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Patterning Processes for Polymer Brushes to Direct Assembly Christopher K. Ober, Cornell University, DMR 0518785. Brush Schematic. AFM Images. - PowerPoint PPT Presentation

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  • Conventionally, high resolution patterning of polymer brushes is done by first producing a patterned initiator layer on the substrate, followed by surface initiated polymerization of a suitable monomer.We have studied the possibility of directly patterning pre-grown polymer brushes using electron beam lithography. All polymer brushes were grown via surface initiated atom transfer radical polymerization (SI-ATRP). We have discovered that we can carry out sub-surface patterning of block copolymer brushes. Such types of 3D patterns could be useful in applications such as nanofluidic devices, waveguide materials, and directed nanowire assembly. With a diblock copolymer brush using a negative tone upper block and a positive tone lower block, 3D structures may be written with precise control of size and location using the direct patterning approach.

    Patterning Processes for Polymer Brushes to Direct Assembly Christopher K. Ober, Cornell University, DMR 0518785Figure: a) Illustration of PMMA-b-PS polymer brushes are grown via ATRP. b) Brushes patterned by e-beam and developed. Exposed PMMA is washed away while PS remains due to cross linking. c) PS top layer is etched away by oxygen plasma to prove the existence of nanochannels. Brush SchematicAFM Images

  • Ober has created and maintains the IUPAC Polymer Education website it is one of the Google, Bing and Yahoo top hits for this topicThis site (upper left) is designed to be a resource for students and teachersOber is leading efforts by the IUPAC Polymer Division to celebrate 2011, the International Year of Chemistry (IYC) including a writing and video contest on A World without PolymersOther outreach activities include hosting REU students, international student exchanges, involvement in teacher workshops and visits to local schoolsOn lower left, Ober and Prof. Zentel (Mainz) stand with recent exchange students

    Patterning Processes for Polymer Brushes to Direct Assembly Christopher K. Ober, Cornell University, DMR 0518785Picture(s)

    The investigation of polymer brushes has proven to be very interesting. We are now focused on study of block copolymer brushes that consist of a radiation scissionable block and a crosslinkable block. It is possible to create sub-surface patterns if a lower scissionable block is removed and the upper crosslinked block remains. We think this discovery has great possibility for the integration of a variety of nanotechnologies. We are preparing a manuscript for NanoLetters.*

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