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Organic solvent filtration is an important industrial process. It is widely used in pharmaceutical manufacturing, chemical processing industry, semiconductor industry, auto assembly etc. Most of the particle filtration studies reported in open literature dealt with aqueous suspension medium. The current work has initiated a study of cross-flow solvent filtration behavior of microporous ethylene chlorotrifluoroethylene (ECTFE) membranes using 12 nm silica nanoparticles suspended in an aqueous solution containing 25% ethanol. In the constant pressure mode of operation of cross-flow microfiltration (MF), permeate samples were collected at different time intervals. The permeate particle size distribution (PSD) results for different experiments were identical. Particle agglomerates having less than 100 nm size can pass through the membrane; some fouling was observed. The governing fouling mechanisms for tests operated using 3.8×10−3 kg/m3 (3.8 ppm) at 6.9×103 Pag and 1.4×104 Pag were pore blocking. For tests conducted using 3.8×10−3 kg/m3 (3.8 ppm) at 27.6×103 Pag (4 psig) and 1.9×10−3 kg/m3 (1.9 ppm) at 6.9×103, 13.8×103 and 27.6×103 Pag (1, 2 and 4 psig), the mechanism was membrane resistance control. Less particles got embedded in membrane pores in experiments operated using suspensions with lower or higher particle concentrations with a higher transmembrane pressure. This is in good agreement with the values of the shear rate in the pore flow and scanning electron microscope images of the membrane after MF. In the dead-end mode of operation of solvent filtration using methanol, ethanol and 2-propanol, the permeate flux behavior follows Jmethanol > Jethanol > J2-propanol at all testing pressures. The values of permeance (kg/m2-s-Pa) determined from the slope of the linear plot of filtration flux vs. the applied pressure difference across the membrane, were 3.9×10−4, 2.3×10−4 and 3.0×10−5 for methanol, ethanol and 2-propanol, respectively. Further exploration was made on solvent sorption results reported earlier. The critical temperature of selected solvents shows a better correlation with solvent sorption rather than the solubility parameter.
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This content will become publicly available on February 10, 2027
Solvent Control Over Mechanistic Pathways of Ferrocene Intercalation in the Layered Host VOPO 4 ·2H 2 O
Understanding how solvents influence the mechanism of intercalation is essential to advancing layered materials for energy storage devices, catalysis, and molecular electronics. In this study, we explore intercalation into the layered vanadium phosphate host using ferrocene as the reducing agent and guest, revealing three distinct solvent-dependent mechanistic pathways that depend on the solvent-host interaction, ferrocene concentration, and product lattice energy. Different aliphatic organonitrile solvents, while they do not react directly with VOPO4•2H2O, can nevertheless affect the ratio between stage 1 and stage 2 products and a kinetics analysis suggests the two products follow different mechanistic pathways. In contrast to the aliphatic nitriles, primary alcohol molecules can directly insert into VOPO4•2H2O layers. With in-situ measurements, pre-intercalation of the alcohol, followed by co-intercalation of alcohol and the guest, are observed experimentally for the first time. A stage 1 phase is formed in 1-propanol, and a stage 2 phase is formed in ethanol, indicating the propanol-host interaction is moderate, allowing ferrocene to fully occupy the host layers, whereas the ethanol-host interaction is too strong to be completely expelled by the guest. These differences underscore the influence of solvent-host interactions during intercalation, enhancing understanding of solvent-assisted intercalation and its applications in hybrid materials.
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- Award ID(s):
- 2409400
- PAR ID:
- 10710851
- Publisher / Repository:
- American Chemical Society
- Date Published:
- Journal Name:
- Chemistry of Materials
- Volume:
- 38
- Issue:
- 3
- ISSN:
- 0897-4756
- Page Range / eLocation ID:
- 1049 to 1059
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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