Institute for Nanotechnology (INT)-Nano-Materials, CNT & Inkjet Printing Process Research Group

Group leader Prof. Dr. Hab. DANG Mau Chien Other members 1. Dr. Fribourg-Blanc Eric 2. MSc. DANG Thi My Dung (PhD. Stud.) 3. MSc. LE Duy Dam (PhD. Stud.) 4. MSc. TRINH Dung Chinh 5. BSc. HUYNH Kim Khanh Introduction: *A. About activities in Titanium dioxide nanomaterial Research* For making self-cleaning and antibacterial nanomaterials, LNT has launched the process of manufacturing photocatalytic films based on N-SiO₂-TiO₂ by sol-gel method on ceramic tiles. Self-cleaning properties of N-SiO₂-TiO₂ film on the surface of ceramic tiles were demonstrated by the discoloration of Metylen Mlue (MB) under the effect of visible light. The results showed that biodegradable organic matter is excellent. After 15 minutes, MB deposited on ceramic tiles decomposed at almost half level. After 20 minutes, it was almost completely destroyed, while the MB in the control samples remained unchanged (Figure 1). In addition, antibacterial properties were tested by the method of counting the number of E.Coli colonies on Petri dishes (Figure 2). Some images

*Figure* 1. Decoloration color of MB on ceramic tiles versus time: a) Coated samples, b) Uncoated sample as control samples.

*Figure* 2. Testing antibacterial property of nanothin film: a) The colonies on control Sample Dishes b) The colonies on N- TiO₂/SiO₂ Petri Dishes (much fewer while compare with control samples dishes)
*B. About activities in Cacbon Nano tube (CNT) Research* Electrical properties of CNTs draw are very attractive for many applications. With extremely small size and high symmetry, CNTs have special quantum effects and amazing electronic, magnetic and optical properties. Among such properties, the ability of CNTs field emission is the most attractive with features such as low voltage, stability and high capacity. In this project, we study synthesis of carbon nanotubes by Thermal Chemical Vapor Deposition method on a variety of different metal catalysts. With modern equipment analysis in Laboratory for Nanotechnology and the collaboration with the Center for Nanotubes and Nanostructured Composite (CNNC), South Korea we have improved steps by steps the synthesis process of CNTs and study their characteristics to apply for field emission devices. Some images
*Figure 3*. SEM image of Carbon nanotubes on Si wafer
*Figure 4*. FE-TEM images of CNTs
*C. About activities in Inkjet* *Printing Process Research* Inkjet is an interesting technology for addressing microfabrication situations where a resolution is not the primary concern, i.e. above 15-µm linewidth. It is considered a complementary tool in the field of microfabrication to reduce the cost through the absence of mask and great versatility. The application chosen for starting inkjet process exploration is printing of metallic traces. Using commercial silver nanoparticle inks, the LNT is developing the understanding of jetting metallic inks. All printing developments are based on the standard Dimatix® printer. This versatile tool allows for careful study of ink jetting as well as printing process. The primary requirement for proper inkjet printing is to obtain stable ejection of droplets and nozzle-to-nozzle identical speed. The first stage of development for mastering the process is underway with commercial silver inks. The main interest at this stage is to strengthen the theoretical understanding of droplet ejection in inkjet. Voltage, temperature, vacuum and other parameters pertinent to jetting are modified to visually control the droplet ejection. The LNT is underway to demonstrate electrical circuit printing on plastic substrates, in-line with the best results obtained abroad. At the same time, a study is underway to develop a copper ink aimed at reducing the cost of metallic traces fabrication. Synthesized copper nanoparticles can be seen in Figure 5. Some Images
*Figure* 5. Freshly Prepared red Cu Sol (1)/ Black color (2)/ violet color (3)/ upon onset oxidation (4)
Conducted Projects 1. Study on fabricating TiO₂ nanomaterial for self-cleaning and sterilizing products 2. Study on fabrication self-cleaning and antibacterial nanomaterial on ceramic tiles 3. Study on integration of carbon nano tube on micro hotplate 4. Study on fabricating carbon nano tube and investigating its application capacity in field emission device 5. Investigation of fundamental parameters of inkjet printing technique for printing of conductive traces and films 6. Copper nanoparticule synthesis and copper inkjet ink formulation Publications Duy Dam Le, Thi My Dung Dang, Vinh Thang Chau and Mau Chien Dang 2010 The fabrication of visible light responsive Ag-SiO₂ co-doped TiO₂ thin films by the sol–gel method Adv. Nat. Sci: Nanosci. Nanotechnol. 1 015007 Thi My Dung Dang, Duy Dam Le, Vinh Thang Chau and Mau Chien Dang 2010 Visible-light photocatalytic activity of N/SiO₂–TiO₂ thin films on glass Adv. Nat. Sci: Nanosci. Nanotechnol. 1 015004 Dang Thi My Dung, Le Duy Dam, Chau Vinh Thang and Dang Mau Chien 2009 Synthesis of visible-light active SiO₂/TiO₂ photocatalysts by nitrogen doping Proceedings of IWNA 2009 (Vung Tau, Vietnam, 12-14 November 2009) pp 275-279 Le Duy Dam, Dang Thi My Dung, Nguyen Dang Giang, Chau Vinh Thang and Dang Mau Chien 2009 Enhancement of photocatalysis on Ag-SiO₂ co-doped TiO₂ thin films Proceedings of IWNA 2009 (Vung Tau, Vietnam, 12-14 November 2009) pp 499-503 Dang Mau Chien, Nguyen Ngoc Viet, Nguyen Thi Kieu Van and Nguyen Thi Phuong Phong 2009 SiO₂-TiO₂ thin film and its photocatalyst properties Advances in Natural Sciences (ANS) 10 31-38 Dang Mau Chien, Nguyen Ngoc Viet, Nguyen Thi Kieu Van and Nguyen Thi Phuong Phong 2009 Characteristics modification of TiO₂ thin film by doping with silica and alumina for self-cleaning application Journal of Experimental Nanoscience (JEN) 4 221-232 Nguyen Thi Phuong Phong, Nguyen Ngoc Viet, Nguyen Thi Kieu Van and Dang Mau Chien 2007 Research on fabricating aluminum doped TiO₂ thin film and its water repellent property Proceedings of IWNA 2007 (Vung Tau, Vietnam, 15-17 November 2007) pp 208-214 Nguyen Ngoc Viet, Nguyen Thi Phuong Phong, Nguyen Thi Kieu Van and Dang Mau Chien 2007 Preparation of anatase TiO₂ nanoparticles and nanocomposite TiO₂/ PCVA by sol-gel method Proceedings of IWNA 2007 (Vung Tau, Vietnam, 15-17 November 2007) pp 476-480 Nguyen Thi Kieu Van, Nguyen Ngoc Viet, Nguyen Thi Phuong Phong, Dang Mau Chien 2007 Study on structure and properties TiO₂ nanomaterial on ceramic tiles Proceedings of IWNA 2007 (Vung Tau, Vietnam, 15-17 November 2007) pp 489-492 Collaborations 1. Center for Nanotubes and Nanostructured Composites, Sungkyunkwan University, Suwon 440-746, Korea. Web: http://cnnc.skku.ac.kr/e-index.html 2. Institute of Microtechnology - University of Neuchâtel, Swisszerland. Contact Information MSc. DANG Thi My Dung - Researcher Phone: +84 08 3 7242160 (ext 4623) - Fax: +84 08 3 7242163 Email: dtmdung@vnuhcm.edu.vn <Back to Reseach Group>