Organoclay materials

Organoclay materials with higher-order organization can also be prepared by template-directed methods involving self-assembled supramolecular structures. In this approach, preformed organic architectures in the form of tubes, fibers, hollow shells, gyroids, helicoids, and so on are transferred into hybrid materials exhibiting structural hierarchy, complex form and ordered mesoporosity [47-55]. For example,... 

Jaber, M., M-Brendle, J., Michelin, L. and Delmotte, L. (2005) Heavy metal retention by organoclays synthesis, applications, and retention mechanism. Chemistry of Materials, 17, 5275-5281. 

Muthusamy, E., Walsh, D. and Mann, S. (2002) Morphosynthesis of organoclay microspheres with spongelike or hollow interiors. Advanced Materials, 14, 969—972. 

M. and Mann, S. (2003) Higher-order synthesis of organoclay pipes using self-assembled lipid templates. Advanced Materials, 15, 1816-1819. 

Patil, A.J., Muthusamy, E. and Mann, S. (2005) Fabrication of functional protein-organoclay lamellar nanocomposites by biomolecule-induced assembly of exfoliated aminopropyl-functionalized magnesium phyllosilicates. Journal of Materials Chemistry, 15, 3838-3843. 

Brixie JM, Boyd SA (1994) Treatment of contaminated soils with organoclays to reduce leachable pentachlorophenol. J Environ Qual 23 1283-1290 Brown MJ, Burris DR (1996) Enhanced organic contaminant sorption on soil treated with cationic surfactants. Ground Water 34 734-744 Burris DR, Antworth CP (1992) In situ modification of an aquifer material by a cationic surfactant to enhance retardation of organic contaminants. J Contam Hydrol 10 325-337... 

G. Beyer, Filler blend of carbon nanotubes and organoclays with improved char as new flame retardant system for polymers and cable applications, Fire and Materials, vol. 29, pp. 61-69, 2005. 

One can certainly expect more work in the area of organoclay-doped liquid crystals in the near future. The hope is that these studies will not be limited to polar 5CB as a host material only, which is not necessarily an ideal host, but explore other nematic systems and other liquid crystal phases. 

For the materials and concentration ranges we have studied, comparative batch tests have supported the use of linear isotherms (e.g., Khandelwal et al., 1998 Khandelwal and Rabideau, 2000), although the assumption of a linear isotherm may not be appropriate for all systems. In particular, Mott and Weber (1992) and Gullick (1998) have utilized nonlinear isotherms to describe the behavior of various sorbing additives, including flyash and organoclays. However, it is important to note that multi-parameter nonlinear isotherms are not easily calibrated from column data, particularly if a sorption rate constant must also be estimated. 

In this work, tests were also conducted for other polymers with different type or loading of nanoparticles. These materials are an ethylene-vinyl acetate (EVA) nanocomposite with 5 wt % organoclay by Kabelwerk EUPEN AG/Belgium, and a PBT nanocomposite with 5 wt % Sepiolite. The samples size is the same as the one for PA6 (i.e., 100 x 100 x 6 mm). Similar to the PA6 tests, three external heat fluxes (40, 50, and 60kW/m2) were used with duplicated tests at each heat flux level. 

---