Nanomaterials research conducted at the University of Buffalo could lead to the development of new solutions for an age-old public health problem: how to keep bacteria out of drinking water.
To the naked eye, both the water molecules and the bacteria are invisible - objects so tiny that they are measured on a scale of nanometers. However, at the microscopic level the two are very different in regards to their size. The width of a single water molecule is less than one nanometer, while the width of some of the smallest bacteria reaches several hundreds of nanometers.
A research team from the University of Buffalo succeeded in synthesizing a new type of nanomembrane consisting of pores with a width of about fifty-five nanometers - a size large enough so that water molecules can pass through it easily, and too small for bacteria to succeed in this.
The pore size is the largest ever achieved in scientific history using block copolymers, which have special properties that ensure the pores are evenly spaced, said researcher Javid Rzayev, the chemist who led the study. The research findings were published in the scientific journal Nano Letters.
"These materials offer new opportunities for their use in filtration membranes," the researcher noted. "Commercial membranes have disadvantages in terms of density and the uniformity of the size of the pores. In the membranes composed of block copolymers, the distribution of pores is very dense, and the pores are uniform in size."
"Although there is extensive research in this field, what our research team was able to achieve was to expand the field of available pores to those with a diameter of fifty nanometers, and which could not be obtained in the past using methods based on block copolymers," the researcher notes. "Increasing the diameter of the pores will allow the water to flow faster, a characteristic from which savings in costs and time will be derived. At the same time, pores with a diameter of 100-50 nanometers are still small enough to prevent the passage of bacteria through them."
The special quality of the innovative nanomembrane originates from the type of polymers used by the scientists. Block copolymers consist of two types of polymers that repel each other, and at the same time are bound together into one copolymer.
When many block copolymers are mixed, their mutual repulsion leads them to arrange themselves in an ordered and alternating manner. The result of this process, known as self-organization, is a solid nanomembrane consisting of two types of polymers. In order to produce evenly spaced pores, the researchers simply moved one of the polymer types apart. The rather extensive size of the pores is a result of the unique structure of the original co-polymer block, which was prepared from bottle brush-like molecules.
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Peace and blessings.
First - is there a reference to Ami Bachar's words?
Also - what types of water can be filtered using this system?
Best regards,
borrowed.
The nano membrane should be treated as one part of a filtration system adapted to the needs. The definition of needs begins with the characterization of the source material and the required result. The problem of "bio neutralization" is the biggest problem in water sources in remote areas. It should be remembered that the size of (small) bacteria is about 25 nanometers and the size of a virus is about 15 nanometers. From this it follows that we need 2 more at least one grade whose "nano fruits" will be smaller than 10 nano. And there are such products.
And as Ami pointed out absolutely beautiful.
It is certainly very beautiful and I am sure that it will be used many more, but it is worth noting that in nature in every cubic centimeter of water there can be hundreds of millions of bacteria of different sizes. There can also be other things of large sizes that will not pass through the membrane. On the one hand, as said in the original - this is good, because this way we keep this nuisance away from our drinking water. On the other hand, what will prevent these membranes from closing almost immediately upon contact with water? I know the problem from filtering sea water with GFP filters that have very large holes of several hundreds of microns. Through such a filter of 5 cm square you can pass about a liter of water until it gets clogged - depending on the density of the plankton. It is interesting how they intend to deal with rapid clogging of the membrane.
Greetings friends,
Ami Bachar