Modified montmorillonite

Paul, M., Alexandre, M., Degee, P., Henrist, C., Rulmont, A., and Dubois, P. 2002. New nanocomposite materials based on plasticized poly(L -lactide) and organo-modified montmorillonites thermal and morphological study. Polymer 44 443-450. 

Zhenyang, Y., Jingbo, Y., Shifeng, Y., Yongtao, X., Jia, M. and Xuesi, G. 2007. Biodegradable poly(L-lactide)/poly(3-caprolactone)-modified montmorillonite nanocomposites Preparation and characterization. Polymer 48 6439-6447. 

Rodriguez-Gonzalo E, Sanchez-Martin MJ, Sanchez-Camazano M (1993) Adsorption of parathion and paraoxon by modified montmorillonites. Toxicol Environ Chem 37 157-163... 

Highly selective exchange in illite and modified montmorillonites... 

Extremely high selectivities are frequently interpreted as "ion fixation", which suggests an irreversible phenomenon. This is the case for exchanges of Cs, Rb and K in illite clay minerals (95-96) as well as for Cu(NHj) exchange in fluorhectorite (66). However, reversibility was verified from the Hess law for adsorption of Cs, Rb and K on the high affinity sites in illite (91) and modified montmorillonites (101) as well as for the exchange of transition metal complexes (29, 75). 

The Li ions were introduced in two different ways either before or after Zr intercalation. The montmorillonite (Weston L-Eccagun) was first exchanged with NaCl (IN) and washed. Two montmorillonites with reduced charge were prepared following the Brindley and Ertem method (13). Part of the Na+ montmorillonite was first saturated with LiCl (IN) and washed. The Li+ clay thus obtained and Na+ clay suspension were stirred for 24 hours at 25°C and dried on glass plate. The films were then heated at 220°C for 24 h in order to allow Li diffusion in the clay structure. Two different Li concentrations (F=0.4 and F=0.6) were used. The Na Li+ modified montmorillonite were dispersed in water acetone solution (1/1). The ZrOCla, 8H2O solution was added to the Na+Li+ montmorillonite (0.02g.l l Zr/Clay=5.CEC). The suspension was stirred with NaOH solution (0.1 N) up to a OH/Zr ratio of 0.5. The final pH of the suspension was 1.85. After two hours of reaction at 40°C the Zr pillared clay was washed up to constant conductivity of the solution, freeze-dried and calcined at different temperatures up to 700°C (Eni-02 and EIII-03). 

Figures 1 and 2 report the IR spectra of the Na" " montmorillonite (A) and the Li" " modified montmorillonite [Na+Li+ 0.4 (B) Na+Li+ 0.6 (Q] before calcination (1), after calcination at 220°C (2) and orientation of the sample in the IR beam (3). These figures illustrate the OH stretchnig vibration (fig. 1) and the bending (fig. 2) vibrations of the non pillared samples.

Bowe CA, Krikorian N, Martin DF. Extraction of Heavy Metals Using Modified Montmorillonite KSF. Florida Scientist 2004 67 74-79. 

The incorporation of unmodified and organically modified montmorillonite nanoclays (namely 15A and 30B) in chlorinated polyethylene (CPE) by the solution intercalation method and their influence on mechanical properties of the nanocomposites have been studied by Kar et al. [137]. The o-MMT-embedded nanocomposites show enhanced tensile strength and Young s modulus in comparison to the nanocomposites containing the unmodified nanoclay. They have shown from and XRD analyses that organically modified clay shows better dispersion in the CPE matrix. This has been further substantiated from FTIR analysis, which proves an interaction between the CPE matrix and the clay intercalates. 

Xiao, J., Hu, Y., Wang, Z., Tang, Y., Chen, Z., and Fan, W., Preparation and characterization of poly(butylene terephthalate) nanocomposites from thermally stable organic-modified montmorillonite, Eur. Polym. J. (2005), 41,1030-1035. 

Vaia, R. A., Liu, W., and Koemer, H. Analysis of small-angle scattering of suspensions of organically modified montmorillonite Implications to phase behavior of polymer nanocomposites, J. Polym. Sci. B.Polym. Phys. (2003), 41, 3214-3236. 

F. Laoutid, P. Gaudon, J.M. Taulemesse, J.M. Lopez-Cuesta, J.I. Velasco, and A. Piechaczyk, Study of hydromagnesite and magnesium hydroxide based fire retardant systems for EVA containing organo-modified montmorillonite, Polym. Degrad. Stabil., 2006, 91 3074—3082. 

A detailed study of the interaction of hydrocarbons with cetyl trimethyl ammonium bromide modified montmorillonite has been done using Raman spectroscopy [82]. The quaternary salt was observed to be in a liquid-like state and it was concluded that interaction of organic compounds in this system is best classified as absorption. 

Polyvinyl chloride-montmorillonite nanocomposites were prepared either by in-situ suspension polymerisation using initiator- and comonomer-modified montmorillonite in the presence of free-radical initiators, such as AIBN, and compared. It was found that monomer conversion was low when the nanocomposites were prepared using initiator-modified montmorillonite. Exfoliated nanocomposites... 

Freitas, A. F., M. F. Mendes, and G. L. V. Coelho. 2009. Thermodynamic study on the adsorption of some organic acids from aqueous solutions by unmodified and modified montmorillonite clays. Chem. Eng. Commun. 196 824—840. 

A series of five nanocomposite elastomer systems were prepared for this study incorporating 0, 1, 2, 4 and 8% (on total resin mass) of the organically modified montmorillonite clay Cloisite 6A. The appropriate level of Cloisite was dispersed in a starting resin blend of OH terminated PDMS (M -77,000 and Mn -550 g mol in a 3 1 ratio) by a combination of mechanical mixing and ultrasonic processing to give a nano-dispersion of clay platelets. The blend was subsequently crosslinked with a stoichiometric level of tetrapropoxysilane (TPOS) in the presence of 5% diphenylmethylsilanol (DPMS) chain terminator and 5% tin(II) 2-ethylhexanoate catalyst, cured in an open mould at 65°C for twenty minutes, then removed from the mould and post cured for a further fifteen hours at 65°C to give an elastomeric mat. 

Shinde, A. B., Shrigadi, N. B., Bhat, R. P., Samant, S. D. Pinacol-Pinacolone Rearrangement on FeCIs Modified Montmorillonite K10. 

Tetrahedral and octahedral aluminium sheets in montmorillonite were studied by 27A1 MQ/MAS-NMR spectroscopy.405 19F, 27A1 and 29Si MAS-NMR spectra were used to characterise montmorillonite with various contents of Mg(II) or Zn(II) substituted for aluminium in octahedral sheets.406 Solid-state NMR spectra can be used to characterise and quantify the nanodispersion of variously modified montmorillonite clays in polystyrene matrices.407 27A1 and 29Si MAS-NMR spectra were used to follow hydration processes for Portland cement.408,409... 

Double-chain surfactants with two sulfonate groups were proposed for micellar elec-trokinetic chromatography (MEC) analysis of phenolic pollutants in water °. CE with ESI-MS detection was applied to the analysis of phenolic compounds in olive mill wastewaters. Quantitative analysis was performed in the negative SIM mode, using p-chlorophenol as internal standard. LOD ranged from 1 pg for 4-hydroxybenzaldehyde and protocatechuic acid (27) to 386 pg for vanillic acid (38) °". A modified montmorillonite served for SPE preconcentration of phenols, followed by EtOH desorption and CE end analysis . 

Wang, H. Zhao, T. Yan, Y. Yu, Y. Synthesis of resol-layered silicate nanocomposites by reaction exfoliation with acid-modified montmorillonite. J. Appl. Polym. Sci. 2004, 92, 791-797. 

Lim, S.K. Kim, J.W. Chin, L Kwon, Y.K. Choi, H.J. Preparation and interaction characteristics of organically modified montmorillonite nanocomposite with miscible polymer blend of poly(ethylene oxide) and poly(methyl methacrylate). Chem. Mater. 2002, 14, 1989-1994. 

Specific retention volume Vm (cm /g) and differential heat of adsorption Qa (kj/mol) for hydrocarbons adsorption on natural palygorskite, and natural and tetramethylammonium -modified montmorillonite at 150°C... 

A rather different behaviour is observed [32] for modified montmorillonite, possessing more labile and disordered structure as compared with fluorohectorite and vermiculite. 

Juang, R.S.. Lin, S.H., and Tsao, K.H., Mechanism of sorption of phenols from aqueous solutions onto surfactant-modified montmorillonite, 7. Colloid Interf. Sci., 254, 234, 2002. 

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