{"id":3295,"date":"2011-06-30T21:14:56","date_gmt":"2011-06-30T21:14:56","guid":{"rendered":"https:\/\/mtlsites.mit.edu\/annual_reports\/2011\/?p=3295"},"modified":"2011-08-02T17:46:10","modified_gmt":"2011-08-02T17:46:10","slug":"formation-of-organic-molecular-nano-crystals-on-engineered-surfaces","status":"publish","type":"post","link":"https:\/\/mtlsites.mit.edu\/annual_reports\/2011\/formation-of-organic-molecular-nano-crystals-on-engineered-surfaces\/","title":{"rendered":"Formation of Organic Molecular Nano-crystals on Engineered Surfaces"},"content":{"rendered":"
Figure 1: (a) Optical microscope image (\u00d7150) of 1600 \u00b5m2 and (b) AFM image of 4 \u00b5m2 of the 500-nm patterned SAMs on the silicon substrate. The crystals dimensions are: (A) 250 \u00d7 220 \u00d7 74 nm3, (B) 230 \u00d7 205 \u00d7 70 nm3, (C) 180 \u00d7 160 \u00d7 57 nm3, and (D) 220 \u00d7 190 \u00d7 65 nm3. (c) Raman spectra of 100 individual glycine crystals found on the patterned SAMs. All crystals were determined to be \u03b2-form [1<\/a>] <\/sup>.<\/p><\/div>\n The formation of organic molecular nano-crystals is a topic of great interest in the pharmaceutical industry because of the potential increase in solubility of organic crystals below 1 micron and their potential use in nano-suspensions for direct injection. Direct production of nano-crystals through crystallization while controlling the crystal form (polymorph) is a difficult problem and a current active area of research. Investigators have explored methods based on the use of confinement (such as nano-wells), surface templating (such as polymers and self-assembled-monolayers (SAMs), and microfluidics [1<\/a>] <\/sup> [2<\/a>] <\/sup> [3<\/a>] <\/sup> [4<\/a>] <\/sup> [5<\/a>] <\/sup> [6<\/a>] <\/sup> [7<\/a>] <\/sup> [8<\/a>] <\/sup> [9<\/a>] <\/sup>. <\/sup>Our group has developed a method to \u201ccreate a confined volume\u201d for crystallization on templated surfaces (Figure 1), which results in both a confined volume and a templating effect [10<\/a>] <\/sup> [11<\/a>] <\/sup>.<\/p>\n In our research, we fabricate both hydrophilic and hydrophobic thiol SAMs on gold surfaces. With the use of photolithography or electron beam lithography, desired patterns of hydrophilic and hydrophobic SAMs can be generated, allowing the formation of small droplets of solution on the hydrophilic surfaces.\u00a0 By controlling the solution conditions through cooling evaporation or vapor diffusion of an anti-solvent, we can control the supersaturation profile and thus induce nucleation and growth of crystalline solids.<\/p>\n Our current work employs patterns of SAMs allowing the formation of droplets as small as 100 nm in diameter. Using these droplets, we are probing issues related to nucleation and polymorphism in a number of different systems to better understand the fundamentals of nucleation and polymorphism.<\/p>\n<\/div> The formation of organic molecular nano-crystals is a topic of great interest in the pharmaceutical industry because of the potential…<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":[],"categories":[6083],"tags":[6229,6230],"_links":{"self":[{"href":"https:\/\/mtlsites.mit.edu\/annual_reports\/2011\/wp-json\/wp\/v2\/posts\/3295"}],"collection":[{"href":"https:\/\/mtlsites.mit.edu\/annual_reports\/2011\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/mtlsites.mit.edu\/annual_reports\/2011\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/mtlsites.mit.edu\/annual_reports\/2011\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/mtlsites.mit.edu\/annual_reports\/2011\/wp-json\/wp\/v2\/comments?post=3295"}],"version-history":[{"count":20,"href":"https:\/\/mtlsites.mit.edu\/annual_reports\/2011\/wp-json\/wp\/v2\/posts\/3295\/revisions"}],"predecessor-version":[{"id":4301,"href":"https:\/\/mtlsites.mit.edu\/annual_reports\/2011\/wp-json\/wp\/v2\/posts\/3295\/revisions\/4301"}],"wp:attachment":[{"href":"https:\/\/mtlsites.mit.edu\/annual_reports\/2011\/wp-json\/wp\/v2\/media?parent=3295"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/mtlsites.mit.edu\/annual_reports\/2011\/wp-json\/wp\/v2\/categories?post=3295"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/mtlsites.mit.edu\/annual_reports\/2011\/wp-json\/wp\/v2\/tags?post=3295"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}