Thermoelastic characterization of carbon nanotube reinforced PDMS elastomer

Internal energy and entropy contribution to the elasticity of carbon nanotube reinforced polydimethylsiloxane (PDMS) is evaluated using statistical theory of rubber elasticity. Stress–temperature measurements were performed and the data was used to calculate the internal energy contribution to elastic stress. Interesting aspects such as increase in energy and low entropy contribution to the elasticity of carbon nanotube reinforced PDMS is observed. This can be related t o the deformation behavior of the network chains of pristine elastomers and the directional reorientation of nanotube entanglements. While the entropy change is associated with reorientation or directional preference of the carbon nanotube entanglements, the internal energy change is associated with structural bending or stretching of the nanotubes. A reversible deformation of nanotube entanglements complements rubber like elasticity and the present study gives insights into the thermoelasticity of reinforced elastomers as well as the elastic behavior of carbon nanotube entanglements inside a polymer matrix.

Thermodynamics of adsorption of lysozyme on gold nanoparticles from second harmonic light scattering

Lysozyme adsorption on gold nanoparticles is an enthalpically driven process while the entropy contribution is favourable but insignificant.

The effect of shell closure on the thermodynamic properties of 207Pb and 89Y

Nuclear level densities of [Formula: see text]Pb and [Formula: see text]Y are calculated using the Lipkin–Nogami (LN) method and Bradeen–Cooper–Schrieffer (BCS) model. It is revealed that the calculated nuclear level densities are highly matched with the experimental data of Oslo group. The excitation energy and entropy are calculated for mentioned nuclei. In the case of two studied nuclei the characteristic of being magic for the number of neutrons or protons causes the decrease of the excitation energy and entropy contribution of magic system at low temperatures.