{"id":11309,"date":"2017-01-19T06:18:08","date_gmt":"2017-01-19T06:18:08","guid":{"rendered":"http:\/\/revoscience.com\/en\/?p=11309"},"modified":"2017-01-20T07:14:34","modified_gmt":"2017-01-20T07:14:34","slug":"the-power-of-attraction","status":"publish","type":"post","link":"https:\/\/www.revoscience.com\/en\/the-power-of-attraction\/","title":{"rendered":"The power of attraction"},"content":{"rendered":"

Hybrid organic-inorganic materials can self-assemble into tiny doughnut-like structures.<\/strong><\/em><\/span><\/p>\n

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Coordination-driven self-assembly leads to the formation of micrometer-scale toroids.
\u00a9 2016 KAUST Xavier Pita<\/figcaption><\/figure>\n

Engineered nanometer- and micrometer-scale structures have a vast array of uses in electronics, sensors and biomedical applications. Because these are difficult to fabricate, KAUST researchers are trying a bottom-up philosophy, which harnesses the natural forces between atoms and molecules such that microstructures form themselves.<\/span><\/p>\n

This approach, a departure from the usual top-down approach, involves the etching<\/a> away of material to leave the desired sculpted structure behind; however, because this approach can be tricky, expensive and time consuming, KAUST researchers became motivated to find a new approach.<\/span><\/p>\n

Associate Professor of Chemical Science Niveen Khashab and her team and colleagues from the Imaging and Characterization Core Lab and the Max-Planck-Institute of Colloids and Interfaces in Germany <\/a>demonstrated this bottom-up approach in the self-assembly of microscale toroids (doughnut-shaped forms), made of both inorganic and organic materials.<\/span><\/p>\n

A number of forces can bring atoms and molecules together. These include surface tension, electrostatic attraction and repulsion, and a weak fundamental force known as van der Waals interactions. The toroids created by Khashab\u2019s team were formed via metal coordination. A metallic sodium chloride atom, an amphiphilic (both hydrophilic<\/a> and lipophilic<\/a>) molecule called saponin and a polymer known as chitosan<\/a> were combined and formed weak chemical bonds.<\/span><\/p>\n

\u201cThis is a result of what is known as coordination-driven self-assembly,\u201d explained Khashab. \u201cThe metal ions interact with different chemical motifs leading to the formation of novel frameworks and morphologies.\u201d<\/span><\/p>\n

Within just a few minutes, coordination bonding between the iron atoms and the oxygen and the hydrogen in the molecules initially drives the self-assembly of star-like nanostructures<\/a>. Repulsive electrostatic and hydrophobic interactions then lead to the formation of toroids.<\/span><\/p>\n

The toroids were approximately 3.9 to 4.8 micrometers in diameter and held their shape even a month after fabrication. Disassembly of the microstructures required five hours of mechanically stirring the solution.<\/span><\/p>\n

There are numerous naturally occurring biological structures that take a toroid shape; for example, proteins and DNA of some types of viruses and bacteria self-assemble in this way. Many of these are known to play an important role in the formation of pores in biomembranes<\/a>.<\/span><\/p>\n

This research could help to build a better understanding of how these complex biostructures are created and provide a way of mimicking them at the molecular level.<\/span><\/p>\n

\u201cNext, we hope to prepare a new generation of these hybrid structures with a temperature-responsive gap size,\u201d said Khashab. \u201cThese toroid structures could be used as pockets for active catalysis and separation.\u201d<\/span><\/p>\n","protected":false},"excerpt":{"rendered":"

Hybrid organic-inorganic materials can self-assemble into tiny doughnut-like structures. Engineered nanometer- and micrometer-scale structures have a vast array of uses in electronics, sensors and biomedical applications. Because these are difficult to fabricate, KAUST researchers are trying a bottom-up philosophy, which harnesses the natural forces between atoms and molecules such that microstructures form themselves. This approach, […]<\/p>\n","protected":false},"author":6,"featured_media":11310,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[17],"tags":[],"class_list":["post-11309","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-research"],"featured_image_urls":{"full":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2017\/01\/587830cf140ba093018b4569.jpg",500,350,false],"thumbnail":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2017\/01\/587830cf140ba093018b4569-150x150.jpg",150,150,true],"medium":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2017\/01\/587830cf140ba093018b4569-300x210.jpg",300,210,true],"medium_large":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2017\/01\/587830cf140ba093018b4569.jpg",500,350,false],"large":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2017\/01\/587830cf140ba093018b4569.jpg",500,350,false],"1536x1536":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2017\/01\/587830cf140ba093018b4569.jpg",500,350,false],"2048x2048":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2017\/01\/587830cf140ba093018b4569.jpg",500,350,false],"ultp_layout_landscape_large":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2017\/01\/587830cf140ba093018b4569.jpg",500,350,false],"ultp_layout_landscape":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2017\/01\/587830cf140ba093018b4569.jpg",500,350,false],"ultp_layout_portrait":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2017\/01\/587830cf140ba093018b4569.jpg",500,350,false],"ultp_layout_square":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2017\/01\/587830cf140ba093018b4569.jpg",500,350,false],"newspaper-x-single-post":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2017\/01\/587830cf140ba093018b4569.jpg",500,350,false],"newspaper-x-recent-post-big":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2017\/01\/587830cf140ba093018b4569.jpg",500,350,false],"newspaper-x-recent-post-list-image":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2017\/01\/587830cf140ba093018b4569.jpg",93,65,false],"web-stories-poster-portrait":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2017\/01\/587830cf140ba093018b4569.jpg",500,350,false],"web-stories-publisher-logo":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2017\/01\/587830cf140ba093018b4569.jpg",96,67,false],"web-stories-thumbnail":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2017\/01\/587830cf140ba093018b4569.jpg",150,105,false]},"author_info":{"info":["Amrita Tuladhar"]},"category_info":"Research<\/a>","tag_info":"Research","comment_count":"0","_links":{"self":[{"href":"https:\/\/www.revoscience.com\/en\/wp-json\/wp\/v2\/posts\/11309","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.revoscience.com\/en\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.revoscience.com\/en\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.revoscience.com\/en\/wp-json\/wp\/v2\/users\/6"}],"replies":[{"embeddable":true,"href":"https:\/\/www.revoscience.com\/en\/wp-json\/wp\/v2\/comments?post=11309"}],"version-history":[{"count":0,"href":"https:\/\/www.revoscience.com\/en\/wp-json\/wp\/v2\/posts\/11309\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.revoscience.com\/en\/wp-json\/wp\/v2\/media\/11310"}],"wp:attachment":[{"href":"https:\/\/www.revoscience.com\/en\/wp-json\/wp\/v2\/media?parent=11309"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.revoscience.com\/en\/wp-json\/wp\/v2\/categories?post=11309"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.revoscience.com\/en\/wp-json\/wp\/v2\/tags?post=11309"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}