https://cyberleninka.org/article/n/768408.pdf

Mechanical properties of graphene and graphene-based nanocomposites

The effect of graphene dispersion on the mechanical properties of graphene/epoxy composites

Grafting of epoxy chains onto graphene oxide for epoxy composites with improved mechanical and thermal properties

Fabrication of exfoliated graphene-based polypropylene nanocomposites with enhanced mechanical and thermal properties

The incorporation of nanomaterials in the polymer matrix is considered to be a highly effective technique to improve the mechanical properties of resins. In this paper the effects of the addition of different nanoparticles such as single-walled CNT (SWCNT), double-walled CNT (DWCNT), multi-walled CNT (MWCNT), graphene, nanoclay and nanosilica on fracture toughness, strength and stiffness of the epoxy matrix have been reviewed. The Young's modulus (E), ultimate tensile strength (UTS), mode I (GIC) and mode II (GIIC) fracture toughness of the various nanocomposites at different nanoparticle loadings are compared. The review shows that, depending on the type of nanoparticles, the integration of the nanoparticles has a substantial effect on mode I and mode II fracture toughness, strength and stiffness. The critical factors such as maintaining a homogeneous dispersion and good adhesion between the matrix and the nanoparticles are highlighted. The effect of surface functionalization, its relevancy and toughening mechanism are also scrutinized and discussed. A large variety of data comprised of the mechanical properties of nanomaterial toughened composites reported to date has thus been compiled to facilitate the evolution of this emerging field, and the results are presented in maps showing the effect of nanoparticle loading on mode I fracture toughness, stiffness and strength.

/pdf/improving-the-fracture-toughness-and-the-strength-of-epoxy-2wqzw19lab.pdf

Improving the fracture toughness and the strength of epoxy using nanomaterials – a review of the current status

Epoxy/graphene platelets nanocomposites with two levels of interface strength

DNA strands have to sample numerous states to find the alignment that maximizes Watson-Crick-Franklin base pairing. This process depends strongly on sequence, which affects the stability of the native duplex as well as the prevalence of non-native inter- and intra-molecular helices. We present a theory which describes DNA hybridization as a three stage process: diffusion, registry search, and zipping. We find that non-specific binding affects each of these stages in different ways. Mis-registered intermolecular binding in the registry search stage helps DNA strands sample different alignments and accelerates the hybridization rate. Non-native intramolecular structure affects all three stages by rendering portions of the molecule inert to intermolecular association, limiting mis-registered alignments to be sampled, and impeding the zipping process. Once inregister base-pairs are formed, the stability of the native structure is important to hold the molecules together long enough for non-native contacts to break.

Tam Thanh Phan

Papers

Epoxy/graphene platelets nanocomposites with two levels of interface strength

Beneficial and Detrimental Effects of Nonspecific Binding During DNA Hybridization