Showing Spotlights 1 - 8 of 19 in category Nanofiltration (newest first):
Nanofluidic membranes based on two-dimensional materials are promising materials for next-generation water desalination and purification. For instance, pristine and chemically modified graphene oxide membranes (GOMs) effectively block organic dyes and nanoparticles as small as 9 Å. However, these nanomembranes fail to exclude smaller inorganic salt ions, which would be required to extract pure potable water from unconventional water sources such as, salt water, industrial waste water, and rain water. With a novel approach called planar heterogeneous interface desalination researchers can now achieve a high salt rejection rate close to 97%.
Mar 3rd, 2020
The ability of nanochannels to regulate transported substances in confined spaces is of great research interest in innovative applications, such as high-resolution sensing, filtering, and high-efficiency energy utilization. In the last area, research on nanochannels in energy-related areas continues to face challenges such as low efficiencies, complex preparation processes, and high fabrication costs. Overcoming these challenges is an important and difficult task in the field of energy conversion, energy conservation, and energy recovery.
Apr 10th, 2018
Researchers have developed a new separation membrane with 2D layered transition metal dichalcogenides (tungsten disulfide) for size-selective separation of small molecules of about 3 nm. The as-prepared WS2 membranes exhibit 5 times higher water permeance than graphene oxide membranes with similar rejection. To further improve the water permeance, they team employed ultrathin metal hydroxide nanostrands to create more fluidic channels while keeping the rejection rate of specific molecules unchanged.
Jun 17th, 2014
One of the problems with activated carbon is the disposal of adsorbed contaminants along with the adsorbent. Another concern is that its pores are often blocked during adsorption. By contrast, carbon nanotubes' (CNTs) open structure offers easy, undisrupted access to reactive sites located on nanotubes' outer surface. That's why researchers see CNTs as an attractive potential substitute for activated carbon. Researchers now have demonstrated that individual CNTs can be integrated into micrometer-sized colloidal particles without using a heavy or bulky particulate support.
May 27th, 2014
The development of sustainable, robust, energy-efficient and cost-effective water purification technologies is a challenging task. Conventional practices adopted for water purification suffer from certain limitations such as high cost, low adsorption capacity, generation of toxic sludge, etc. A possible solution to tackle this problem has been demonstrated by scientists in India. They developed nanotechnology-based water purification using nano-silica-silver composite material as antifouling, antimicrobial and dye adsorptive material.
May 6th, 2014
Micro- and nanoporous materials can widely be found in nature, be it zeolite minerals, cell membranes, or diatom skeletons. Researchers are developing artificial analogues of such materials, i.e. nanoporous materials, for industrial applications in areas such as catalysis, water purification, environmental clean-up, molecular separation and proton exchange membranes for fuel cells. Manufacturing nanosieves with straight nanopores is still challenging, especially when the pore size is less than 10 nm. Researchers in Korea have now developed a novel material and fabrication technique that allows easy fabrication of nanosieves with sub-10 nm nanopores with straight pore-structure. With it, controlling the pore size from sub-nm to 5 nm becomes very easy.
Aug 24th, 2012
Among various technologies, reverse osmosis membranes have been widely used for water reclamation. However, external energy required and high operational pressure used make reverse osmosis membrane water reclamation processes energy intensive - not exactly an advantage given the rising cost of energy and the negative climate impact of fossil fuels. Today, forward osmosis is a well-recognized osmotic process for producing clean water with a bright future as it uses a natural phenomenon and does not require any operational pressure hence it saves large amount of energy compared with reverse osmosis process. Researchers now describe a novel forward osmosis membrane that presents remarkable properties superior over conventional membrane support layers.
Jun 24th, 2011
One of the problems in modern separation science and technology is the challenge of separating gaseous mixtures that consist of very similar particles, for example, hydrogen isotope mixtures; mixtures of noble gases; etc. The problem arises because small particles such as hydrogen isotopes share similar size and shape (only their molecular mass is different). While this problem can be technically solved, currently available separation methods such as thermal diffusion, cryogenic distillation, and centrifugation, tend to be time and energy intensive. New theoretical work now shows that narrow carbon nanotubes (CNTs) seem to be an attractive alternative. By using CNTs as nanoporous molecular sieves, the separation of parahydrogen molecules from mixtures of classical particles at cryogenic temperatures seems to be possible.
Apr 14th, 2011