Modeling the Phase Behavior of PEO−PPO−PEO Surfactants in Carbon Dioxide Using the PC-SAFT Equation of State: Application to Dry Decontamination of Solid Substrates

Abstract

The phase behavior of several commercially available poly(ethylene oxide)-b-poly(propylene oxide)-b-poly(ethylene oxide) block copolymers (PEO−PPO−PEO or Pluronics L) in compressed carbon dioxide has been investigated within the framework of dry nuclear decontamination. For this purpose, cloud points have been measured in the pressure and temperature range from P = (10 to 40) MPa and from T = (293 to 338) K, respectively. To find a reliable method for surfactant selection, the perturbed-chain statistical association fluid theory (PC-SAFT) equation of state (EoS) has been applied to model the experimental data. The pure-component and the respective homopolymer + CO2 binary interaction parameters have been fitted to liquid densities and to homopolymer + CO2 binary equilibrium data. The phase behavior of Pluronics L copolymers as a function of concentration, molar mass, and copolymer composition has been predicted very accurately using a constant PEO−PPO binary interaction parameter k PEO-PPO = 0.007. The PC-SAFT model was also successfully applied to Pluronics R copolymers (PPOPEOPPO), although a different k PEO-PPO = −0.018 was required to match the experimental data. The model predictions have shown that Pluronics L copolymers with molar mass M < 2750 g·mol−1 and a PEO mass fraction in the copolymer of less than 30 % have sufficiently low cloud-point pressures and are therefore the most suitable for the decontamination process.

Influence of excipients on solubility and dissolution of pharmaceuticals

“…In this work, the PC-SAFT pure-component parameters of indomethacin, naproxen, water and the selected excipients were taken from literature (Fuchs et al, 2006;Held et al, 2013;Prudic et al, 2015aPrudic et al, , 2014aStoychev et al, 2009) and are summarized in Table 2.…”

Experimental density and PC-SAFT modeling of Krytox® (perfluoropolyether) at pressures to 275MPa and temperatures to 533K

“…For polymer systems, these parameters are typically obtained by fitting the equation to experimental density data or to a combination of polymer density data and phase equilibria data for polymer-solvent mixtures [17][18][19][20]. The PC-SAFT EOS has been successfully used to predict the thermodynamic properties of many different kinds of polymer systems [17][18][19][20][21][22][23][24][25][26]. In certain instances group contribution (GC) methods have been used with the PC-SAFT EOS to estimate values for the three pure component parameters [17,27] rather than fitting the EOS to experimental data.…”

Effects of several inter-molecular interactions on the inclusion between methyl substituted β-cyclodextrin and some linear macromolecule in supercritical carbon dioxide medium

“…Due to the low solubility of TMBCD and the guest in scCO 2 medium [31][32][33], the total composition of the product should be the same with the corresponding physical mixture, thus the fraction of complex TMBCD relative to total TMBCD in the product could be derived.…”

“…After some carbon dioxide was added into the reactor, the inclusion was somewhat improved. As some PPO (M w * 425) molecules may dissolve in scCO 2 medium [31,32] and not contacted with the MBCD matrix, the real reactant ratio may be lower for the inclusion at 1:2 initial ratio. At 1:4 reactant ratio, more than 70% MBCD was threaded onto the polymer chain in the product ( Table 2).…”

“…[26][27][28][29][30]); but has not been used in the inclusion between macrocyclic molecule and linear polymer now, due to the low solubility of normal polymer and the inflexibility of some cyclodextrin matrix in this medium [31][32][33].…”