**Author details**

*Renewable and Sustainable Composites*

when exposed to UV light.

even at the highest TiO2 content, i.e., 1.5% wt.

came from biocomposites containing 1.5% wt TiO2.

dation of the bond at 3000 cm<sup>−</sup><sup>1</sup>

applications.

**Acknowledgements**

completion of this research.

The authors declare no conflict of interest.

**Notes/thanks/other declarations**

**Conflict of interest**

such anatase structure.

biocompatibility and nontoxicity. Through a straightforward technique, TiO2 nanoparticles dispersed onto a chitosan matrix permitted formulating a renewable and biodegradable composite film capable of excellent antibacterial properties

The synthesis process used did not affect the crystal structure of the dioxide, which remains anatase polymorph. X-ray diffraction characterization confirmed

Chitosan demonstrated to be a very good selection as a matrix able to hold in place the TiO2 nanoparticles. Incorporation of TiO2 nanoparticles onto the chitosan film via solution casting method produced the chitosan/TiO2 biocomposite films. The immobilized TiO2 exhibited good distribution in the chitosan film, as demonstrated via secondary electron microscopy. From those observations, one can infer that chitosan provides an excellent substrate to immobilize TiO2 nanoparticles. Electron microscopy also demonstrated that the nanostructured TiO2 particles dispersed homogeneously within the polymer matrix without obvious aggregation

Under UV light, TiO2 proved effective against *E. coli* and *S. aureus*. This is due to the generation of ROS from the UV excitement of the TiO2. The growth curve analysis demonstrated that the growth rate of bacteria was affected, as evidenced by the Kirby-Bauer technique. In the present experimental conditions, the best effect

The irradiation with UV light affected the chitosan covalent bonds, as revealed

(C▬H) demonstrated that extensive UV light

by the Fourier-transform infrared spectroscopy. From the spectra of chitosan with TiO2, one could infer that more oxygen molecules were present. The degra-

irradiation is detrimental to the biopolymer, compromising its integrity in actual

The research presented for the synthesis of the films is an effective way to immobilize TiO2 while retaining the structure of the stronger photocatalytic polymorph.

This material is based upon work supported by the National Science Foundation under grants No. 0851449 and 1345156 (CREST Program). The authors would like to thank Ms. Barbara Sanchez along with the UPRM Biology Department for the use of their facilities. Professor Matias Cafaro provided insightful comments for the

Most of the work completed in the laboratory was with the assistance of the following undergraduate students: Amanda Quintero, Yamalis Lopez, Christian McRobert, Katyria Torres, Kenneth Serrano, Karimar Amador, Ariana Torres, Luis

Orta, Genesis Reyes, Luis Olmo, Karla Romero, and Edwin Ramos.

**90**

Johnny López Calero, Zuleika Oquendo Berríos and Oscar M. Suarez\* University of Puerto Rico at Mayagüez, Mayagüez, Puerto Rico

\*Address all correspondence to: oscarmarcelo.suarez@upr.edu

© 2019 The Author(s). Licensee IntechOpen. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/ by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
