Date of Award

Spring 5-20-2019

Document Type

Thesis

Degree Name

Master of Science (MS)

Department

Chemistry

First Advisor

Xiu R. Bu, Ph.D.

Second Advisor

John H. Hall,Ph.D.

Third Advisor

Myron N. V. Williams, Ph.D.

Abstract

The objective of this research was to study the adsorption and photodegradation of crystal violet (CV) dye by using poly(2-hydroxyethylmethacrylate) (PHEMA) hydrogel and nanocomposite TiO2-PHEMA hydrogel. Since the TiO2 nanoparticle has poor solubility, another goal of this study was to make a uniform TiO2 nanocomposite gel. These gels can be used in water treatment and can be easily photodegrade by exposure of sunlight which is similar to exposing to UV-vis. PHEMA was synthesized by free radical polymerization. The nanocomposite gels were characterized by FT-IR and XRD to confirm the presence of TiO2 nanoparticles and CV dye inside the PHEMA hydrogel. The XRD data showed that not only maintaining the crystallinity of the three different phases that had been used, but also the uptake of the dye inside the nanocomposite gels. Moreover, the FT-IR demonstrated the presence of the functional groups of the chemical structure of the gel as well as the nanocomposite gels with the CV dye. The adsorption of CV dye was examined through monitoring UV-Vis absorption. The kinetic study indicated the adsorption of the dye by the nanocomposite gels until reached equilibrium, which is the zero concentration. The photodegradation of CV dye was examined using a medium pressure Hg lamp. It was determined that the composite gels adsorb CV dye from the solution at the beginning while under the photochemical condition. Eventually, the dye in the gel was photodegraded, indicating that in the gel system, the photodegradation process is still effective to dyes. The composite gels containing pure anatase phase titanium are much better photocatalysts and took less time of adsorption than those containing pure rutile and anatase/rutile mixed phases of titania.

Share

COinS