Addition of Titanium Dioxide and Sources Effects on UV

Transmittance and Hydrophilicity of Chitosan Film

Kuo-feng Chou 1

and Li-wen Wang 1

1 Department of Biomedical Engineering, Yuanpei University, No.306, Yuanpei St., HsinChu, Taiwan 30015

Abstract. A hybrid membrane of chitosan and titanium dioxide (TiO2) was formed for the purpose of

protecting skin. Chitosan extracted from shrimp shells mixed with 0~4wt% TiO2 particles by sol-gel hybrid

method. The hybrid was coated on glass slide for the photo spectrum analysis and hydrophilicity testing.

Transmittance of Ultraviolet (UV)-Visible light (230nm~800nm) of the hybrid was determined by a UV-

Visible photo spectrum. The hydrophilicity of hybrid was measured by contact angle method. The sample

contained 1wt% has best UV absorption capability. For the sample with high TiO2 concentration, the

dispersion of TiO2 is low and particle size is large so that the absorption of UVB becomes weak. On the other

hand, the effect of the concentration of chitosan on the transmittance of UV is not significant. The

hydrophilicity of hybrid could be improved by raising the concentration of chitosan. The hybrid could be

applied into the dressing material which could block UV radiation.

Keywords: Chitosan, sol-gel, titanium dioxide

1. Introduction

Recent years, the ozone layer by human emissions of pollutants constantly being destroyed, exposure to

ground UV intensity gradually increased, excessive exposure can also have a negative impact on human skin,

eyes and other organs and immune system [1], [2]. Appropriate choice of materials and the development of a

can block ultraviolet radiation is a very important thing, can be used in any place, such as glasses or windows,

or can be used in medicine. The method of treatment of cancer, one of the main methods of radiation through

a chemical treatment or a chemical treatment method, most of the chemical agent or radiation therapy is to

kill rapidly proliferating cells, through to achieve the purpose of treatment, but at the same time likely to kill

rapidly proliferating in vivo normal cells, resulting in a considerable number of side effects, including nausea,

vomiting, diarrhea, neutropenia, oral ulcers, burning, numbness and other symptoms, but often because of

radiation and chemotherapy to radiation dermatitis caused by local organizations. Main selections of

materials are titanium dioxide and chitosan. Titanium dioxide is regarded as a good anti-radiation additive

can be incorporated into the polymer to form anti-radiation dressing. In the past few decades, there are three

different titanium dioxide polymorphs: rutile (RE), anatase (A), and brookite, and their electrical, magnetic,

catalytic and electrochemical properties have been widely studied [3]-[6]. A- photocatalytic titanium oxide is

suitable for the application, R- titanium oxide having a high refractive index and hiding power, and good

chemical stability and resistance to UV shielding effect [7]. Chitosan is a chitin isolated from crustacean

shell out a lot of natural polymers obtained by deacetylation, which has biocompatibility, biodegradability

and biological activity of the properties can be applied in different fields such as food, medicine,

biomedicine, pharmacology, biotechnology, biomaterials, drugs and cosmetics [8]-[11].

2. Methods

2.1. Materials Corresponding author. Tel.: + 886-3-610-2345; fax: +886-3-610-2347.

E-mail address: kuofeng@mail.ypu.edu.tw.

2015 5th International Conference on Biomedical Engineering and Technology (ICBET 2015)

IPCBEE vol.81 (2015) © (2015) IACSIT Press, Singapore

DOI: 10.7763/IPCBEE. 2015. V81. 5

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Chitosan-A (from shrimp shells, ≧75% deacetylated), Chitosan-B (from white mushroom, high purity,

Mv 60,000-120,000), Titanium(lv) oxide (minimum 99.0%, FW=79.88) were purchased from Sigma-Aldrich

co., ltd. Hydrogen Peroxide (35%, M=34.02) was purchased from Astamuse company, ltd. Acetic Acid (95%

(w/w)) was purchased from Ehco Chemical co., ltd. Penetration analysis spectrometer (USB4000, 200nm ~

800nm) was purchased from Ocean Optics. Rotation of the brushless motor coater (W380*D470*H300) was

purchased from Pentad Scientific Co., ltd. Element image measuring system (XC432VR, 40x~1000x, 1/3”)

was purchased from Tunry Technology Industry Corporation. Electronic scales (Precisa PL202-S mettler)

was purchased from Chuan Hua Co., ltd. Hot Plates (Cimarec SP131325) was purchased from Thermo

Fisher Scientific Inc.

2.2. Experiments

Chitosan were uniformly mixed with 3% acetic acid and water to form the solutions of 0%, 1.5%, 2%,

2.5% and 3%, respectively. 2% TiO2 powder is poured into the solution and stirring for 5 minutes, next shake

by an ultrasonic oscillator for 40 minutes. In addition, the chitosan extracted from white mushroom also were

made into solution of 1%, 1.5%, 2%, 2.5% and 3%.

For the preparation of chitosan coating, a glass slide washed with H2O2 solution in a ultrasonic

oscillators for 30 minutes at 80 C. The chitosan solution was spin coated unto the washed glass slide with

3000 ~ 4000rpm for 10 seconds and 500 ~ 1000rpm for 20 seconds.

The UV-Vis transmittance of chitosan films were measured by a UV-Vis spectrometer obtained from

Ocean Optical co., and the measure range is 240nm~800nm.

The hydrophilicity of the sample is determined by the contact angle on the interface between chitosan

film and water droplet measured with a home-made machine and image capture system.

Fig. 1: TiO2/Chitosan membrane, TiO2 content: (a) 0% (b) 1% (c) 2%

300 400 500 600 700 8000

20

40

60

80

100

T (

%)

wavelength(nm)

TiO2(%)

0

1

2

3

4

Fig. 2: UV-Vis spectra of chitosan membranes contain TiO2.

3. Results and Discussion

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3.1. Effect of Addition of Titanium Dioxide

The chitosan film added 0 ~ 2wt% of titanium dioxide is obtained by microscope as shown in Fig. 1.

There are clearly visible changes on the morphology of films between the presence and absence of titanium

dioxide. The distribution of TiO2 is more uniform in the sample of 1wt% than that of 2wt%. In addition, UV-

Vis spectra of chitosan membranes contain 0 ~ 2wt% of TiO2 is shown in Fig. 2. The film contained titanium

dioxide presents that the ultraviolet shielding ability is good, but there was no obvious change in the

concentration differences. The results indicate that a low concentration of the titanium dioxide can have a

good UV shielding ability, and save costs. The transmittance of all sample contained TiO2 are low.

3.2. Effect of Concentration of Chitosan

UV-Vis spectra of chitosan membranes with different concentrations are shown as Fig. 3. Different

concentrations showed no significant differences. The mixed solution of 3% concentration may be saturated,

such that the decreasing UV resistance. The UV absorbance of chitosan is not as high as that of TiO2.

Contact angle of chitosan membranes with different concentrations and TiO2 contents is shown in Fig. 4. The

hydrophilicity of chitosan film linearly decreases with the increase of concentration, but if TiO2 was added,

hydrophilicity would be raised.

300 400 500 600 700 8000

20

40

60

80

100

T(%

)

wavelength(nm)

Chi(%)

1.0

1.5

2.0

2.5

3.0

Fig. 3: UV-Vis spectra of chitosan membranes with different concentrations.

0.0 0.5 1.0 1.5 2.0 2.5 3.025

30

35

40

45

50

55

60

65

TiO22%

TiO20%

Co

nta

ct A

ng

le

Chi content (wt%)

Fig. 4: Contact angle of chitosan membranes with different concentrations and TiO2 contents.

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3.3. Effect of Source

The both spectrum of chitosan films extract from shrimp and mushroom are plotted in Fig. 5. The

transmittance of mushroom chitosan film for UVA-UVB (300nm-250nm) is lower than that of shrimp

chitosan film. This result implies the capacity of UV resistance of chitosan extract from mushroom UV is

better than that of shrimp chitosan. The effect of source also could find in the result of contact angle

measurement as shown in Fig. 6. The relation between contact angle and the concentration of chitosan

solution is almost liner for the shrimp chitosan film, but the contact angle is constant for high concentration

chitosan film. It seems that a structure difference between the shrimp and mushroom chitosan, the

speculation should be confirmed in the future.

300 400 500 600 700 8000

20

40

60

80

100

T(%

)

wavelength(nm)

Chi0%

Chi1%-mushroom

Chi1%-shrimp

Fig. 5: UV-Vis spectra of chitosan membranes made from different sources

0.0 0.5 1.0 1.5 2.0 2.5 3.025

30

35

40

45

50

55

60

65

Co

nta

ct a

ng

le

Chi content(wt%)

Shrimp

mushroom

Fig. 6: Contact angle of chitosan membranes made from different sources

4. Conclusion

The transmittance and hydrophilicity of chitosan film had been measured and the effects of TiO2 and

source were discussion. The addition of TiO2 or high concentration would also reduce the transmittance of

chitosan to UV and Visible light, and the UV resistance of chitosan extracted from mushroom is higher than

that of chitosan extracted from shrimp. On the other hand, the hydrophilicity of chitosan film decreases with

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the increase of concentration. However, the trend would be stopped at high chitosan concentration as the

addition of TiO2 or for the mushroom source.

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[3] S.D. Mo, W.Y. Ching. Electronic and optical properties of three phases of titanium dioxide: rutile, anatase, and

brookite. Physical Review B. 1995; 51 (19): 13023-13032.

[4] A. Fujishima, K. Honda. Electrochemical photolysis of water at a semiconductor electrode. Nature. 1972, 238 (58):

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