CRĀSI News

Monday, August 27, 2018

The Odyssey of the Mind team met to brainstorm new ideas and discuss current technical challenges. 

Monday, July 23, 2018

The Odyssey of the Mind team met to brainstorm new ideas and discuss current technical challenges. 

Monday, June 18, 2018

The Odyssey of the Mind team met to brainstorm new ideas and discuss current technical challenges. 

Monday, May 14, 2018

The Workshop on Topological Protection in Messy Matter, sponsored by Georgia Tech's Community for Research on Active Surfaces and Interfaces (CRĀSI) will be held in rooms 1116-1118 of the Marcus Nanotechnology Building (map) on the Georgia Tech campus on May 14-15, 2018. The workshop will bring together distinguished researchers from diverse intellectual communities to present and moreover to develop new ways of exploiting topology in "messy" systems, including but not limited to disordered, fluid, amorphous, active, structured and quasicrystalline systems.

Friday, May 11, 2018

"What topology reveals about real systems" a tutorial intended to introduce topology with a minimum of math and provide  a background as to how it applies to real systems such as those considered in the workshop, will be held at 10AM in Marcus Nano 1116-1118 on the Friday before the workshop. All are welcome at the tutorial.

Monday, May 7, 2018

The Odyssey of the Mind team met to brainstorm new ideas and discuss current technical challenges. 

Thursday, April 26, 2018

A cell can be conceived as a factory containing a hierarchical network of nanomachines. Most of these nanomachines undergo motions that are essential to their functions. Understanding the characteristic translational and rotational motions, as well as their coupling, is crucial to understand the working mechanism of these nanomachines and the related cellular processes. However, the knowledge of rotational dynamics in and on live cells remains highly limited due to technical limitations. We have developed the Single Particle Orientation and Rotational Tracking (SPORT) techniques to offer high spatial, angular, and temporal resolutions simultaneously for visualizing characteristic rotational dynamics (e.g., rotational rate, mode, and direction) of anisotropic plasmonic gold nanorods in living cells. SPORT enables us to acquire the characteristic rotational dynamics involved in cellular processes, such as adhesion, endocytosis, and transport of functionalized nanoparticles, as may be relevant to drug delivery and viral entry. It also provides a significant new dimensionality to the computational efforts in biology. Distinctive rotational behaviors, including rotational rate and mode, can be correlated with chemical and physical properties and biological functions of surface modifiers.

Wednesday, April 25, 2018

Colloidal quantum dots (QDs) have many advantages of heterogeneous and homogeneous photocatalysts for reactions relevant to energy conversion and organic synthesis. This talk focuses on how the surface chemistry of the particle can be tuned to promote selectivity for certain reaction pathways, enantioselectivity of products, and the formation of colloidally stable assemblies for energy and charge funneling, for reactions such as proton and CO2 reduction, and carbon-carbon coupling. Quantitative characterization of the pKa’s of groups within angstroms of the QD surface, using shifts in optical spectra of the QDs, will also be discussed.  

Monday, April 9, 2018

Microfluidic techniques enable exquisite control over the physical and chemical properties of experimental systems.  We will describe techniques we have developed to sculpt chemical environments in space and time, and interferometric methods to visualize these concentration fields as they evolve.  We will illustrate with direct, dynamic measurements of water sorping into ionic liquids, reagent depletion during interfacial polymerization reactions, and solvent diffusion through hydrogels.

 

We then use this solution-sculpting to study the diffusiophoretic migration of colloids under imposed chemical gradients.  Such phenomena occur quite generally in response to non-equilibrium chemical fluxes, and therefore arise in a wide variety of real-world systems.  Nonetheless, diffusiophoresis has remained stubbornly difficult to observe or characterize directly.  We will discuss the physico-chemical phenomena that underlie diffusiophoresis, and therefore how to intuitively design systems with desired diffusiophoretic properties.  

 

Finally, we will build on this foundation to introduce conceptually new colloidal interactions that are non-equilibrium but long-lived, much longer-ranged than is possible in aqueous suspensions, and are chemically-specific.  We envision a broad role for such interactions in destabilizing suspensions, breaking emulsions, and extracting compounds.

Monday, March 26, 2018

The Odyssey of the Mind team met to brainstorm new ideas and discuss current technical challenges. 

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