• MENEKA BANIK

      Articles written in Bulletin of Materials Science

    • Hydrophobic recovery of cross-linked polydimethylsiloxane films and its consequence in soft nano patterning

      NANDINI BHANDARU NEHA AGRAWAL MENEKA BANIK RABIBRATA MUKHERJEE ASHUTOSH SHARMA

      More Details Abstract Fulltext PDF

      Cross-linked polydimethylsiloxane (PDMS) films and surfaces obtained by thermal cross-linking of commercially available Sylgard 184 are widely utilized in many areas of science, due to superior thermal stability, low dielectric constant, transparency and biocompatibility. Cross-linked PDMS surfaces are weakly hydrophobic and several experiments, particularly the ones that utilize capillary-driven microscale flow require the modulation of the surface wettability. A well-known strategy to achieve the same is by exposing the Sylgard 184 surface to UV/ozone (UVO) treatment at room temperature. Depending on the duration of exposure, the wettability drops from hydrophobic to a nearcompletewetting (water contact angle $\sim$10$^{\circ}$), due to the formation of a surface oxide layer. However, under normal atmospheric conditions, these surfaces recover their hydrophobicity over a period of time due to diffusive migration of the uncrosslinked oligomers to the surface, and formation of a hydrophobic dimethyl silicone layer. We explore the hydrophobic recovery process as a function of cross-linker concentration and UVO exposure time and show how a partially or fully recovered PDMS stamp may influence subsequent nanopatterning, including the possible creation of features with different morphology using a single stamp.

  • Bulletin of Materials Science | News

    • Dr Shanti Swarup Bhatnagar for Science and Technology

      Posted on October 12, 2020

      Prof. Subi Jacob George — Jawaharlal Nehru Centre for Advanced Scientific Research, Jakkur, Bengaluru
      Chemical Sciences 2020

      Prof. Surajit Dhara — School of Physics, University of Hyderabad, Hyderabad
      Physical Sciences 2020

    • Editorial Note on Continuous Article Publication

      Posted on July 25, 2019

      Click here for Editorial Note on CAP Mode

© 2017-2019 Indian Academy of Sciences, Bengaluru.