In the last couple of years, there has been particularly growing interest worldwide in exploring ways of finding suitable solutions to clean up oil spills and deal with industrial oily wastewater through use of nanomaterials. Key for the success of these materials is a high separation capacity, with resistance to oil fouling, and that are easily recyclable. Oil/water separation is an interfacial challenge, and novel materials designed to possess special wettability have different interaction and affinity for oil and water, thus can realize the separation. Until now, researches in this field all focus on materials with both hydrophobic and oleophilic properties. However, the oil-removing type of materials is easily fouled even blocked up by oils because of their intrinsic oleophilic property. A novel superhydrophilic and underwater superoleophobic hydrogel coated mesh can selectively separate water from oil/water mixtures effectively and without any extra power.
Notwithstanding all the buzz about renewable energy sources, the dirty facts are that coal accounts for 41% of electricity production worldwide. Since, realistically, coal will be a mainstay of electricity generation for many years to come, research into more environmentally friendly use of coal energy is picking up steam. One technology for more efficient power production centers around the solid oxide fuel cell (SOFC). Especially gasified carbon fuel cells offer great prospects for the most efficient utilization of a wide variety of carbonaceous solids fuels, including coal, biomass, and municipal solid waste. Researchers have now developed a self-cleaning technique that could allow solid oxide fuel cells to be powered directly by coal gas at operating temperatures as low as 750 degrees Celsius.
Water treatment is important for human consumption and environmental protection. Non-trivial purification of water involves removal of toxic ions, organic impurities, microbes and their by-products as well as scooping oil spills. The removal of organic contaminants from water is a major industrial concern. The challenging goal here is to detect, decompose and remove contaminants present usually in low concentrations. Towards this end, different types of sorbent materials have been developed to date, the most common being activated carbon. Though the use of activated carbon is still considered to be one of the best method, the disposal of adsorbed contaminants along with the adsorbent is a major concern. Researchers in India have recently come up with an innovative method for organic pollutant removal from waste water.
Several manufacturers are incorporating nano-sized particles of silver into, among other things, garments like socks and shirts to kill bacteria that cause odor. But does the silver stay in the socks or T-shirts? And what happens to it if it washes out? Also, what is the climate footprint of producing the required nanosilver? To answer these questions, a group of researchers have performed a cradle-to-grave life cycle assessment to compare nanosilver T-shirts with conventional T-shirts with and without biocidal treatment. For their assessment, the team used conventional T-shirts treated with triclosan, a commonly applied biocide to prevent textiles from emitting undesirable odors. The results show significant differences in environmental burdens between nanoparticle production technologies.
In the wake of the BP oil spill in the Gulf of Mexico we published a general overview of the wide variety of nanomaterials and nanotechnologies that offer significant promise for oil spill cleanup and recovery. One problem with many existing solutions though is that they are one-offs, i.e. one they absorb oil they can't be re-used and need to be disposed of (which could in turn create secondary pollution effects). Ideally, any oil absorbent material used during ocean oil spills should be reusable and with special wettability that could controllably capture and release oil pollution repeatedly. Addressing this issue, researchers have now created an underwater water/solid interface inspired by fish scales. The surface of this new material shows superamphiphobicity in air and superoleophilicity under water, allowing it to be repeatedly used to capture and collect oil droplets in water.
There is a general perception that nanotechnologies will have a significant impact on developing 'green' and 'clean' technologies with considerable environmental benefits. However, the environmental footprint created by today's nanomanufacturing technologies are conflicting with the general perception that nanotechnology environmentally benign. It actually appears that certain nanomaterial production technologies are quite dirty and also have a considerable energy footprint. Determining the full environmental impact of nanomaterials requires a full life cycle assessment. A recent paper takes a look at the material and energy intensity of fullerene production. It finds that the embodied energy of all fullerenes are an order of magnitude higher than most common chemicals.
The recent oil spill in the Gulf of Mexico is widely acknowledged to be among the worst ocean oil spills in world history. Inevitably, the spill has once again raised serious concerns worldwide about the likely environmental impact of such catastrophic oil spills caused by oil tanker accidents at sea or mishaps during loading and unloading of oil from tankers at seaports. Numerous solutions have been proposed for dealing with the problem of oil spills. Conventional techniques are not adequate to solve the problem of massive oil spills. In recent years, nanotechnology has emerged as a potential source of novel solutions to many of the world's outstanding problems. Although the application of nanotechnology for oil spill cleanup is still in its nascent stage, there has been particularly growing interest in exploring ways of finding suitable solutions to clean up oil spills through use of nanomaterials.
Global warming, caused by a build-up of greenhouse gases, in particular carbon dioxide, in the atmosphere, has led to numerous proposals on how to capture and store CO2 in order to mitigate the damaging emissions from fossil fuels. Today we take a look at carbon sequestration and subsequent storage in geological formations (geosequestration) - a proposal that is already being tested on a large scale. The idea behind coal-bed geosequestration is that you inject a huge amount of carbon dioxide into deep unmined coal seams. Due to strong adsorption forces, the carbon dioxide will be adsorbed in coal. It will not be desorbed and gradually transform to solid rocks. Moreover the technology is already developed and in use for oil and gas mining. However, the fundamental problem is so-called adsorption-induced deformation of coal or any other porous material.