ECTFE Research Articles

Development of a Novel ECTFE Melt-blown Nonwoven Material and Its Application in Oil-Water Separation

The removal of oil from water surfaces is crucial for protecting the environment and living organisms from the hazards posed by industrial oily wastewater and offshore oil spills. However, achieving enhanced mechanical robustness, corrosion resistance, and durability in oil-water separation membranes presents a significant challenge. In this study, poly(ethylene chlorotrifluoroethylene) (ECTFE) resin, a novel semicrystalline polymer material composed of alternating ethylene and chlorotrifluoroethylene molecules, was fabricated into melt-blown fabric (MB) by melt-blowing technology. By optimizing the side wind temperature, collector distance, roller speed, and hot air pressure, ECTFE MB with superior mechanical properties was established. Additionally, the obtained ECTFE MB exhibited excellent hydrophobicity with a water contact angle reaching 127.8°. The separation efficiency for various oil-water mixtures (oil phase including carbon tetrachloride, petroleum ether, dichloromethane, n-hexane, and isooctane) exceeded 99%. Furthermore, after 90 cycles of oil-water separation, ECTFE MB maintained high flux (72183.16 L m−2 h−1) and separation efficiency of 99.40% when carbon tetrachloride was used as oil phase. Notably, ECTFE MB demonstrated exceptional resistance to harsh environments, including strong acids, bases, and mild high temperature. The investigation of failure modes of ECTFE MB revealed that the primary failure mode of ECTFE MB was the disruption of the oil-water interface. The maximum water height that the ECTFE MB could withstand was 1376 mm. Consequently, ECTFE MB exhibit excellent mechanical properties, chemical stability, and cycling stability, indicating the potential application in the field of oil-water separation.

Effect of Chain Orientation on Coupling of Optical and Mechanical Anisotropies of Polymer Films

Polymer films have broad applications in different industries with specific requirements for their optical and mechanical properties. In mass production, processing conditions during film formation that apply forces and motions in various directions to the film tend to manifest preferred molecular chain orientation in the film microstructure, which unavoidably produces optical and mechanical anisotropies. In this paper, we investigate the effect of such macromolecular orientations on the optical and mechanical anisotropies of several polymer films, including polystyrene, poly(methyl methacrylate), poly(ethylene terephthalate), poly(ethylene naphthalate), poly(ether ether ketone), poly(ether sulfones), poly(ethylene chlorotrifluoroethylene), poly(phenylsulfone), and polycarbonate, at temperatures well below their respective glass transitions (Tg). The film mechanical responses, including elasticity, yielding, and post-yield behaviors, were obtained for the in- and out-of-plane directions utilizing tensile and nanoindentation testing methods, respectively. In addition, the net chain orientation within the films was evaluated by birefringence through analyzing the film optical refractive indices, which were verified and complemented by wide-angle X-ray scattering (WAXS) measurements. The results reveal a considerable quantitative correlation between the birefringence and the degree of elastic anisotropy and a qualitative correlation between the chain orientation and the film post-yield tensile instability (necking). These observations corroborate the interrelationship between the microstructure of polymer films and their optical and mechanical properties. In addition, they emphasize that process conditions can be selected to tune the optical and mechanical anisotropies to best serve the material performance in specific devices. We also propose an empirical equation to approximate the out-of-plane film stiffness based upon the optical and in-plane mechanical properties.

Fixed-bed adsorption of perfluorooctanoic acid from water by a polyamine-functionalized polychlorotrifluoroethylene-ethylene polymer coated on activated carbon

Perfluorooctanoic acid (PFOA) has received extensive attention because of its ubiquitous presence in the aqueous environmental phase and concerns of its impact on human health. An economical and effective adsorption method is in demand to help resolve the issue. In this study, a polyamine-functionalized polychlorotrifluoroethylene-ethylene polymer coated activated carbon (AC) was synthesized via a two-step reaction. The fluoropolymer based on the repeating unit ethylene-chlorotrifluoroethylene (ECTFE) was applied as the binding medium to connect activated carbon with polyethyleneimine (PEI). Hence a dual grafted activated carbon-based sorbent AC-ECTFE-PEI was generated. Through the adsorption evaluation of packed columns by on-line detection flow analysis, the optimum synthetic stoichiometry parameters to produce AC-ECTFE-PEI, based on the longest adsorption breakthroughs, were determined to be the 5:2 AC/ECTFE and 1:1 AC-ECTFE/PEI mass ratios. The new adsorbent has shown a strongly enhanced initial adsorption breakthrough to PFOA compared to AC, 270 min vs. 110 min, under the same adsorption conditions. AC-ECTFE-PEI was also characterized by attenuated total reflectance infrared spectroscopy, BET surface area analysis, and scanning electron microscopy. The functional group alterations during the reactions and the morphology information of the sorbent have also been elucidated. The Thomas, Adams-Bohart, and Yoon-Nelson models respectively were used to describe the adsorption behavior, indicating an PFOA adsorption capacity of 380 mg/g sorbent, 120 mg/L sorbent column, and a 50% average breakthrough time of 350 min for 100 mg/L PFOA removal, under a 1 mL/min flow rate and a 2 cm bed height. The regeneration study of AC-ECTFE-PEI of more than five adsorption-desorption cycles indicates good sustainability and stability. Both electrostatic and hydrophobic interactions of PFOA were justified using selective solvent compositon of the mobile phase as the two main adsorption mechanisms. The electrostatic forces of PFOA on AC-ECTFE-PEI, AC-ECTFE, and AC were also evaluated by their zeta-potential values.

Corrosion behavior and protection mechanism of carbon steel coated with ethylene chlorotrifluoroethylene (ECTFE)

Corrosion behavior and protection mechanism of carbon steel coated with ethylene chlorotrifluoroethylene (ECTFE)

Preparation, Modification, and Application of Ethylene-Chlorotrifluoroethylene Copolymer Membranes.

Ethylene-chlorotrifluoroethylene (ECTFE) was first commercialized by DuPont in 1974. Its unique chemical structure gives it high heat resistance, mechanical strength, and corrosion resistance. But also due to these properties, it is difficult to prepare a membrane from it by the nonsolvent-induced phase separation (NIPS) method. However, it can be prepared as a microfiltration membrane using the thermally induced phase separation (TIPS) method at certain temperatures and with the selection of suitable solvents, and the use of green solvents is receiving increasing attention from researchers. The surface wettability of ECTFE membranes usually needs to be modified before use to strengthen its performance to meet the application requirements, usually by graft modification and surface oxidation techniques. This paper provides an overview of the structure of ECTFE and its preparation and modification methods, as well as recent advances in its application areas and prospects for the future methods of preparing high-performance ECTFE membranes.

Preparation of non-woven supported ECTFE membrane by cast-coating method for membrane distillation

This work presents a novel preparation method, based on cast-coating, of a non-woven supported low melting point (LMP) poly (ethylene chlorotrifluoroethylene) (ECTFE) (Halar®) membrane. In particular, a LMP ECTFE dope solution was prepared via thermally induced phase separation (TIPS) method. Diethyl adipate(DEA) was used as solvent and diethylene glycol (DEG) was used as coagulation bath. Three types of non-woven material were used as support and the prepared membranes were characterized by SEM, pore size, porosity, contact angle, etc. Suitable membranes were selected and tested in pure water membrane distillation (MD) process, and also in 0.6 M NaCl solution to assess the recovery ability of the membrane. These prepared membranes were also compared with a commercial polypropylene (PP) membrane in terms of MD performance. The membranes showed a flux from 5 to 7 L/m2 h at the feed temperature of 55 °C and the salt rejection was above 99.9% when 0.6 M NaCl solution was used as feed, thus indicating them as promising candidates for the MD process.

Creating Ultrahigh and Long‐Persistent Triboelectric Charge Density on Weak Polar Polymer via Quenching Polarization

AbstractTo achieve high charge density for the triboelectric polymer is a crucial task for fabricating triboelectric nanogenerators (TENGs). This work has developed a quenching polarization (QP) method to create ultrahigh and long‐persistent triboelectric charge on the triboelectric polymer with weak dipole polarity. The Ethylene chlorotrifluoroethylene copolymer (ECTFE) film can reach a charge density of 391 µC m−2 in the vertical contact mode by using this QP treatment, which is 200% higher than the result achieved by the most widely used method of corona polarization. The mechanism of the improvement through QP on the triboelectric properties is studied on the basis of the polarization induced grain refinement and interfacial trapping. The QP‐treated ECTFE can maintain ultra‐high charge density for both solid‐solid and solid‐liquid TENG. More interestingly, the charge induced by QP treatment is so persistent that it produces a recoverable discharging phenomenon for solid‐liquid TENG, which has never been observed before. This QP method provides a different approach for fabricating high‐performance triboelectric materials, while the QP‐induced changes in crystallization and tribo‐charge density can help to complete the physical understanding of the electrification mechanism of triboelectric polymer.

Hydrophobic Membrane for Water Recovery from Humid Gas by Membrane Condenser: Effects of Membrane Properties on Recovered Water Quality

Two hydrophobic porous ethylene-chlorotrifluoroethylene (ECTFE) membranes quenched in water and air were fabricated by thermally induced phase separation and used for water recovery from ammonia-containing humid gas via vapor condensation. The ECTFE membranes were further hydrophobically modified to enhance their condensation performance. The condensate water quality of the modified membrane significantly improved. The mechanisms of the NH3 contamination in the condensate water were discussed. Surface hydrophobic modification slightly increased the flux and recovery stabilities of the membranes. However, the modification also increased the membrane surface roughness, which adversely affects the vapor condensation and droplet evolution on the membrane surface and reduced the recovered water quality. From the material perspective, desirable porous membranes for vapor condensation should have high surface hydrophobicity and smoothness and reasonably large pore sizes. The reasonably large pore sizes would promote noncondensable gaseous contaminants (e.g., ammonia) to go through the membrane, thereby improving the recovered water quality.

Isothermal and Non-Isothermal Crystallization Kinetics of Poly(ethylene chlorotrifluoroethylene).

The isothermal (IT) and non-isothermal (NIT) crystallization kinetics, morphology, and structure of poly(ethylene chlorotrifluoroethylene) (ECTFE) were investigated via differential scanning calorimetry (DSC), polarized optical microscopy (POM), and wide-angle X-ray diffraction (XRD). The Avrami equation could well describe the overall IT crystallization process of ECTFE, and, furthermore, the overall crystallization rate decreased at higher crystallization temperatures (Tc). The equilibrium melting point for ECTFE was found to be 238.66 °C. The activation energies for IT and NIT crystallization were determined as −137.68 and −120.54 kJ/mol, respectively. The Jeziorny model fitted well with the initial stages of NIT melt crystallization, while deviations from linearity in the later stages of the process were due to the collisions of spherulites. Spherulites of ECTFE organized in a hexagonal crystal system were found. The relative crystalline degree of ECTFE under NIT conditions was about 54.55%, and this decreased with the increase in cooling rate. Moreover, the Ozawa and Mo models were suitable for modeling the overall NIT crystallization process of ECTFE.

Ethylene chlorotrifluoroethylene/hydrogel-based liquid-solid triboelectric nanogenerator driven self-powered MXene-based sensor system for marine environmental monitoring

Triboelectric nanogenerators (TENGs) have great application prospects in self-powered detection system. In this paper, a wave-driven liquid-solid TENG was developed to construct a self-powered sensing system for marine environmental monitoring. The TENG was constructed with ethylene chlorotrifluoroethylene (ECTFE) film and ionic hydrogel electrodes to harvest wave energy. The peak-to-peak value of open-circuit voltage and powered density from the TENG can reach up to 332 V and 1.85 W/m2, respectively. The self-powered MXene/TiO2/SnSe sensor driven by the TENG was prepared for SO2 gas detection, which has an excellent response (ΔU/Ua = 170 % @ 30 ppm) and is 14 times larger than that of the resistive sensor. The gas-sensing improvement mechanism was discussed in detail using ternary p-m-n heterojunction and density functional theory simulation. A self-powered marine environment monitoring system was developed to further demonstrate the application potential of the prepared TENG and sensor. Sensor signals from the self-powered system can be transmitted to smartphones and upper modules to monitor temperature, humidity, SO2 concentration, water surface height and other environmental factors in real time. In addition, the temperature and humidity error correction of the gas sensor was realized by integrating and processing the data of the sensor system with the back propagation neural network model.

Fabrication and characterization of ECTFE hollow fiber membranes via low-temperature thermally induced phase separation (L-TIPS)

Poly (ethylene chlorotrifluoroethylene) (ECTFE) hollow fiber membranes were fabricated by using low-temperature thermally induced phase separation (L-TIPS) method with the addition of composite powder which composed of a variety of soluble and insoluble microparticles. The formation mechanism of membrane structure was evaluated by a thermodynamic phase diagram of the dope solution with different ECTFE concentration. The influence of composite powder addition on the morphology, structure and performance of membranes was studied. It could be seen that ECTFE hollow fiber membranes prepared with composite powder had thinner dense skin layer, bicontinuous microporous structure, and presented superior porosity, permeability and mechanical properties. The salt rejection rate achieved 98.8% with permeate flux of 10.8 L m−2 h−1 in submerged vacuum membrane distillation (SVMD) experiment. Furthermore, the membranes exhibited well thermal and chemical resistance properties in harsh treatments.

110th Anniversary: Liquid Separation Membranes Based on Nanowire Substrates for Organic Solvent Nanofiltration and Membrane Distillation

Ceramic nanowire-based flat porous membranes allow development of organic–inorganic membranes. Two types of surface modifications of alumina nanowire-based membranes were implemented. The first one involved reaction of hydroxyl groups on an alumina surface with silicone oil at a higher temperature, developing a grafted coating yielding a nonporous or a porous hydrophobic membrane. The hydrophobicity was verified via a contact angle comparable to that of a porous hydrophobic ethylene chlorotrifluoroethylene membrane. The membrane porosity was demonstrated by running vacuum membrane distillation with a 1 wt % salt-containing brine. The process yielded satisfactory water vapor flux with 98% salt rejection. The silicone oil’s reaction with the alumina surface could also block the pores, yielding a nonporous membrane for organic solvent nanofiltration (OSN). Interfacial polymerization was also carried out on the porous nanowire membrane to yield a nonporous polyamide membrane. The developed membrane was tested...

ECTFE membrane fabrication via TIPS method using ATBC diluent for vacuum membrane distillation

Poly (ethylene chlorotrifluoroethylene) (ECTFE) membrane presents interesting properties for microfiltration (MF) and membrane distillation (MD). In this paper, ECTFE is prepared via thermally induced phase separation (TIPS) process using acetyl tributyl citrate (ATBC) as an environmentally friendly diluent. Phase diagram of the ECTFE/ATBC system is measured, and the effects of ECTFE concentration and quenching bath temperature on the membrane structure, properties and performance are investigated, by characterizing with scanning electron microscope (SEM), pure water flux, contact angle, mechanical properties, mean pore size and porosity. The results show that the ECTFE membranes prepared with ATBC as diluent possessed spherulite structure, high hydrophobicity and liquid entry pressure of water (LEPw), promising permeate flux, salt rejection and mechanical strength in vacuum membrane distillation (VMD). The permeate flux reached to 22.3 L/(m2.h) with salt rejection rate of 99.9%. These results indicated that ECTFE membranes prepared with green diluent ATBC is an interesting candidate for VMD operation.

Stability enhancement of GaInP/GaAs/Ge triple-junction solar cells using Al2O3 moisture-barrier layer

A method to enhance the operational stability of GaInP/GaAs/Ge triple-junction (III-V) solar cells is proposed. To accomplish this, plasma-enhanced atomic layer deposition (PEALD) was employed, thereby forming a thin Al2O3 film as a moisture barrier layer. As observed, creation of a 50 nm Al2O3 layer demonstrated a water-vapor transmission rate (WVTR) of nearly 1.71 × 10−2 g/m2-day at 45 °C and 100% RH. Subsequent to Al2O3 deposition, solar cells were laminated with ethylene-vinyl acetate (EVA) and ethylene chloro-trifluoroethylene (ECTFE) films and exposed to conditions of 85 °C and 85% RH for 1000 h. As observed, when encapsulated within the 50 nm thin Al2O3 film, the III-V solar cells demonstrated greater stability over the said 1000 h period. On the other hand, III-V solar cells not encapsulated within the said Al2O3 films demonstrated an approximately 25% reduction in maximum power. Analysis results reveal that the observed degradation in III-V solar cell performance under high humidity conditions can be attributed to the oxidation of GaAs, which causes damage of the middle junction, and hence, drop in shunt resistance (RSH). Overall, III-V solar cells encapsulated within 50 nm Al2O3 demonstrated less than 1% drop in the power-conversion efficiency after 1000 h.

Electrophoretic deposition of dielectric film on stimulation electrodes for the use in intraoperative neuromonitoring

Abstract Electrophoretic deposition (EPD) is a material processing technology which uses direct current (DC) voltage to deposit thin layers on a metallic substrate. EPD is a promising coating technology for medical devices due to its advantages such as thin homogenous layers and a broad range of usable substrates. The objective of this paper is to demonstrate how EPD can be deployed successfully to apply an insulation layer on a stimulation electrode. The Mapping suction probe by inomed Medizintechnik GmbH, Germany, was coated in this investigation. The unique feature of this product is that it combines both a surgical vacuum and a stimulation probe and is used for brain tumour resection. As for the insulation layer, ethylene chlorotrifluoroethylene (ECTFE) was chosen because of its good dielectric and biocompatible properties. ECTFE particles (Halar®6514, Solvay Specialty Polymer, Italy) were mixed with a solvent (Novec™ 7100DL Engineered Fluid, 3M™) to form a suspension. The coating process was partly automatized to ensure good repeatability and reproducibility. For coating, the stimulation probe was immersed in the suspension so that the counter electrode, a stainless-steel net, surrounded it equidistantly. A heat treatment of the coated device in an oven (FED56, Binder, Germany) was required afterwards to melt the deposited polymer particles. After the heat treatment, a glossy black layer (layer thickness 42 μm) was observed on the substrate. A smooth and homogenous surface confirmed that the coating is suitable for surgical application. However, due to a high evaporation rate of the solvent, the ratio of particles and solvent changes and the coating process will have to be controlled in the future to achieve a stable process. Further advantages of EPD such as short processing time, straightforward process flow and scalability enables high production quantities which is attractive for industrial application. EPD might be a promising coating technology for medical devices in the future.

Nanoparticle filtration through microporous ECTFE membrane in an alcoholic solution

Abstract 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.

Surface Oxidation of Ethylenechlorotrifluoroethylene (ECTFE) Membrane for the Treatment of Real Produced Water by Membrane Distillation.

Modification of ethyleneechlorotrifluoroethylene (ECTFE) membranes by simple surface oxidation was reported in the present investigation in order to induce thin hydrophilic layer on hydrophobic membrane surface for the treatment of real produced water (PW). FTIR spectra indicates the appearance of hydrophilic functional groups (–OH and –COOH) on the membrane surface due to modification, while water contact angle, zeta potential measurement, EDX, XPS analysis confirmed the presence of O functionalized hydrophilic groups on the surface. The effect of modification temperature and the time of surface oxidation on the performance of the resulting membranes were studied systematically, which revealed that induction of optimized hydrophilicity can successfully reduce the organic fouling. However, too much hydrophilic surface induces polar/electrostatic interaction resulting salt deposition on membrane surface. A simple on site cleaning procedure was demonstrated to be successful for the treatment PW for at least three consecutive cycles of membrane distillation (MD).

Synthesis and characterization of Halar® polymer coating deposited on titanium substrate by electrophoretic deposition process

Halar®, an ethylene chlorotrifluoroethylene (ECTFE) thermoplastic polymer, can be considered as an ideal protection coating material for medical application, because of its high purity and unique combination of the mechanical and chemical properties. In this study, Halar® polymer powder particles are deposited onto titanium substrate by the means of electrophoretic deposition (EPD). Differential scanning calorimetry was used to measure thermal characteristics of the raw Halar® powders including glass transition temperature (Tg), melting temperature (Tm) and melting enthalpy (∆Hm). A high crystallinity value was determined for the raw polymer powders by differential scanning calorimetry analysis. Additionally, the effect of heat treatment on Tg, Tm and crystallinity of the polymer are evaluated at different heating temperatures. It was found that heat-treatment of the Halar® powder at the temperature of 260 °C (above its melting temperature) results in increasing of Tg, Tm and crystallinity of this thermoplastic polymer. Thus, after deposition thermal treatment temperature was performed at 260 °C for 15 min which may improve the adhesion of the coating to the substrate and its mechanical properties. Atomic force microscopy (AFM) and scanning electron microscopy (SEM) were used to assess the quality and surface morphology of Ti coated with Halar® polymer. The deposited coating showed a high quality, smooth and homogenous microstructure without any cracks or holes. Nanomechanical properties (hardness and elastic modulus) of the deposited polymer coating were also determined using the nanoindentation technique. Moreover, a comparison is drawn between the fatigue behavior of uncoated and polymer coated Ti specimens by a three-point bend test. The results indicated a blunt crack tip and a higher fatigue strength of Halar® polymer coated Ti.

Styrene grafted ethylene chlorotrifluoroethylene (ECTFE‐g‐PSSA) protonic membranes: Preparation, characterization, and transport mechanism

The main goal of the present work is the development of partially fluorinated, low‐cost proton exchange membranes. The styrene grafted onto commercial ethylene chlorotrifluoroethylene (ECTFE) membranes using solution grafting technique, and after that the membranes were sulfonated. Diluting styrene on ECTFE with a solvent mixture of methanol plus methylene chloride (1:1) was highly effective in promoting the grafting reaction as indicated by the increase in the degree of grafting (DG) to 21.3% compared to other solvents. The DG in ECTFE membranes increased with an increase in the monomer concentration up to 60% and then declined. Fourier transform infrared spectroscopic analysis confirmed grafting and sulfonation onto ECTFE films. The maximum value of proton conductivity for ECTFE‐g‐PSSA film with DG = 21.3% was observed to be 141 mS cm−1, which is also higher than those of Nafion 212 membrane. Furthermore, the activation energy of ECTFE‐g‐PSSA membranes was obtained ranging from 8.27 to 9.726 kJ mol−1. So both proton transport mechanisms (hopping and vehicle) have been commonly accepted. The mobility of the charge carriers calculated from proton conductivity data has robust dependence on the grafting yield and temperature. Moreover, the tensile strength and elongation at break ratio decreases with the increase in DG. The water and methanol uptakes increase up to 0.97% and 30%, respectively, for the highest DG value. Finally, the ECTFE‐g‐PSSA has lower cost and higher conductivity they could be better used instead of Nafion in direct methanol fuel cells.

Effects of Tri-n-octylamine with or without Diluents on Microporous Ethylene Chlorotrifluoroethylene Membranes

Microporous ethylene chlorotrifluoroethylene (ECTFE) membranes are expected to become industrially useful. Its solvent resistance is important in applications involving solvent microfiltration, organic synthesis, and membrane solvent extraction (MSX). Recent characterizations of microporous ECTFE membrane after exposure to different liquid media and radiation, indicated that pure tri-n-octylamine (TOA) does have some effect. However, it is used in MSX with diluents, e.g., xylene. Therefore, many material and porous-structure characterization techniques and dead-end microfiltration were employed to study solvent-treatment effects on ECTFE membranes exposed to ethanol, xylene, xylene80/TOA20, and pure TOA. Membrane-surface roughness of virgin, ethanol-soaked, and TOA-soaked membranes indicated TOA-soaked membranes were the roughest, followed by ethanol-soaked and virgin ones. Bubble-point-pressure based maximum pore diameters (dmax) of solvent-treated membranes were: dmax,TOA > dmax,Xylene/TOA > dmax,Xylene...