University of California

University of South Florida

Vinay K Gupta

Nicholas Lawrence Abbott

Justin J Skaife

Timothy B Dubrovsky

Rahul Shah

Cecil Coutinho

Ashok Kumar

Subrahmanya Mudhivarthi

Maya Trotz

Organic-inorganic composites were prepared as colloidal particles of a cross-linked, thermally responsive polymer. Hybrid PNIPAM-polysiloxane particles and composite polymeric particles with embedded nanoparticles of an inorganic metal-oxide (MO) such as CeO2 and TiO2 were formed. To promote the incorporation of unaggregated nanoparticles, temperature responsive microspherical gels (microgels) of N-isopropylacrylamide (NIPAM) with interpenetrating (IP) linear chains of poly(acrylic acid) (PAA) were used. The organic-inorganic composition of the hybrid polymer network was controlled by changing the time for condensation and hydrolysis of the siloxane monomer during synthesis. Experimental results indicated that the planarization of silicon oxide wafers using these hybrid particles and composites exhibited lower topographical variations and surface roughness as compared to slurries consisting of only silica or ceria nanoparticles while achieving similar removal rates and better or similar frictional characteristics.

Polymeric microgels for chemical mechanical planarization (CMP) processing

Interactions between molecules that are components of self-assembled monolayers and other molecules can be amplified and transduced into an optical signal through the use of a mesogenic layer. The invention provides for a method for detecting an analyte, comprising contacting with said analyte a recognition moiety for said analyte, wherein said contacting causes at least a portion of a plurality of mesogens proximate to said recognition moiety to detectably switch from a first orientation to a second orientation upon contacting said analyte with said recognition moiety; and detecting said second orientation of said at least a portion of said plurality of mesogens, whereby said analyte is detected.

Optical amplification of molecular interactions using liquid crystals

Microcomposites comprising titanium dioxide (TiO2) nanoparticles embedded within cross-linked, thermally responsive microgels of poly(N-isopropylacrylamide) are disclosed. Interpenetrating linear chains of poly(acrylic acid) functionalize the nanoparticles for dispersal within the microgel framework. The microcomposites show rapid sedimentation, which is useful for gravity separation applications such as environmental remediation via photocatalytic degradation. The extent of loading of the TiO2 within the colloidal particles can be easily manipulated from 10% (weight) to a value as high as 75%. The microgel-titania composites showed rapid sedimentation, which is useful for gravity separation of these particles in photocatalytic applications. The settling of the microgel-titania composites occurred over minutes and was much faster than solid, impermeable spheres. As the content of TiO2 increased within the particles from 10% to 75%, the increased effective particle density led to significant decrease in the settling time from approximately 2200 seconds to approximately 100 seconds.

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Interactions between molecules which are components of self-assembled monolayers and other molecules can be amplified and transduced into an optical signal through the use of a mesogenic layer. The invention provides a device and methods for detecting analytes. The device comprises a substrate onto which a self-assembled monolayer is attached and a mesogenic layer which is anchored by the self-assembled monolayer. The mesogenic layer undergoes a change in conformation in response to the molecular interaction.

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Urbana, IL, United States of America

Vinay K Gupta