Recommended Results

Rheology of Lyotropic Nanomaterial Liquid Crystals

Description:

Processing of lyotropic nanomaterial dispersions is increasingly recognized as a scalable route for producing large ordered assemblies of anisotropic nanomaterials. Achieving controlled alignment in solid materials produced from dispersions requires understanding the dispersions’ rheological properties. It is well established that lyotropic dispersions of rod-like polymers typically have the following rheological signatures: a maximum in the viscosity versus concentration curve, long oscillatory transients, three region viscosity versus shear rate behavior, and a first normal stress difference that goes from positive to negative and back to positive with increasing shear rate. Since rheological properties are largely governed by shape, lyotropic dispersions of rod-like nanomaterials can also be expected to have some of these features. On the other hand, the range of possible nanomaterials sizes, polydispersities, attractive interactions, and densities suggests a broader possible variation in rheological properties between systems. This work reports the rheological commonalities and distinctions between several lyotropic nanocylinder dispersions namely, carbon nanotubes, inorganic nanorods, inorganic nanowires, and cellulose nanocrystals. Increased understanding of the reasons for the similarities and differences between these and other systems is not only scientifically important, it will also aide in developing a framework for lyotropic nanomaterial rheology that can help guide the development of effective processing schemes. 

Date: 2017-08-29, 11:30 - 12:30
Language: English
Trainer: Dr. Virginia Davis

Dr. Davis earned her Ph.D. from Rice University in 2006 under the guidance of Professor Matteo Pasquali and the late Nobel Laureate Richard E. Smalley. Prior to attending Rice, Dr. Davis worked for eleven years in Shell Chemicals' polymer businesses in the US and Europe. Her industrial assignments included manufacturing, technical service, research, and global marketing management.All of these assignments were focused on enabling new polymer formulations to become useful consumer products. 

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Hayley Gilbert
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