No abstract

No abstract

We introduce a facile method to synthesize a new class of coreshell microspheres composed of resin core particles coated with various carbon materials. The coreshell microspheres were prepared by a one-pot process in which carbon materials such as edge-exfoliated graphite and expanded graphite were dispersed together with core substrates like polystyrene and poly(styrene/2-hydroxyethyl methacrylate) spherical particles in supercritical carbon dioxide. The obtained microspheres were characterized by thermogravimetric analysis, Raman spectroscopy, and scanning electron microscopy. The results indicate that the carbon shells are tightly attached to the surface of the core substrates. Furthermore, because of excellent adhesion, the carbon-coated polymer particles exhibited extremely high electrical conductivity with particle resistance of less than 50 ³ cm despite the presence of an insulating polymeric core material.

This paper introduces a new carbon material having high electrical conductivity and dispersibility, which is characterized by a partially exfoliated structure with grafted polymer and restacking ability through removal of the grafted polymer.

This paper demonstrates that novel composites of porous silica with carbon-like black materials are different from conventional carbon black. The obtained black composites maintained high porosity of the base silica and exhibited extremely high molecular shape selectivity, especially for geometrical isomers.Keywords: π-Conjugated structure | Porous material | Amorphous carbonTo address the growing demand for enhanced separation selectivity in column technology, a variety of functional molecules have been designed and immobilized on porous carriers to meet this demand, as exemplified by successful applications of macrocycle-grafted silica, 15 where high selectivity is achieved by macrocyclic ordering of heteroatoms as interaction points. On the other hand, non-macrocyclic compounds can also achieve selectivity enhancement if weak interaction points are integrated and oriented. Typical examples include integrated carbonyl group systems like side-chain ordered polymers containing ester bonds, 68 alternating phthalimide-based copolymers, 9 and polypeptide-10 and molecular-gel-based ordered organic phases, 1113 which provide higher selectivity than conventional hydrophobized silica, especially for separating geometrical isomers. These successful applications are directly related to the promotion of multiple carbonyl-π interactions 14 with guest molecules. π-Electron-rich organic phases are also attractive for selectivity enhancement. Although ππ interactions are considerably weaker than carbonylπ interactions, 14,15 integration of aromatic π-moieties enables selectivity enhancement, as exemplified by polymers with aromatic side chains, 16,17 Herein, we introduce a new class of π-electron-rich organic phases (Figure 1) for ultra-selective adsorption, which are based on carbon-like black materials different from conventional carbon black and graphite. The designed materials exhibit the following advantages. (1) The pre-black organic thin layer can be created on porous silica microspheres by direct copolymerization of 1,5-dihydroxynaphthalene (DHN) and 1,3,3, 27 in a simple solvent system. The amount of immobilized material is easy to adjust while preserving the large surface area of porous silica, since polymerization occurs on the silica surface in a semi-quantitative fashion. Additionally, polymer growth does not require silica to be surface-treated. (2) Copolymerization is accompanied by crosslinking; therefore, no elution is observed after washing with solvents. (3) The adhered polymer can be converted into carbonlike black materials by heat treatment at a suitable temperature, allowing the adsorptivity and selectivity of the column system to be flexibly tuned.Copolymerization was carried out at a fixed molar ratio (1:1) of DHN and TMTA. The original milky white mixture of these monomers with YMC silica as porous carrier in ethanol turned green after 1 h stirring at reflux temperature (78°C). Optical microscopy imaging indicated that the above change was due to the coloration of silica and not that of the solvent....