{"id":254281,"date":"2021-05-19T23:51:48","date_gmt":"2021-05-19T20:51:48","guid":{"rendered":"https:\/\/en.buradabiliyorum.com\/unexpected-black-swan-defect-discovered-in-soft-matter-for-first-time\/"},"modified":"2021-05-19T23:51:48","modified_gmt":"2021-05-19T20:51:48","slug":"unexpected-black-swan-defect-discovered-in-soft-matter-for-first-time","status":"publish","type":"post","link":"https:\/\/buradabiliyorum.com\/en\/unexpected-black-swan-defect-discovered-in-soft-matter-for-first-time\/","title":{"rendered":"#Unexpected ‘Black Swan’ defect discovered in soft matter for first time"},"content":{"rendered":"

“#Unexpected ‘Black Swan’ defect discovered in soft matter for first time<\/strong>”<\/p>\n

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In new research, Texas A&M University scientists have for the first time revealed a single microscopic defect called a “twin” in a soft-block copolymer using an advanced electron microscopy technique. This defect may be exploited in the future to create materials with novel acoustic and photonic properties.<\/p>\n


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“This defect is like a black swan\u2014something special going on that isn’t typical,” said Dr. Edwin Thomas, professor in the Department of Materials Science<\/a> and Engineering. “Although we chose a certain polymer for our study, I think the twin defect will be fairly universal across a bunch of similar soft matter systems, like oils, surfactants, biological materials and natural polymers. Therefore, our findings will be valuable to diverse research across the soft matter field.”<\/p>\n

The results of the study are detailed in the Proceedings of the National Academy of Sciences<\/i> (PNAS<\/i>).<\/p>\n

Materials can be broadly classified as hard or soft matter. Hard materials, like metal alloys and ceramics, general<\/a>ly have a very regular and symmetric arrangement of atoms. Further, in hard matter, ordered groups of atoms arrange themselves into nanoscopic building blocks, called unit cells. Typically, these unit cells are comprised of only a few atoms and stack together to form the periodic crystal. Soft matter can also form crystals consisting of unit cells, but now the periodic pattern is not at the atomic level; it occurs at a much larger scale from assemblies of large molecules.<\/p>\n

In particular, for an A-B diblock copolymer, a type of soft matter, the periodic molecular motif comprises of two linked chains: One chain of A units and one chain of B units. Each chain, called a block, has thousands of units linked together and a soft crystal forms by selective aggregation of the A units into domains and B units into domains that form huge unit cells compared to hard matter.<\/p>\n

Another notable difference between soft and hard crystals is that structural defects have been much more extensively studied in hard matter. These imperfections can occur at a single atomic location within material, called a point defect. For example, point defects in the periodic arrangement of carbon atoms in a diamond due to nitrogen impurities create the exquisite “canary” yellow diamond. In addition, imperfections in crystals can be elongated as a line defect or spread across an area as a surface defect.<\/p>\n


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