J Colloid Interface Sci
December 2021
Hypothesis: The air-solution interface of supersaturated calcium hydrogen carbonate (Ca(HCO)) represents the highest saturation state due to evaporation/CO-degassing, where calcite crystals are expected to nucleate and grow along the interface. Hence, it should be possible to form a free-standing mineral-only calcium carbonate (CaCO) microfilm at the air-solution interface of Ca(HCO). The air-solution interface of phosphate buffered saline (PBS) could represent a phase boundary to introduce a hybrid microstructure of CaCO and carbonate-rich dicalcium hydroxide phosphate (carbonate-rich hydroxylapatite).
View Article and Find Full Text PDFPolymerization-induced self-assembly of 2-hydroxypropyl methacrylate is conducted in water and water/MeOH using a CO -responsive macroRAFT agent in the form of a statistical copolymer comprising N,N-diethylaminoethyl methacrylate (DEAEMA) and poly(ethylene glycol) methyl ether methacrylate (M = 475 g mol ). Pressurization with CO leads to protonation of DEAEMA units within the stabilizer block, thereby offering a means of adjusting the charge density of the coronal layer. It is demonstrated that a wide range of tunable particle morphologies are accessible by simply varying the CO pressure during polymerization in the range of 10-45 bar.
View Article and Find Full Text PDFThe catalytic polymerization of ethylene is performed in water pressurized with CO . The size of the initial monomer droplets and of the resulting polymer particles can be varied by simply changing the CO pressure. Furthermore, at identical ethylene partial pressure, the polymerizations performed in the presence of CO are significantly faster than in its absence.
View Article and Find Full Text PDFThe synthesis of polymeric nanocapsules in the approximate diameter range 40-100 nm (TEM/SEM) using catanionic surfactant vesicle templates stabilized by subcritical CO2 is demonstrated. Near equimolar aqueous solutions of the surfactants sodium dodecyl sulfate (SDS) and dodecyltrimethylammonium bromide (DTAB) experienced immediate vesicle destabilization and precipitation in the absence of CO2. However, pressurization with CO2 (5 MPa) dramatically enhanced the stability of the initial vesicles, and enabled swelling of the bilayers with hydrophobic monomers via diffusion loading (loading of monomers into preformed bilayers).
View Article and Find Full Text PDFThis paper investigates the effect of using recycled fiber (RCF) in newsprint production on the effluent quality and its treatability using membrane operations for internal and external recycling and reuse. Increased chemical usage in RCF for deinking had significant impact on the silica and sodium content of the effluent which in turn limits the membrane's operation. Increasing the RCF content from 0% to 50% is estimated to increase the silica content from 4 to 119mgL(-1) and sodium content from 135 to 500mgL(-1).
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