Porous polyethersulfone hollow fiber membrane in gas–liquid contacting processes

Spinning of Polysulfone Hollow Fiber Membranes Using Constant Dope Solution Composition: Viscosity Control via Temperature

The dope solution viscosity is an important parameter that largely determines the properties of hollow fiber membranes. In the literature available today, the change in viscosity is carried out only by changing the quantitative and/or qualitative dope solution compositions. However, such an important spinning parameter as temperature should significantly affect the dope solution viscosity. For the first time, the influence of the dope solution viscosity of a constant composition on polysulfone hollow fiber membrane properties was studied. The hollow fiber membranes were obtained by the phase separation method induced by a non-solvent (NIPS). The change in the dope solution temperature was carried out in the temperature range of 17-27 °C, providing a dope solution viscosity range of 34.3-21.6 Pa∙s. This work shows that even in such a narrow temperature range, the properties of polysulfone hollow fiber membranes change significantly. With a decrease in the viscosity in this temperature range, the wall thickness of the hollow fiber membrane decreases by 2.8 times; the permeance for the individual gases He and CO₂ increases by 1.6-1.8 times, respectively; the ideal selectivity decreases by 1.12 times; the mean flow pore size increases by 1.63 times; and the surface porosity increases about 3 times.

Zinc phosphate nanoparticles: A review on physical, chemical, and biological synthesis and their applications

Nanotechnology is considered one of the emerging fields of science that has influenced diverse applications, including food, biomedicine, and cosmetics. The production and usage of materials with nanoscale dimensions like nanoparticles are attractive parts of nanotechnology. Among different nanoparticles, zinc phosphate nanoparticles have attracted attention due to their biocompatibility, biosafety, non-toxicity, and environmental compatibility. These nanoparticles could be employed in various applications like anticorrosion, antibacterial, dental cement, glass ceramics, tissue engineering, and drug delivery. A variety of physical, chemical, and green synthesis methods have been used to synthesize zinc phosphate nanoparticles. All these methods have some limitations along with certain advantages. Chemical approaches may cause health risks and environmental problems due to the toxicity of hazardous chemicals used in these techniques. Moreover, physical methods require high amounts of energy as well as expensive instruments. However, biological methods are free of chemical contaminants and eco-friendly. This review is aimed to explore different methods for the synthesis of zinc phosphate nanoparticles, including physical, chemical, and more recently, biological approaches (using various sources such as plants, algae, and microorganisms). Also, it summarizes the practicable applications of zinc phosphate nanoparticles as anticorrosion pigment, dental cement, and drug delivery agents.

Preparation and characterization of poly(ether sulfone)/fluorinated silica organic–inorganic composite membrane for sulfur dioxide desulfurization

The highly hydrophobic poly(ether sulfone)/fluorinated silica (PES/fSiO2) organic–inorganic composite membrane for sulfur dioxide (SO2) desulfurization was prepared by incorporating the fSiO2 particles on the PES membrane via sol–gel process and fluorination. The formation of PES/fSiO2 organic–inorganic composite membrane was examined by attenuated total reflectance Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, thermal gravimetric analysis, field-emission scanning electron microscopy, and water contact angle. The experimental results showed that the fSiO2 inorganic layer was tightly bonded to the PES membrane surface through silane chemical reactions. The incorporation of the fSiO2 inorganic layer on the PES membrane surface increases the surface roughness and reduces the surface free energy because of the hydrophobic dodecafluoroheptyl-propyl-trimethoxysilane. The hydrophobicity of the PES/fSiO2 composite membrane was dramatically enhanced from 78.0° of PES membrane to 128.2° of PES/fSiO2 membrane. Compared with PES membrane, the desulfurization performance of PES/fSiO2 membrane was investigated. PES/fSiO2 organic–inorganic composite membrane indicated a reasonably stable SO2 absorption flux of 7.69E-4 mol/m2 s during the 240-min-long time operation.

Polyvinylidene fluoride hollow fiber mixed matrix membrane contactor incorporating modified ZSM-5 zeolite for carbon dioxide absorption

PVDF/ ZSM-5 hollow fiber mixed matrix membrane.