Clay surfaces, modified clays

Pantoustier, N., Alexandre, M., Degee, P, Calberg, C., Jerome, R., Henrist, C., et al. (2001). Poly(3-caprolactone) layered silicate nanocomposites effect of clay surface modifiers on the melt intercalation process. e-Polymer, 9, 1-9. 

Sondi, I.. Milat, O., and Pravdic, V., Electrokinetic potentials of clay surfaces modified by polymers, J. Colloid Interf. Sci., 189, 66, 1997. 

Ha Ha, S.-R., Rhee, K.-Y., Kim, H.-C., Kim, J.-T. Fracture performance of clay/epoxy nanocomposites with clay surface-modified using 3-aminopropyltriethoxysilane. CoUoids and Surfaces A - Physicochemical and Eng. Aspects 313-314 (2008) 112-115. 

In the last decade, considerable progress was observed in the field of PO/compatibil-izer (predominantly on the base of PO-g-MA)/organo-surface-modified clay nanocomposites. Polyethylene (PE), polypropylene (PP), and ethylene-propylene (EP) rubber are one of the most widely used POs as matrix polymers in the preparation of nanocomposites [3,4,6,30-52]. The PO silicate/silica (other clay minerals, metal oxides, carbon nanotubes, or other nanoparticles) nanocomposite and nanohybrid materials, prepared using intercalation/exfoliation of functionalized polymers in situ processing and reactive extrusion systems, have attracted the interest of many academic and industrial researchers because they frequently exhibit unexpected hybrid properties synergisti-cally derived from the two components [9,12,38-43]. One of most promising composite systems are nanocomposites based on organic polymers (thermoplastics and thermosets). 

Koo and co-workers [149] compared the benefits of incorporating three different types of nanoparticles on the mechanical properties of PA. The nanoparticles used were montmorillonite clay, surface modified silica and carbon nanofibre. 

Kaolin deposits are cored and analyzed before mining to determine quality. Mined clays are then either wet or dry processed by air floatation or water fractionation. Surface-modified clays can be made by treating standard, delaminated, and calcinated grades with surface modifiers. The treatment can be performed by either the supplier or the end user. These surface modifiers include silane, titanate, polyester, and metal hydroxide. The objective of these surface treatments is to increase filler loadings and/or improve physical properties such as melt viscosity, thermal stability, and modulus without loss of physical characteristics. Electrical applications represent the largest use of surface-modified kaolin in plastics. 

Triantafillidis, C.S. LeBaron, P.C. Pinnavaia, T.J. Thermoset epoxy-clay nanocomposites the dual role of alpha.omega-diamines as clay surface modifiers and pol3mer curing agents. J. Solid State Chem. 2002, 167, 354-362. 

Ha S R, Rhee K Y, Kim H C and Kim J T (2008) Fracture performance of clay/epoxy uanocomposites with clay surface-modified using 3-aminopropyltriethoxysilane, Coll Surf A Physicochem Eng Aspects 313-314 112-115. 

E - clay surface modified with 25-30 wt% octadecylamine (Nanoclay, USA),... 

P - clay surface modified with 35 - 45 wt% dimethyl dialkyl (C14-C18) amine... 

Polymer nanocomposites represent a rapidly expanding research area. Nanocomposites refer to a class of reinforced polymer with a low percentage of well dispersed nanopartieles. These materials often demonstrate notable improvement in properties such as mechanic characteristics, tensile strength, heat and chemical resistance. Nanoparticles can be classified based on how many dimensions are on the nanoscale. The first type is plate-like (e.g. nanoclays) that has a thickness in the nanometer range and lateral dimensions in the sub-micron or micron range. Two types of nanoclay, 20A (Southern Clay) and MHABS (a surface modified clay 20A), are used in our research. The second type has two dimensions in the nanometer range, such as carbon nanofibers (CNF) or carbon nanotubes. The third type has three dimensions in the range of nanometer, such as spherical silica particles. The latter type of nanoparticle is not used in our study. 

For example, the increment in maximum stress over the neat polymer is 100% and 53% in the case of the unmodified- and the modified-clay-fiUed samples, respectively. The extraordinary results obtained with the unmodified clays were explained with the help of thermodynamics and surface energetics. They explained it as follows. 

Vary the parameters within the above ranges. How does the soil type affect the transport of solutes Modify the model so that the soil characteristics vary with depth, e.g., a sandy soil near the surface becoming clay deeper below the... 

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