Structural Characterization of the Plasticizers’ Role in Polymer Inclusion Membranes Used for Indium (III) Transport Containing IONQUEST® 801 as Carrier

Abstract

Polymer inclusion membranes containing cellulose triacetate as support, Ionquest® 801 ((2–ethylhexyl acid) -mono (2–ethylhexyl) phosphonic ester) as extractant, and 2NPOE (o–nitrophenyl octyl ether) or TBEP (tri (2–butoxyethyl phosphate)) as plasticizers were characterized using several instrumental techniques (Fourier Transform Infrared Spectroscopy (FT–IR), Reflection Infrared Mapping Microscopy (RIMM), Electrochemical Impedance Spectroscopy (EIS), Differential Scanning Calorimetry (DSC)) with the aim of determining physical and chemical parameters (structure, electric resistance, dielectric constant, thickness, components’ distributions, glass transition temperature, stability) that allow a better comprehension of the role that the plasticizer plays in PIMs designed for In(III) transport. In comparison to TBEP, 2NPOE presents less dispersion and affinity in the PIMs, a plasticizer effect at higher content, higher membrane resistance and less permittivity, and a pronounced drop in the glass transition temperature. However, the increase in permittivity with In (III) sorption is more noticeable and, in general, PIMs with 2NPOE present higher permeability values. These facts indicate that In (III) transport is favored in membranes with chemical environment of high polarity and efficiently plasticized. A drawback is the decrease in stability because of the minor affinity among the components in 2NPOE–PIMs.

Ion-selective membrane modified microfluidic paper-based solution sampling substrates for potentiometric heavy metal detection

“…S6 and Table S2,† the FTIR spectra indicated that the modification of the PS6.0 paper substrate demonstrated multiple additional functional groups (as compared to the unmodified paper substrate) that are correlated to the ISM components applied. 41–43 Detailed FTIR analysis is available in ESI section 2.1 †…”

“…S6 and Table S2, † the FTIR spectra indicated that the modification of the PS6.0 paper substrate demonstrated multiple additional functional groups (as compared to the unmodified paper substrate) that are correlated to the ISM components applied. [41][42][43] Detailed FTIR analysis is available in ESI section 2.1. † Determination of lead(II) in complex environmental samples using ISM-modified paper substrates coupled with Pb 2+ -ISEs Overall, the Pb 2+ ion activities determined by the ISEs coupled with ISM-modified paper substrates (PS6.0) were found to be comparable to the total lead concentration determined by ICP-OES (Fig.…”

A green compliant hand-held selective electrode device for monitoring active pharmaceuticals and the kinetics of their degradation

“…To account for solvent effects, the implicit polarizable continuum model (PCM) 52 was employed where a single point calculation using the gas phase optimized geometries were computed with the standard Pople type 6-311 + + g(d,p) basis set for all the atoms to calculate the solvation free energies. Since the medium employed experimentally, 2-nitro phenyl octyl ether, having a dielectric constant ε ¼ 23–24 53 – 56 is unavailable as a solvent in the Gaussian code, the solvent 1-nitro propane, having a dielectric constant of ε ¼ 23.7 was employed in these PCM calculations. The Gibbs free energies in solution were calculated for CX6, DG and complex between them as the sum of the gas-phase free energy and the solvation free energy , as previously reported 18 , 20 , 51 .…”

Effect of Plasticization/Annealing on Thermal, Dynamic Mechanical, and Rheological Properties of Poly(Lactic Acid)

“…Several strategies have been explored to address the limitations of PLA, including stereocomplexation, plasticization, filler incorporation, and polymer blending [1,13,17,18]. Plasticization is a cost-effective method for enhancing the flexibility of PLA by increasing free volume, reducing intermolecular forces, and improving molecular mobility [19][20][21]. Various plasticizers, including poly(ethylene glycol) (PEG) [22][23][24][25][26][27][28][29][30][31], poly(propylene glycol) (PPG) [32,33], oligomeric lactic acid (OLA) [6,34,35], citrate esters [36][37][38], and vegetable oils [39][40][41][42], have been utilized to blend with PLA.…”