Swelling of 9 polymers commonly employed for solvent-resistant nanofiltration membranes: A comprehensive dataset

Abstract

The presence of a solvent in a dense polymeric nanofiltration membrane layer can affect the macromolecular dynamics of the polymer material and the mobility of the solvent penetrant molecules. In addition, even the affinity of the swollen material for the solvent molecules can be distinct from that of the pure polymer material. These effects can substantially affect the membrane's performance. This paper provides sorption and swelling data of 9 thin polymer films that are commonly used for organic solvent nanofiltration (P84, Matrimid, PEI, PAN, PES, PSf, PEBAX, PTMSP, PDMS) swollen by 10 common solvents (hexane, toluene, dichloromethane, ethyl acetate, methyl ethyl ketone, acetone, isopropanol, ethanol, methanol, water). The paper describes the swelling dynamics during short-term solvent exposure (0-8 h), assesses the stability upon long-term solvent exposure (up to 2 months), and provides quantitative data on the solvent volume fractions inside the swollen layers. Among the surprising findings are the glubbery behavior of PTMSP and the completely different response of PES and PSf to toluene exposure. The results of this work demonstrate three crucial findings relevant to organic solvent nanofiltration membranes and other applications: 1. For many polymers, the swelling changes over long timescales of up to 2 months and longer. Results obtained on short timescales do however not always allow for direct extrapolation to longer time scales. 2. Structural similarity of polymers does not guarantee similar swelling behavior. 3. Swelling behavior of solvents cannot be solely explained by classifying solvents into aprotic, polar aprotic and polar protic solvents. The results of this work can aid in constructing transport models and can help predicting polymer-solvent compatibility and membrane performance in OSN applications.

Prediction of Orthotropic Hygroscopic Swelling of Fiber-Reinforced Composites from Isotropic Swelling of Matrix Polymer

“…The matrix properties are easy to measure. Furthermore, they also may be found in literature for various polymers [28,32]. However, in some cases, the interfacial effects may not be negligible [33], many of the moisture-related properties of composites are known to be traceable to those of the matrix material [12,13].…”

“…Swelling strains of a composite and a matrix polymer should also be related to each other through a proper analysis [13,34]. Since swelling in polymers does not follow the ideal mixing law [2], i.e., the volume increase of the polymer is not equal to the volume of the absorbed water, and it is necessary to perform swelling experiments for the matrix polymer itself, or to find polymer CHE in the literature [28,32]. The composite swelling can then be analytically or numerically predicted from the swelling of the matrix polymer, as shown in this work.…”

Transient and Steady Pervaporation of 1-Butanol–Water Mixtures through a Poly[1-(Trimethylsilyl)-1-Propyne] (PTMSP) Membrane

“…Despite solutions of Fick's second law for non-uniform initial distribution being derived [52], the actual initial distribution depends, in the case of our experimental procedure, on the concentration dependence of the diffusivity, which is typically not known. Indeed, PTMSP is known to show highly anomalous sorption, swelling and diffusion [32][33][34]53]. We thus limited ourselves to studying the transient pervaporation of 1-butanol upon its first introduction into initially pure water (feed), i.e., to concentrations appropriate for continuous ISPR, and to comparing the retrieved diffusivity of 1-butanol with that determined from the measurement [44,45] of the kinetics of transient sorption of 1-butanol vapor in an initially degassed slab of the polymer.…”

Sorption‐assisted thermopervaporation method for organics recovery from ABE fermentation broth

“…The drawback of inorganic zeolite‐based materials is the irreversible interaction between the acids and reactive sites that might limit their application during long‐term operation. However, PTMSP demonstrates greater sorption and swelling for organic solvents in comparison with typically cross‐linked poly[dimethylsiloxane] . It is interesting to note that polymers of intrinsic microporosity, with PTMSP being a particularly prominent example, are considered as transition material between conventional polymers and microporous materials such as activated carbon or zeolites due to a sorption capacity of ten times and diffusion coefficients of 10 3 to l0 times greater than those observed in conventional glassy polymers .…”