Composite Materials

UHMWPE fiber reinforced epoxy composite

  • Surface modification of UHMWPE fiber and characterization by SEM, ATR, XPS
  • Epoxy curing with Amine cross-linkers (reference) and epoxy/fiber composite fabrication and testing
  • The adhesion between PE fiber and epoxy matrix can be significantly improved (e.g. shear strength can be increased three times) after polar functional groups (-OH, -COOH, -CO, etc) are introduced onto fiber surface by chemical etching, UV-initiated grafting, plasma treatment, and/or plasma initiated grafting reactions.

  • Made a plasma surface treatment tool like the following, which can be used as a PECVD tool also.
Sources: https://lnf-wiki.eecs.umich.edu/wiki/File:PECVD_chamber_diagram.jpg
  • An interesting technique was used in the work to measure the radical amount on fiber surfaces based on the following reaction (DPPH’s pink color becomes pale after reaction with radicals).
Color change of DPPH/CCl4 solution before/after reaction with radicals (refernece 1, 2)

Chemical Etching

Surface modification PE fibers by chemical etching

Plasma Treatment

UV initiated grafting

Surface modification by UV-initiated grafting organic segment on PE fiber surface

Plasma initiated Grafting