ABSTRACT
Relevant chemical separations for the petrochemical and chemical industries include the removal of aromatic hydrocarbons from aliphatics, the desulfurization and denitrification of fuels, and the separation of azeotropic mixtures containing alkanols. In an attempt to contribute to the development of novel technologies, the potentialities of imidazolium chloride ionic liquid (IL) mixtures as separation agents were investigated. Selectivities, capacities, and solvent performance indices were calculated through the activity coefficients at infinite dilution of organic solutes and water in the imidazolium chloride IL: [C8mim]Cl, [C12mim]Cl, and the equimolar mixture of [C4mim]Cl and [C12mim]Cl. Results show that the imidazolium chloride IL might be appropriately tailored for specific purposes, in which an increase in the proportion of cations containing larger alkyl chains tends to increase the overall affinity with organic solutes. The IL designer solvent concept was explored by comparing the IL equimolar mixture results with the intermediary [C8mim]Cl. The COSMO-RS thermodynamic model was also applied, showing it to be a promising tool for a fast qualitative screening of potential separation agents for specific separation processes.
ABSTRACT
Thermosensitive hydrogels based on chitosan/pectin (CS/Pec) and CS/Pec/gold nanoparticles (CS/Pec/AuNPs) were successfully prepared with different AuNP levels. Using a tilting method, gelation temperature was demonstrated to decrease when the amount of AuNPs increased and pectin concentrations decreased. The presence of AuNPs in the CS/Pec composite was evaluated via WAXS and UV-vis techniques, while SEM analysis assessed the average size of pores (350-600µm). All samples were extremely cytocompatible with many cell types, such as normal kidney epithelial cells (VERO cells), epithelial colorectal adenocarcinoma cells (HT-29 cells), HPV-16 positive human cervical tumour cells (SiHa cells), kidney epithelial cells (LLCMK2 cells) and murine macrophage cells (J774A1 cells). Cell viability assays using the MTT method upon mouse preosteoblastic cells (MC3T3-E1 cells) showed that CS/Pec and CS/Pec/AuNPs composites had the potential to foster proliferation and growth of bone cells, making them possible stimulators for reconstruction of bone tissues.
