Accurate monitoring of gas mixture transport kinetics through polymeric membranes

Polysulfone membranes exhibit resistance to high temperature with low manufacturing cost and high efficiency in the separation process. The composition of gases is an important step that estimates the efficiency of separation in membranes. As membrane types are currently becoming in demand for CO2/CH4 segregation, polysulfone will be an advantageous alternative to have in further studies. Therefore, research is undertaken in this study to evaluate two solvents: chloroform (CF) and tetrahydrofuran (THF). These solvents are tested for casting polymeric membranes from polysulfone (PSF) to separate every single component from a binary gas mixture of CO2/CH4. In addition, the effect of gas pressure was conducted from 1 to 10 bar on the behavior of the permeability and selectivity. The results refer to the fact that the maximum permeability of CO2 and CH4 for THF is 62.32 and 2.06 barrer at 1 and 2 bars, respectively. Further, the maximum permeability of CF is 57.59 and 2.12 barrer at 1 and 2 bars, respectively. The outcome selectivity values are 48 and 36 for THF and CF at 1 bar, accordingly. Furthermore, the study declares that with the increase in pressure, the permeability and selectivity values drop for CF and THF. The performance for polysulfone (PSF) membrane that is manufactured with THF is superior to that of CF relative to the Robeson upper bound. Therefore, through the results, it can be deduced that the solvent during in-situ synthesis has a significant influence on the gas separation of a binary mixture of CO2/CH4.

Download Full-text

Sorption and Diffusion of CO2/N2 in gas mixture in thermally-rearranged polymeric membranes: A molecular investigation

Journal of Membrane Science ◽

10.1016/j.memsci.2017.01.025 ◽

2017 ◽

Vol 528 ◽

pp. 135-146 ◽

Cited By ~ 26

Author(s):

Carmen Rizzuto ◽

Alessio Caravella ◽

Adele Brunetti ◽

Chi Hoon Park ◽

Young Moo Lee ◽

...

Keyword(s):

Polymeric Membranes ◽

Gas Mixture ◽

Molecular Investigation ◽

And Diffusion

Download Full-text

Modeling of CO2/CH4 gas mixture permeation and CO2 induced plasticization through an asymmetric cellulose acetate membrane

RSC Advances ◽

10.1039/c5ra23506e ◽

2016 ◽

Vol 6 (20) ◽

pp. 16561-16567 ◽

Cited By ~ 6

Author(s):

M. Saberi ◽

S. A. Hashemifard ◽

Ali. A. Dadkhah

Keyword(s):

Mathematical Model ◽

Cellulose Acetate ◽

Polymeric Membranes ◽

Gas Mixture ◽

Cellulose Acetate Membrane ◽

Mixed Gases ◽

And Diffusion

A mathematical model for permeation and diffusion of mixed gases in glassy polymeric membranes in the presence of plasticization was derived.

Download Full-text

SEM/FESEM imaging of lamellar structures in melt extruded polyethylene films

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100130341 ◽

1992 ◽

Vol 50 (2) ◽

pp. 1142-1143

Author(s):

R.T. Chen ◽

M.G. Jamieson ◽

R. Callahan

Keyword(s):

Imaging Techniques ◽

Membrane Surface ◽

High Stress ◽

Extrusion Direction ◽

Polymeric Membranes ◽

Scanning Tunneling ◽

Tunneling Microscopy ◽

Crystalline Polymers ◽

Lamellar Structures ◽

Resolution Imaging

“Row lamellar” structures have previously been observed when highly crystalline polymers are melt-extruded and recrystallized under high stress. With annealing to perfect the stacked lamellar superstructure and subsequent stretching in the machine (extrusion) direction, slit-like micropores form between the stacked lamellae. This process has been adopted to produce polymeric membranes on a commercial scale with controlled microporous structures. In order to produce the desired pore morphology, row lamellar structures must be established in the membrane precursors, i.e., as-extruded and annealed polymer films or hollow fibers. Due to the lack of pronounced surface topography, the lamellar structures have typically been investigated by replica-TEM, an indirect and time consuming procedure. Recently, with the availability of high resolution imaging techniques such as scanning tunneling microscopy (STM) and field emission scanning electron microscopy (FESEM), the microporous structures on the membrane surface as well as lamellar structures in the precursors can be directly examined.The materials investigated are Celgard® polyethylene (PE) flat sheet membranes and their film precursors, both as-extruded and annealed, made at different extrusion rates (E.R.).

Download Full-text

Low-voltage field-emission SEM of polymeric membranes for glucose biosensors

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100161862 ◽

1990 ◽

Vol 48 (3) ◽

pp. 860-861

Author(s):

Lorna K. Mayo ◽

Kenneth C. Moore ◽

Mark A. Arnold

Keyword(s):

Glucose Sensor ◽

Low Voltage ◽

Glucose Sensors ◽

Polymeric Membranes ◽

Artificial Endocrine Pancreas ◽

Self Monitoring ◽

Conducting Materials ◽

Insulin Dependent ◽

Living Tissues ◽

Voltage Scanning

An implantable artificial endocrine pancreas consisting of a glucose sensor and a closed-loop insulin delivery system could potentially replace the need for glucose self-monitoring and regulation among insulin dependent diabetics. Achieving such a break through largely depends on the development of an appropriate, biocompatible membrane for the sensor. Biocompatibility is crucial since changes in the glucose sensors membrane resulting from attack by orinter action with living tissues can interfere with sensor reliability and accuracy. If such interactions can be understood, however, compensations can be made for their effects. Current polymer technology offers several possible membranes that meet the unique chemical dynamics required of a glucose sensor. Two of the most promising polymer membranes are polytetrafluoroethylene (PTFE) and silicone (Si). Low-voltage scanning electron microscopy, which is an excellent technique for characterizing a variety of polymeric and non-conducting materials, 27 was applied to the examination of experimental sensor membranes.

Download Full-text