Transcript

Nanoscale Films:bounded by two transitions:

dryingdrying and wettingwetting

CAREER: Nanoscale Surficial Disordered Films: Multilayer Adsorbates CAREER: Nanoscale Surficial Disordered Films: Multilayer Adsorbates in Oxide Ceramics,in Oxide Ceramics, PI: Jian Luo, Clemson University, DMR-0448879

Pressure-balance and diffuse-interface models have been developed for surficial films on oxides, predicting the universal existence of three adsorption/wetting regimes with increasing T:

• "Dry" = Langmuir submonolayer adsorption,• "Moist" or “prewetting” = stable nanoscale

surficial films or multilayer adsorbates, and• "Wet" = perfect wetting liquid films with

arbitrary thickness.This CAREER project focuses on experimental and modeling studies of surficial films on oxide materials; meanwhile, our collaborators at MIT (Chiang, Carter, et al.), LBNL (Cannon) and other institutes have investigated analogous interfacial phenomena for two other configurations: native oxide films on Si and intergranular films in Si3N4. All together, a new and unified model is envisioned.

Additionally, recent hot-stage wetting experiments of Bi2O3 on ZnO {11-20} surfaces showed an interesting “cross-over” in contact angle versus temperature, suggesting a mechanistic change in the adsorption or spreading behaviors.

TTwettingwetting:

0h +

TTdryingdrying:

h 0

High-Resolution TEM Image

Education and Outreach,Education and Outreach, PI: Jian Luo, Clemson university, DMR-0448879

Two Websites have been developed and will be updated during the 5-year project period• Education Website: "A Series of Open Mini-Courses in Materials Science and Engineering" http://

people.clemson.edu/~jianluo/education/• Research Results Dissemination Website: "Digital Archive: Nanoscale Surficial Amorphous Films in

Oxide Materials“ http://people.clemson.edu/~jianluo/Research/SF.html

Three (3) high school juniors/seniors and two (2) incoming Clemson freshmen participated in 2-5 weeks’ summer research on this CAREER project. These students were mentored by graduate students Qian and Arcot together with the PI. These activities have been conducted in conjunction with Clemson’s J. E. Sirrine and EUREKA! programs, which offered some logistic support.

Education WebsiteEducation WebsiteHigh school students presented their High school students presented their

summer research results summer research results


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