Rupali Nagar

Title : Sol derived Three dimensional Growth of Tin Oxide Fractals

Abstract:

Fractal structures occur very often in nature as snowflakes, neuron network in human brain, mountains, trees, geometry etc. The complex structure has a governing power law that scales at different length-scales. This network which has repeating units possesses very interesting properties. In this work an attempt to grow fractals under lab environment is discussed. For this, sol-gel technique has been used to obtain SnO₂ fractals. By introducing chloride and hydroxyl ions in the reaction mixture, faster crystallization is achieved. Limited volumes of the gel, when dried, dry in different patterns. Based on the empirical evidence, the growth mechanism is proposed. When large volumes of gel are used, an interesting three-dimensional growth has been observed. Interestingly these structures continue to grow in the ambient condition vertically upwards, defying gravity. This clearly indicates that the gel network continues to expand with the help of little moisture present in the ambient. The growth process has been observed over a period of months, through different seasons and on large-scale substrate. The process is being understood to replicate or induce fractal formation in other metal oxide samples as well. Here, the role of hydrogen bonding is understood to aid in the network formation. Further, parameters like temperature and pressure will be discussed to understand the influence of ambient environment on the repeating unit of the fractal, fractal dimension, lacunarity, connectivity etc. The understanding of fractal formation and subsequent growth may be very helpful in simulating growth of skin tissue during wound repair, understand crack propagation in buildings, telecommunication improvements in antenna designs etc. 

What will audience learn from your presentation?

• Explaining what fractals are?
• Fractals have been used to solve many complex problems.
• Fractals have wide applicability ranging from biology, geology, material science, neural networks, communication, etc.
• Understanding the growth of fractals could open gateways for addressing problems of Li dendrite in batteries or help researchers in tissue growth for better healing of wounds, etc.

Biography:

Dr. Rupali Nagar studied Physics St. Stephen’s college, Delhi university, India as UG and at IIT Kanpur for Masters. She then joined the research group of Prof. J P Singh and Prof. B R Mehta at Indian Institute of Technology Delhi, New Delhi India and received her Ph.D degree in 2011. She then pursued her post-doctoral research in the research group of Prof. S. Ramaprabhu at Indian Institute of Technology Madras, Chennai, Tamil Nadu. She then joined Symbiosis Institute of Technology, Pune as Assistant Professor. She has established a research Lab Nanomaterials for Energy Applications at SIT. She has received 2 minor and one major research grant. She has published more than 20 papers, has 2 patents and published 2 book chapters.