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and even hair care products [47]. Its unusual flow properties also allow it to
conform to very small features if allowed to flow for an extended period, and as
such, commercial PDMS compounds have seen much success in the field of
microfuidics [49]. For the current work, the PDMS used was Sylgard 184, as
provided by Dow Corning, which comes in a two-part mixture which includes the
PDMS monomer and a curing agent which induces the PDMS chains to covalently
link together and form a highly-compliant solid.
Poly(dimethylsiloxane) (PDMS) was selected as the matrix for these
composites due to its extremely high wetting of CNTs [35], in addition to the fact
that it is commercially available and easy to work with. As with other elastomers,
PDMS is very elastic and extremely compliant at room temperature. To achieve
large-amplitude strains, the testing needs to be conducted while the polymer is in
the “rubbery” state, so choosing a matrix with a very low glass transition (Tg) such
as PDMS (-129 oC) is ideal.
3.2. Composite Preparation
The infiltration technique used was very similar to the method used in the
paper which introduced these continuously-aligned CNT-reinforced composites
[46]. A detailed procedure is as follows:
1. Mix the PDMS monomer and the curing agent at a 10:1 ratio and stir for 5
minutes to ensure homogeneity.