PHOTO-DEGRADATION ANALYSIS OF COTTON WOVEN FABRIC
PHOTO-DEGRADATION ANALYSIS OF COTTON WOVEN FABRIC MODIFICADED BY TiO2 AND FILM DLC D.O. Freitas Furtado1, F.M.F. Galvão2, J.H.O. Nascimento3, Santos, L.V4, C.Alves Júnior5. 1 Mechanical Engineering Post graduation, Department of Mechanical Engineering, UFRN, Campus Universitário, Lagoa Nova, 59072-970, Natal, RN, Brazil. 2,3 Department of Textile Engineering, UFRN, Natal, RN, Brazil 4 UNIVAP/Instituto de Pesquisa e Desenvolvimento, São José dos Campos, SP, Brazil. 5 Universidade Federal Rural do Semiárido, UFERSA, Mossoró, RN, Brazil. e-mail: [email protected] Degradation of methylene blue dye on the surface of 100% cotton woven fabric modified by TiO2 particles and DLC film (Diamond-Like Carbon) are described in this work. The TiO2 particles were diluted in distilled water and deposited in the fabric samples by sprinkling. Then the samples are submitted to the process for PECVD deposition of DLC film 600,1200 and 1800s. The characterization of the modification was performed by scanning (SEM) electron microscopy. Portable Spectrophotometer was used to evaluate the degradation of the dye before and after exposure to UV irradiation for 7200s. The results showed high degradation with spectra that show variation in the value of K / S (K = molar absorption coefficient, S = dispersion coefficient) between before and after irradiation of up to 115.99% in the first 900seconds.
Keywords: Photodegradation. TiO2. Plasma. Cotton. Fabric.Spectrofotometria. Introduction The incorporation of nanomaterials in textile finishing is a new concept that has been introduced in recent years. Several new properties acquired with the textile surface modification, among them is the self-cleaning. Among the most commonly nanomaterials used for this purpose is titanium dioxide (TiO2). It presents features of high photocatalytic active, high stability, non toxic and low relative cost [1]. In this work is proposed a new technique for deposition of TiO2 by sprinkling using nebulizer and after DLC Film deposition by plasma on cotton woven fabric. Experimental part Cotton woven fabric samples were cut into 0,1m. Air-jet pneumatic nebulizer was used to sprinkle a solution of TiO2, 0,029g, in water, 10ml. It was sprinkled until the solution be fully consumed. Then, samples were taken to dry in a Klin for 300s at a temperature 100ºC. They are taken to the plasma reactor for deposition of DLC film in three different time: 600, 1200 and 1800s; 20 cm3/s CH4, 0,05 torr, 450V. Photo degradation analysis was performed in a cabin color assessment, submitting the samples to blue
methylene dye, then, to UV light radiation by 7200s. Surface morphology was characterized by scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS). Results and discussion Images of modified sample surface showed grain-shaped elements (Figure 1a). EDS analysis identified titanium in the composition of this elements (Figure 1b). Photodegradation graphics have shown that samples with TiO2 and DLC film deposited for 600s have greater degradation kinetic after UV irradiation. To this time, the K/S variation is 115.99% in the first 900s at a wavelength 665nm (blue methylene dye) (Figure 1c). 120
Padrão MCSTiO2
TiO2DLC600s
220
MCTiO2
200
900s 3600s 7200s
100
900s 3600s 7200s
180 160
80
K/S
K/S
140 60
120 100
40
80 60
20
a
40 20
0 400
450
500
550
600
650
700
400
450
500
550
600
650
700
Comprimento de onda (nm)
Comprimento de onda (nm) 200 200
TiO2DLC1800s
TiO2DLC1200s
180
MCTiO2
160
900s 3600s 7200s
MCTiO2 900s 3600s 7200s
180 160 140
140 120
K/S
K/S
120 100
80
80
60
60
40
40
b
20
100
c 400
20 450
500
550
600
Comprimento de onda(nm)
650
700
400
450
500
550
600
650
700
Comprimento de onda (nm)
Fig.1 – Modified fabric samples with TiO2 and DLC film. (a) MEV, (b) EDS, (c) Photodegradation by UV irradiation. Conclusions
TiO2 sprinkling and DLC film deposition by plasma on cotton woven fabric was effective. The sample topography showed modification after the deposition and the photodegradation occurred in all samples when compared with the sample without deposition. Between the times of DLC film deposition, 600s demonstrated better kinetics of degradation of the dye on the fabric. This technique does not use toxic solutions and reduces the amount of water used in the process References [1] Tung, W.S., Daoud, W.A., Photocatalytic self-cleaning keratins: A feasilibility study, Acta Biomaterialia, 5, 50-56, 2009. Acknowledgement: CAPES, CNPq
Keywords: Photodegradation. TiO2. Plasma. Cotton. Fabric.Spectrofotometria. Introduction The incorporation of nanomaterials in textile finishing is a new concept that has been introduced in recent years. Several new properties acquired with the textile surface modification, among them is the self-cleaning. Among the most commonly nanomaterials used for this purpose is titanium dioxide (TiO2). It presents features of high photocatalytic active, high stability, non toxic and low relative cost [1]. In this work is proposed a new technique for deposition of TiO2 by sprinkling using nebulizer and after DLC Film deposition by plasma on cotton woven fabric. Experimental part Cotton woven fabric samples were cut into 0,1m. Air-jet pneumatic nebulizer was used to sprinkle a solution of TiO2, 0,029g, in water, 10ml. It was sprinkled until the solution be fully consumed. Then, samples were taken to dry in a Klin for 300s at a temperature 100ºC. They are taken to the plasma reactor for deposition of DLC film in three different time: 600, 1200 and 1800s; 20 cm3/s CH4, 0,05 torr, 450V. Photo degradation analysis was performed in a cabin color assessment, submitting the samples to blue
methylene dye, then, to UV light radiation by 7200s. Surface morphology was characterized by scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS). Results and discussion Images of modified sample surface showed grain-shaped elements (Figure 1a). EDS analysis identified titanium in the composition of this elements (Figure 1b). Photodegradation graphics have shown that samples with TiO2 and DLC film deposited for 600s have greater degradation kinetic after UV irradiation. To this time, the K/S variation is 115.99% in the first 900s at a wavelength 665nm (blue methylene dye) (Figure 1c). 120
Padrão MCSTiO2
TiO2DLC600s
220
MCTiO2
200
900s 3600s 7200s
100
900s 3600s 7200s
180 160
80
K/S
K/S
140 60
120 100
40
80 60
20
a
40 20
0 400
450
500
550
600
650
700
400
450
500
550
600
650
700
Comprimento de onda (nm)
Comprimento de onda (nm) 200 200
TiO2DLC1800s
TiO2DLC1200s
180
MCTiO2
160
900s 3600s 7200s
MCTiO2 900s 3600s 7200s
180 160 140
140 120
K/S
K/S
120 100
80
80
60
60
40
40
b
20
100
c 400
20 450
500
550
600
Comprimento de onda(nm)
650
700
400
450
500
550
600
650
700
Comprimento de onda (nm)
Fig.1 – Modified fabric samples with TiO2 and DLC film. (a) MEV, (b) EDS, (c) Photodegradation by UV irradiation. Conclusions
TiO2 sprinkling and DLC film deposition by plasma on cotton woven fabric was effective. The sample topography showed modification after the deposition and the photodegradation occurred in all samples when compared with the sample without deposition. Between the times of DLC film deposition, 600s demonstrated better kinetics of degradation of the dye on the fabric. This technique does not use toxic solutions and reduces the amount of water used in the process References [1] Tung, W.S., Daoud, W.A., Photocatalytic self-cleaning keratins: A feasilibility study, Acta Biomaterialia, 5, 50-56, 2009. Acknowledgement: CAPES, CNPq
