Introduction
Hello Everyone,
My name is Archana Chaudhary, I have taught Physics (which I really love) and Mathematics for more than 15 years. My specialty is teaching 9th – 12th in these subjects.
Being from a village myself (completed my Master’s degree) I understand how difficult it is for girls to study STEM subjects in that environment. (Science / Technology / Engineering / Mathematics). Despite desiring to do so, they are encouraged to take up other topics for which they wont have to travel or go outside their home towns.
This YouTube channel is an effort to reach them and support their education and at the same time allowing me to reach a larger audience and effect more students.
Educational Qualifications
M. Tech. Nanotechnology – Vellore Institute of Technology – 9.27 CGPA
M. Sc. Physics – Chaudhary Charan Singh University – 80%
B. Sc. General – Chaudhary Charan Singh University – 75%
Published Resarch
As part of my M. Tech. in Nanotechnology, I did practical research and published two research papers, they are listed below.
Abstract
An inexpensive and facile one-step method to develop a superhydrophobic coating on the copper surface is reported. Superhydrophobic CuO/Cu(OH)2 surfaces were prepared by a simple solution-immersion process at room temperature, without using a low surface energy material. The structure and composition of as-prepared CuO/Cu(OH)2 hierarchical structure were confirmed by X-ray diffraction, micro-Raman spectroscopy, and X-ray photoelectron spectroscopy (XPS). The growth stage was carefully examined by field emission scanning electron microscopy (FESEM), and it was observed that initially Cu(OH)2 nanoneedle arrays were formed on the copper surface and subsequently the CuO microflowers formed on the nanoneedle arrays. The contact angle as a function of immersion time was studied using a contact angle goniometer. The correlation between the microstructure of the immersed copper surface and the contact angle was examined carefully using FESEM and atomic force microscopy (AFM). Our results based on FESEM and AFM studies show that the CuO/Cu(OH)2 coatings demonstrate superhydrophobicity only for an optimal combination of the solid region (i.e., microflowers and nanoneedles) and air pockets (i.e., voids). The maximum static water contact angle on the prepared surface was 159°. The wettability transition of the CuO/Cu(OH)2 surface from superhydrophobicity to superhydrophilicity was studied by the alteration of oxygen plasma treatment and dark storage. The FESEM, AFM, and XPS studies showed that this transformation was mainly due to the morphological changes that occur in addition to the chemical changes taking place on the CuO/Cu(OH)2 surface under the influence of oxygen plasma. XPS analysis demonstrated that the incorporation of oxygen species by oxygen plasma activation accounted for the highly hydrophilic character of the surface.
Abstract
The wettability of reactively sputtered Y₂O₃, thermally oxidized Y-Y₂O₃ and Cd-CdO template assisted Y₂O3 coatings has been studied. The wettability of as-deposited Y₂O3 coatings was determined by contact angle measurements. The water contact angles for reactively sputtered, thermally oxidized and template assisted Y₂O3 nanostructured coatings were 99°, 117° and 155°, respectively. The average surface roughness values of reactively sputtered, thermally oxidized and template assisted Y₂O3 coatings were determined by using atomic force microscopy and the corresponding values were 3, 11 and 180 nm, respectively. The low contact angle of the sputter deposited Y₂O₃ and thermally oxidized Y-Y₂O₃ coatings is attributed to a densely packed nano-grain like microstructure without any void space, leading to low surface roughness. A water droplet on such surfaces is mostly in contact with a solid surface relative to a void space, leading to a hydrophobic surface (low contact angle). Surface roughness is a crucial factor for the fabrication of a superhydrophobic surface. For Y₂O₃ coatings, the surface roughness was improved by depositing a thin film of Y₂O3 on the Cd-CdO template (average roughness = 178 nm), which resulted in a contact angle greater than 150°. The work of adhesion of water was very high for the reactively sputtered Y₂O₃ (54 mJ/m²) and thermally oxidized Y-Y₂O₃ coatings (43 mJ/m²) compared to the Cd-CdO template assisted Y₂O₃ coating (7 mJ/m²).
