Preparation and characterization of hydrophilic organo-montmorillonites through incorporation of non-ionic polyglycerol dendrimers derived from soybean oil

• Soya-derived polyglycerols promotes the affinity of montmorillonite toward CO2.
• Polyglycerol based organo-montmorillonites show enhanced hydrophilic character.
• The OH groups of the polyglycerol dendrimer act as adsorption sites for CO2.
• Low dendrimer contents produce high CO2 adsorption capacity.
• Water appears to contribute to the CO2 retention.

Na-montmorillonite modification by the incorporation of hyperbranched polyglycerol dendrimers with average molecular weight 500, 1100 and 1700 g/mol and derived from soybean oil resulted in hybrid matrices with improved hydrophilic character and affinity toward carbon dioxide. Thermal analyses and thermal programmed desorption revealed that the dendrimer incorporation improved the amount of adsorbed water. The hydration grade was found to be proportional to the number of OH groups incorporated, and can double with the insertion of polyglycerol 500, 100 and 1700 at low dendrimer loadings. Inversely, higher dendrimer contents appeared to affect the hydrophilic character, favoring dendrimer aggregation into dense clusters, which reduces the number of OH groups accessible. This phenomenon was more accentuated with larger dendrimers. FTIR investigations also demonstrated that polyglycerol-based organoclays display improved interactions with water and/or carbon dioxide as compared to the starting material. The amount of adsorbed water was found to correlate with that of carbon dioxide, suggesting a certain contribution in CO2 retention.

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