Semipermeable membrane is a type of biological or synthetic, polymeric membrane that allows certain molecules or ions to pass through it by osmosis. The rate of passage depends on the pressure, concentration, and temperature of the molecules or solutes on either side, as well as the permeability of the membrane to each solute. Depending on the membrane and the solute, permeability may depend on solute size, solubility, properties, or chemistry. How the membrane is constructed to be selective in its permeability will determine the rate and the permeability. Many natural and synthetic materials which are rather thick are also semipermeable. One example of this is the thin film on the inside of an egg.
An artificial membrane, or synthetic membrane, is a synthetically created membrane which is usually intended for separation purposes in laboratory or in industry. Synthetic membranes have been successfully used for small and large-scale industrial processes since the middle of the twentieth century. A wide variety of synthetic membranes is known. They can be produced from organic materials such as polymers and liquids, as well as inorganic materials. Most commercially utilized synthetic membranes in industry are made of polymeric structures. They can be classified based on their surface chemistry, bulk structure, morphology, and production method. The chemical and physical properties of synthetic membranes and separated particles as well as separation driving force define a particular membrane separation process. The most commonly used driving forces of a membrane process in industry are pressure and concentration gradient. The respective membrane process is therefore known as filtration. Synthetic membranes utilized in a separation process can be of different geometry and flow configurations. They can also be categorized based on their application and separation regime. The best known synthetic membrane separation processes include water purification, reverse osmosis, dehydrogenation of natural gas, removal of cell particles by microfiltration and ultrafiltration, removal of microorganisms from dairy products, and dialysis.
Gas mixtures can be effectively separated by synthetic membranes made from polymers such as polyamide or cellulose acetate, or from ceramic materials.
An oxygen concentrator is a device that concentrates the oxygen from a gas supply by selectively removing nitrogen to supply an oxygen-enriched product gas stream. They are used industrially, to provide supplemental oxygen at high altitudes, and as medical devices for oxygen therapy.
Jean M.J. Fréchet is a French-American chemist and professor emeritus at the University of California, Berkeley. He is best known for his work on polymers including polymer-supported chemistry, chemically amplified photoresists, dendrimers, macroporous separation media, and polymers for therapeutics. Ranked among the top 10 chemists in 2021, he has authored nearly 900 scientific paper and 200 patents including 96 US patents. His research areas include organic synthesis and polymer chemistry applied to nanoscience and nanotechnology with emphasis on the design, fundamental understanding, synthesis, and applications of functional macromolecules.
Thin-film composite membranes are semipermeable membranes manufactured to provide selectivity with high permeability. Most TFC's are used in water purification or water desalination systems. They also have use in chemical applications such as gas separations, dehumidification, batteries and fuel cells. A TFC membrane can be considered a molecular sieve constructed in the form of a film from two or more layered materials. The additional layers provide structural strength and a low-defect surface to support a selective layer that is thin enough to be selective but not so thick that it causes low permeability.
Menachem Elimelech is the Sterling Professor of Chemical and Environmental Engineering at Yale University. Elimelech is the only professor from an engineering department at Yale to be awarded the Sterling professorship since its establishment in 1920. Elimelech moved from the University of California, Los Angeles (UCLA) to Yale University in 1998 and founded Yale's Environmental Engineering program.
Nanotube membranes are either a single, open-ended nanotube(CNT) or a film composed of an array of nanotubes that are oriented perpendicularly to the surface of an impermeable film matrix like the cells of a honeycomb. 'Impermeable' is essential here to distinguish nanotube membrane with traditional, well known porous membranes. Fluids and gas molecules may pass through the membrane en masse but only through the nanotubes. For instance, water molecules form ordered hydrogen bonds that act like chains as they pass through the CNTs. This results in an almost frictionless or atomically smooth interface between the nanotubes and water which relate to a "slip length" of the hydrophobic interface. Properties like the slip length that describe the non-continuum behavior of the water within the pore walls are disregarded in simple hydrodynamic systems and absent from the Hagen–Poiseuille equation. Molecular dynamic simulations better characterize the flow of water molecules through the carbon nanotubes with a varied form of the Hagen–Poiseuille equation that takes into account slip length.
Edward L. Cussler is an American chemical engineer and professor in the department of chemical engineering and materials science at the University of Minnesota. He is internationally known for his work in fluid mechanics, transport phenomena, and gas separations, especially in the areas of membranes and gas sorption. Cussler is an author of more than 250 academic papers, dozens of patents, and five books including the acclaimed text: “Diffusion”. He has served as director, vice president and president of the American Institute of Chemical Engineers, and he presented the AIChE Institute Lecture in 2014. Cussler and his wife Betsy, a former teacher at Edina High School, are long-time residents of Minneapolis, Minnesota.
Dr. Jerry Y.S. Lin is a Regents' Professor of Chemical Engineering in School for Engineering of Matter, Transport and Energy at the Arizona State University in Tempe, Arizona, US. He publishes papers under the names “Y.S. Lin” or "Jerry Y.S. Lin". From 2006 to 2009, he served as the Chemical Engineering Department Chair at Arizona State University, and now directs the Membrane and Energy Laboratory at ASU.
A membrane is a selective barrier; it allows some things to pass through but stops others. Such things may be molecules, ions, or other small particles. Membranes can be generally classified into synthetic membranes and biological membranes. Biological membranes include cell membranes ; nuclear membranes, which cover a cell nucleus; and tissue membranes, such as mucosae and serosae. Synthetic membranes are made by humans for use in laboratories and industry.
Benjamin S. Hsiao is an American materials scientist and educator. He served as the vice-president for research and chief research officer at Stony Brook University from May 2012 to December 2013.
Timothy P. Lodge is an American polymer scientist.
Eugenia Kumacheva is a University Professor and Distinguished Professor of Chemistry at the University of Toronto. Her research interests span across the fields of fundamental and applied polymers science, nanotechnology, microfluidics, and interface chemistry. She was awarded the L'Oréal-UNESCO Awards for Women in Science in 2008 "for the design and development of new materials with many applications including targeted drug delivery for cancer treatments and materials for high density optical data storage". In 2011, she published a book on the Microfluidic Reactors for Polymer Particles co-authored with Piotr Garstecki. She is Canadian Research Chair in Advanced Polymer Materials. She is Fellow of the Royal Society (FRS) and a Fellow of the Royal Society of Canada (FRSC).
Michael Tsapatsis is an American chemical engineer and materials scientist. Tsapatsis is the 36th Bloomberg Distinguished Professor at Johns Hopkins University in the Department of Chemical and Biomolecular Engineering. Prior to this position he was the Amundson Chair (2008–present), professor (2003-present), and McKnight Presidential Endowed Chair (2017–present) in the department of chemical engineering and Materials Science at the University of Minnesota. Prior to his appointment at the University of Minnesota, Tsapatsis was an associate professor at the University of Massachusetts Amherst.
Polymers of intrinsic microporosity (PIMs) are a unique class of microporous material developed by research efforts led by Neil McKeown, Peter Budd, et al. PIMs contain a continuous network of interconnected intermolecular voids less than 2 nm in width. Classified as a porous organic polymer, PIMs generate porosity from their rigid and contorted macromolecular chains that do not efficiently pack in the solid state. PIMs are composed of a fused ring sequences interrupted by Spiro-centers or other sites of contortion along the backbone. Due to their fused ring structure PIMs cannot rotate freely along the polymer backbone, ensuring the macromolecular components conformation cannot rearrange and ensuring the highly contorted shape is fixed during synthesis.
Arthi Jayaraman is an Indian-American scientist who is the Centennial Term Professor for Excellence in Research and Education at the University of Delaware. Her research considers the development of computational models to better understand polymer nanocomposites and biomaterials. Jayaraman was elected Fellow of the American Physical Society in 2020.
Melissa Ann Grunlan is an American scientist and academic. She is Professor and Holder of the Charles H. and Bettye Barclay Professorship in the Department of Biomedical Engineering at Texas A&M University. She holds courtesy appointments in the Departments of Chemistry and Materials Science & Engineering. Her research focuses on the development of polymeric biomaterials for regenerative engineering and medical devices.
Robert L. McGinnis is an American scientist, technology entrepreneur, and inventor who has founded a number of technology companies including Prometheus Fuels, Mattershift and Oasys Water.
David John Lohse is a retired ExxonMobil materials scientist known for contributions on thermodynamics of mixing, nanocomposites for controlling permeability, neutron scattering of polymers, rheology of polymers.
