Tuning dispersion and optical property of ZnO quantum dots in polymers through exfoliated nanoplatelets

COLL 335

Dazhi Sun, sundz@tamu.edu, Department of Mechanical Engineering, Texas A&M University, 3123-TAMU, college station, TX 77843 and Hung-Jue Sue, hjsue@tamu.edu, Polymer Technology Center, Department of Mechanical Engineering, Texas A&M University, 3123 TAMU, College Station, TX 77843-3123.
The dispersion state of colloidal zinc oxide (ZnO) quantum dots (QDs) in polymer is found to be tunable via the addition of exfoliated nanoplatelets. Without the presence of nanoplatelets, the QDs without organic capping agents form large aggregates. The dispersion state can be tuned from micro-scaled to nano-scaled aggregates, and to individually dispersed QDs in polymer by simply adjusting the weight ratio between QDs and exfoliated nanoplatelets. It is found that exfoliated nanoplatelets are more effective in the dispersion of QDs than stacked nanoplatelets. Furthermore, surface charge characteristics, geometry, and aspect ratio of nanoplatelets play an important role in the dispersion of QDs. The polymer hybrid nanocomposites that contain well-dispersed QDs and exfoliated nanoplatelets are highly transparent and show UV-absorption property. The optical absorption and photoluminescence of ZnO QDs in polymers vary with different QD dispersion states. The mechanisms of optical property of ZnO QDs in polymers are also discussed.

Keywords: quantum dots, polymer nanocomposites, dispersion, nanoplatelets, optical property.

 

Polymer-Nanoparticle Systems: Theory, Simulation, Experiments
2:00 PM-5:00 PM, Tuesday, April 8, 2008 Morial Convention Center -- Rm. 227, Oral

Division of Colloid & Surface Chemistry

The 235th ACS National Meeting, New Orleans, LA, April 6-10, 2008