Intercalated water in graphite oxide (GO) was investigated by using different techniques: broadband dielectric spectroscopy (BDS) (10 -2 -10 9 Hz; 140-300 K), differential scanning calorimetry, X-ray diffraction, and attenuated total reflection geometry in Fourier transform infrared spectroscopy (ATR-FTIR). We have studied the water concentration (c w ) region from 0 wt % (anhydrous GO) up to 25 wt % since in this range the water crystallization is avoidable. The interlayer distance during hydration increases from 5.67 to 8 Å which corresponds to the uptake of a water monolayer in the interlayer space of GO. A clear relaxation due to water molecule reorientation is seen by BDS. The rotational water dynamics is dependent on the hydration level. At high water concentration (c w > 15 wt %), water-water interactions seem to dominate the dielectric response. This result is also compatible with those from FTIR and X-ray measurements. In this water concentration region, a slight dynamical crossover in the temperature dependence of the relaxation times is observed. We show that the crossover temperature on this system (T cross ) depends on the confinement size.

In this article we report the successful manufacture of a novel functionalized graphene sheet (FGS)/ silicone porous nanocomposite. Both the cellular microstructure and the properties of the porous nanocomposite were investigated in detail. The thermal properties show great stability and heat dissipation efficiency, highlighting their potential in applications with intense thermal requirements. Additionally, compression measurements indicate that there was a favourable interaction between the graphene nanosheets and the polymer.

ABSTRACT:The development of simple, efficient and robust strategies affording the facile construction of biomimetic organocatalytic nano-objects is currently a subject of great interest. Herein, a new pathway to artificial organocatalysts based on partially collapsed individual soft nano-objects displaying useful and diverse biomimetic catalytic functions is reported. Single-chain polymer nanoparticles endowed with enzyme-mimetic activity synthesized following this new route display: i) a relatively extended morphology under good solvent conditions, as revealed by small angle neutron scattering and coarse-grained molecular dynamics simulation results, ii) multiple, compartmentalized and accessible catalytic sites in which borane catalytic units are retained via B ... O interactions, and iii) unprecedented reductase and polymerase enzyme-mimetic properties.

Polymer intercalation into subnanometer graphite-oxide layers leads to the complete suppression of crystallization and α-relaxation processes. For the fi rst time, neutron spectroscopy shows that under these extreme confi nement conditions, the polymer phase adopts a planar zig-zag conformation, in no way resembling the characteristic helical structure of the bulk crystal.