A novel method for synthesis of polymeric nano-objects <italic>via</italic> polymerization-induced self-assembly in a CO₂-expanded medium has been developed.

Polymerization-induced self-assembly of 2-hydroxypropyl methacrylate is conducted in water and water/MeOH using a CO2 -responsive macroRAFT agent the form statistical copolymer comprising N,N-diethylaminoethyl (DEAEMA) poly(ethylene glycol) methyl ether (M n = 475 g mol-1 ). Pressurization with leads to protonation DEAEMA units within stabilizer block, thereby offering means adjusting charge density coronal layer. It demonstrated that wide range tunable particle morphologies are accessible...

Solubilities of p-hydroxybenzoic acid (p-HBA) and mixtures the para ortho isomers have been determined in supercritical carbon dioxide at 318 328 K for pressures range 101−203 bar. The solubility p-HBA (p-HBA/CO2 binary system) is 2 orders magnitude lower than system o-HBA. However, measurements undertaken with an equilibrium chamber mixed demonstrate a strong enhancement p-HBA. Furthermore, was found to be independent composition chamber. ternary (p-HBA/o-HBA/CO2) data were correlated using...

Studies of the extraction solid mixtures with supercritical fluids (SCFs) demonstrate that solute−solute interactions in SCF phase can be significant. To further explore such interactions, solubilities various hydroxybenzoic acid (HBA) isomers CO2 were determined. Solubility data are reported at pressures ranging from 101 to 203 bar and for temperatures 318 K 328 K. Significant solubility enhancements observed m-HBA p-HBA systems containing ortho isomer. The degree enhancement obtained is...

Abstract The reversible addition–fragmentation chain transfer polymerization of methyl methacrylate mediated by 2‐cyanoprop‐2‐yl dithiobenzoate (CPDB) in bulk (60 and 70 °C) suspension (70 was studied, both systems, a good control the molecular weight polydispersity observed. Stable polymerizations were carried out over range CPDB concentrations, with increasing concentration, particle size index produced polymer decreased. former ascribed to lower viscosities monomer droplets at low...

A novel environmentally friendly low-energy emulsification method that relies on pressurization with CO2 to low pressure has been applied reversible addition–fragmentation chain transfer (RAFT) polymerization of styrene-in-water miniemulsions the anionic surfactant Dowfax 8390. This circumvents traditional high-energy homogenization, and over a certain range, transparent miniemulsion is formed. RAFT styrene using benzyldodecyl trithiocarbonate aqueous phase initiator VA-044 was carried out...

The mechanism of catalytic chain transfer polymerization with methyl methacrylate was studied in a range media. reaction supercritical CO2 found to be significantly enhanced compared similar experiments toluene or bulk methacrylate. results are consistent diffusion-controlled rate-determining step the process cobaloxime catalysts. gaslike viscosities medium result an approximate coefficient (ktr) 108 L mol-1 s-1: order magnitude higher than values obtained conventional organic solvents.

Solubility data are presented for a mixture of o-hydroxybenzoic acid (o-HBA) and m-HBA in supercritical CO2 doped with 3.5 mol % methanol. The were measured at 318 328 K pressures the range 101−201 bar. Some new solubility pure methanol-doped also presented. solubilities HBA isomers enhanced considerably addition methanol to CO2. However, enhancement is strongly affected by spatial arrangement their functional groups (steric effect). There appears be preferential interaction between solutes...

Vapor−liquid equilibrium data for carbon dioxide + methyl methacrylate are reported at temperatures of 308, 313, 323, and 333 K pressures in the range 1−8 MPa. The corresponding measurements volumetric expansion liquid phase also presented. A linear relationship is observed between pressure liquid-phase composition all considered. Peng−Robinson equation state provides a satisfactory correlation vapor−liquid data. It shown that isotherms coincide when plotted as function composition. high...

The critical temperature and pressure for binary mixtures of ethane containing n-alkanes (C5 to C10) at low concentrations (up 5.2 mol %) have been determined. A visual technique was used where the observation mixture opalescence followed by appearance a vapor−liquid meniscus in constant volume sight gauge observed. absolute errors measurements were ±2 K ±0.5 bar, respectively, with an estimated relative error ±1.5% composition organic compounds used. using correlation based on theory...

Abstract A method for evaluating solid–liquid equilibria of mixtures lipids and carbon dioxide (CO 2 ) under pressure is developed presented in this article. Experimental measurements by high‐pressure differential scanning calorimetry (DSC) are performed to determine transition temperatures as a function composition. These data used develop simplified approach thermodynamic modeling, that is, correlation prediction, the equilibria. The model requires fewer pure component properties...

Nitroxide-mediated radical polymerization based on TEMPO has been performed for methyl methacrylate under conditions of CO2-expanded monomer at 7 MPa and 90°C. The fraction propagating radicals lost due to disproportionation with nitroxide, a well-known problem in NMP methacrylates, decreased the presence CO2. This is consistent deactivation between nitroxide proceeding more rapidly lower viscosity induced by However, ceased relatively low conversions approximately 19% both without CO2,...