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High refractive index polyimide (PI)–chloride modified carbon black hybrid materials were prepared. The introduction of chloride modified CBs endowed the PI/CB nanocomposites with high refractive index, and the effect of the interaction between the five-membered imide rings and aromatic rings of CBs on the high refractive indices and transparency of the resulting PI/CB nanocomposites was discussed. The refractive indices of the prepared hybrid films at 633 nm were in the range of 1.711–1.833, which increased with the CB content from 0 to 10 wt%. According to the comparison of the theoretical and experimental values, the higher refractive index is mainly due to the effective enhancement of intra- and intermolecular charge transfer (CT) interactions between the five-membered imide rings and chlorine atoms attached directly to the CBs and the adjacent benzene rings of CBs. A theoretical equation based on the modified Lorentz–Lorenz theory provided reasonably close estimation of the refractive indices to the experimentally observed values. Transmission electron microscopy results indicated that the incorporation of CBs into polymer matrices on the nanoscale would assure the optical transparency. [ABSTRACT FROM AUTHOR]

Our previous studies of raspberry-like carbon black/polystyrene (CB/PS) composite particles suggested that their morphologies could be tailored as the coverage degree of CB on PS microspheres. Morphologies of these composite particles were investigated by scanning electron microscope. The CB/PS composites prepared by using raspberry-like CB/PS particles had lower percolation threshold than that of general CB/PS composites. Optical microscopy photographs indicated that hierarchical structure of composite particles enabled CB particles to form more effective networks within the matrix. Raspberry-like structure dispersed CB particles in the interfaces between polycarbonate (PC) and PS when CB/PS particles were introduced into PC as additives. The effects of concentration of PS, coverage degree of CB, and concentration of CB on electrical properties of CB/PS/PC composite were investigated. The results showed that the percolation threshold of CB/PS/PC composite was improved when PS concentration was at the range of 20-80% and coverage degree of CB was more than 5% simultaneously. [ABSTRACT FROM AUTHOR]

The pH-responsive polyelectrolyte, named poly(methyl vinyl ether-alt-maleic anhydride) (PVM/MA), was grafted onto the surface of carbon black (CB) by ultrasonically degraded method. The effect of pH on the dispersion of PVM/MA grafted CB in water and waterborne polyurethane (WPU) was studied. Particle size of PVM/MA grafted CB and its transmission electron microscope images showed the increasing of pH in the suspension of grafted CB easily causes the aggregates of grafted CB. Furthermore, scanning electron microscope images showed grafted CB had better dispersibility than that of untreated CB in WPU emulsion or corresponding solid composite. When grafted CB was neutralized in aqueous solution, the compatibility between PVM/MA grafted CB and WPU got poor. In addition, the dispersion of grafted CB in solid composite could be controlled through tuning the composite resistance. [ABSTRACT FROM PUBLISHER]

Abstract: In our previous report, raspberry-like carbon black/polystyrene (CB/PS) composite microsphere was prepared through heterocoagulation process. Based on the previous study, in the present work, the morphology of raspberry-like CB/PS particle is tailored through adjusting the polarity and the concentration ratio of CB/PS colloidal suspension with the purpose to prepare particulate film for the fabrication of superhydrophobic surface. Scanning electron microscope (SEM) confirms the morphology of raspberry-like particle and the coverage of CB. Rough surfaces fabricated by raspberry-like particles with proper morphology are observed by SEM and clear evidence of superhydrophobic surface is shown. The structure of raspberry-like particle is analyzed by atom force microscope. The proposed relationship between the hydrophobicity and the structure of CB aggregates on the surface of PS microsphere is discussed in details. [Copyright &y& Elsevier]