Polytetrafluoroethylene (PTFE)/carbon black (CB) microporous membranes produced from PTFE/CB composite particles prepared by heterocoagulation process

Abstract

Polytetrafluoroethylene (PTFE)/carbon black (CB) microporous membranes with excellent properties were successfully prepared via heterocoagulation process and mechanical stretching method. Heterocoagulation was achieved using PTFE emulsion with 26% solid content, an intermediate product of the commercial PTFE dispersions with 60% solid content, and CB dispersions to prepare PTFE/CB composite particles by mechanical stirring, which is the unique content in this article. Furthermore, in order to obtain uniform distribution of CB particles within the membrane matrix as well as improve color uniformity and mechanical strength of the microporous membranes, CB was pretreated by a titanate coupling agent (NDZ-201). The PTFE/CB composite particles were then used to prepare the PTFE/CB microporous membranes via mechanical stretching operation. Several important properties of the prepared PTFE/CB microporous membranes, such as tensile strength, porosity, contact angles, morphology, and dynamic mechanical properties, were investigated. Results showed that the fabricated PTFE/CB microporous membranes possessed color uniformity, high tensile strength, and high hydrophobicity.

Capturing Polar and Nonpolar Particles with an Electroadhesive Device Using Interfacial and Orientational Polarization

“…Figure e shows the SEM image of Teflon particles, which had some transparency with a size of 35.5 μm. This was very similar to the other SEM image of PTFE/carbon black composite, which contained some transparency . There is a large size distribution between three particles.…”

“…This was very similar to the other SEM image of PTFE/carbon black composite, which contained some transparency. 36 There is a large size distribution between three particles. This seems to be directly correlated to the dielectrophoretic force, which is the movement of polarizable particles under a nonuniform electric field.…”

Plasma & Microwaves as Greener Options for Nanodiamond Purification: Insight Into Cytocompatibility

“…Here, the high fluorine content and the direct chemical bonding to the carbon surface [displacing H (Nesvizhevsky et al, 2018)] rendered this surface very similar to that of highly fluorinated polymers. The ZP value of −31.7 mV at pH 4.65 is nearly identical to that of a PTFE suspension (Zhang et al, 2017), and higher than that of PVDF (Anton Paar, 2019). Similar to the mentioned fluoropolymers, the strong negative ZP is based on the preferential adsorption of hydroxide ions on an inert non-ionic ND surface (Beattie, 2006).…”

Sintering process investigation during polytetrafluoroethylene hollow fibre membrane fabrication by extrusion method

“…These outstanding properties make PTFE hollow fibre membrane a very popular application in membrane contactor, 2 membrane distillation, 3 bioreactor, 4 membrane emulsification 5 and supporting membrane. 6 Polymeric hollow fibre membrane preparation, especially phase inversion process which is the most commonly applied membrane fabrication method, has been well studied in recent years. [7][8][9] Nevertheless, PTFE hollow fibre membrane cannot be fabricated directly by phase inversion process since it owns excellent solvent resistance, extremely high melting point and viscosity.…”