS composite colloids. Reproduced from [342] with permission of Wiley-VCH... 

W.L. Zhang, H.J. Choi, Fabrication and electrorheology of graphene oxide/ ionic N-substituted copolyaniline composite. Colloid Polym. Sci., 2013, 291, 1401. 

Many more consequences could be drawn for such composite colloidal systems, but our first question must be if systems of such a nature do really exist in the field of macromolecular and association colloids. We can answer, that such systems are really encountered (see p. 233-238, Ch. VIII 1 b - 1 e). So for instance composite systems of two liquid phases, whereby the colloid-rich liquid is ultra or sub-... 

An interesting point is further the position which solid particles absorbed from outside take up in these composite colloid objects. ... 

The position of the vacuoles does not represent an equilibrium position belonging to the composite colloid body consisting of two liquid coacervates. 

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