A simulation study on the effect of nanoparticle size on the glass transition temperature of polymer nanocomposites.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 34525159.
- Also identified by DOI 10.1039/d1sm00843a.
- No licence information is recorded for this record.
- Because redistribution is not established, this page shows the abstract only. Follow the links below for the full text.
Abstract
The effect of the size of nanoparticles, <i>σ</i><sub>NP</sub>, on the glass transition temperature, <i>T</i><sub>g</sub>, of polymer nanocomposites is studied by using molecular dynamics simulations. The variation of <i>T</i><sub>g</sub> with <i>σ</i><sub>NP</sub> shows two distinct behaviours for polymer nanocomposites at low and high volume fractions of nanoparticles (<i>f</i><sub>NP</sub>). At a low <i>f</i><sub>NP</sub>, <i>T</i><sub>g</sub> decays almost exponentially with <i>σ</i><sub>NP</sub>, whereas at a high <i>f</i><sub>NP</sub><i>T</i><sub>g</sub> shows a complex behaviour: it initially increases and then decreases with increasing <i>σ</i><sub>NP</sub>. The decrease in <i>T</i><sub>g</sub> with <i>σ</i><sub>NP</sub> is due to the significant decrease of adsorbed polymer monomers, while the increase in <i>T</i><sub>g</sub> with <i>σ</i><sub>NP</sub> is attributed to the slower diffusion of larger nanoparticles. We have also investigated the diffusion and relaxation of polymer chains at a temperature above <i>T</i><sub>g</sub> for both low and high <i>f</i><sub>NP</sub>s. The diffusion constant and relaxation time of polymer chains are highly consistent with the behaviour of <i>T</i><sub>g</sub>.