A new study at the Ohio State University found that water filter pitches don’t all do an equal job of filtering harmful materials from water. The new study compared three popular brands in their ability to filter out microcystins from tap water. One brand did fine, the other two didn’t stop the microcystins, which get into the water during harmful algal blooms.
The study, which appears in Water Science Technology: Water Supply, found that the fastest filter made with coconut-based activated carbon could only remove about 50% (or less!) of the microcystins. While the slowest one, made from an active carbon blend, made microcystins undetectable in the water.
The researchers don’t specifically name any of the three bands, but they are all common and range in price from $15 to $50. Interested parties would be able to read the study, which does specifically name the features of each pitcher and their findings, and deduce from that data which brand of pitcher to buy if they want the best filtration.
It’s one of life’s little annoyances: that last bit of shampoo that won’t quite pour out of the bottle. Or the last bit of hand soap, or dish soap, or laundry detergent.
Now researchers at The Ohio State University have found a way to create the perfect texture inside plastic bottles to let soap products flow freely. They describe the patent-pending technology in a paper to appear in the journal Philosophical Transactions of the Royal Society on June 27.
The technique involves lining a plastic bottle with microscopic y-shaped structures that cradle the droplets of soap aloft above tiny air pockets, so that the soap never actually touches the inside of the bottle. The “y” structures are built up using much smaller nanoparticles made of silica, or quartz – an ingredient in glass—which, when treated further, won’t stick to soap.
The key is surface tension—the tendency of the molecules of a substance to stick to each other. Ketchup and other sauces are made mostly of water, and water molecules tend to stick to each other more than they stick to plastic. But surfactants – the organic molecules that make soap “soapy” – are just the opposite: They have a very low surface tension and stick to plastic easily.
With further development, the university hopes to license the coating technique to manufacturers—not just for shampoo bottles, but for other plastic products that have to stay clean, such as biomedical devices or catheters. They have already applied the same technique to polycarbonate, a plastic used in car headlights and smartphone cases, among other applications.
Scientists are getting closer to directly observing how and why water is essential to life as we know it.
A study in this week’s Proceedings of the National Academy of Sciences provides the strongest evidence yet that proteins – the large and complex molecules that fold into particular shapes to enable biological reactions – can’t fold themselves.
Rather, the work of folding is done by much smaller water molecules, which surround proteins and push and pull at them to make them fold a certain way in fractions of a second, like scores of tiny origami artists folding a giant sheet of paper at blazingly fast speeds.
Dongping Zhong, leader of the research group at The Ohio State University that made the discovery. It is a major step forward in the understanding of water-protein interactions and it answers a question that’s been dogging research into protein dynamics for decades.
The key to getting a good view of the interaction was to precisely locate optical probes on the protein surface, he said. The researchers inserted molecules of the amino acid tryptophan into the protein as a probe, and measured how water moved around it.
Co-authors on the study were Yangzhong Qin, a postdoctoral researcher, and Lijuan Wang, lab manager. The work was funded by the National Institutes of Health, and computing time was provided by OSC.