281223 Shear Free and Blotless Cryo-TEM Imaging: A New Method for Probing Early Evolution of Nanostructures

Tuesday, October 30, 2012: 10:15 AM
414 (Convention Center )
Jinkee Lee1, Amitesh Saha2, Jens Rieger3, Arijit Bose2 and Anubhav Tripathi4, (1)School of Mechanical Engineering, Sungkyunkwan University, Suwon, South Korea, (2)Department of Chemical Engineering, University of Rhode Island, Kingston, RI, (3)BASF, Ludwigshafen, Germany, (4)School of Engineering, Brown University, Providence, RI

Cryogenic transmission electron microscopy (cryo-TEM) is a powerful method to image native state morphologies of nanoscale soft and hard objects suspended in solvents.  Sample preparation is a critical step towards producing images at length and time scales of interest. We demonstrate a nearly shear-free sample thinning method which simultaneously allows imaging of evolving nanostructures at sub-second time scales. This device breaks the trade-off between high shear and short time scales typical in current cryo-TEM sample preparation methods. We demonstrate the low-shear feature of the new method by imaging worm-like micelles, showing an interconnected network, in contrast to the traditional sample preparation method which shows aligned micelles at similar time points.  The time resolution of this method is demonstrated by imaging morphologies of calcium carbonate (formed through the reaction of calcium chloride with sodium carbonate) at sub-second time scales, capturing its evolution from an amorphous to a crystalline state.  The impact of hyperbranched polyglycerol additives on the amorphous to crystalline transition in calcium carbonate at short times is examined. Early images at low shear provide unique fundamental insights into mechanisms of nanostructure evolution, thus offering a new paradigm for research in materials sciences, soft matter and biological sciences.

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See more of this Session: Fundamentals of Interfacial Phenomena I
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