Chromatographic Assessment of Organic Compounds Using Carbon Nanotubes: The Relationship between Affinity and Dispersibility.

The affinity between carbon nanotubes (CNTs) and organic compounds is of substantial importance since it strongly relates to the dispersibility of CNTs in those compounds. Several affinity evaluation methods have been developed so far, and the concept of the Hansen solubility parameter is a representative method widely used in the field of nanocarbon materials. Here, we demonstrate that CNT-loaded silica columns can effectively assess the affinity of organic compounds for CNT surface by exploiting the chromatographic retention time as a criterion.

Radical scavenging activity of carbon nanotubes: toward appropriate selection of a radical initiator.

Radical scavenging activities are attractive properties not only for scientific fields biomedicine, but for the materials industry. In this study, we report that carbon nanotubes (CNTs) can scavenge radicals from organic peroxides, while radicals from azo-type radical initiators exhibit only a few effects from the presence of CNTs. In addition, experimental results suggest the possibility that captured peroxide radicals generate active radical sites on the CNT surface, from which polymerization can take place.

Transparent, Superflexible Doubly Cross-Linked Polyvinylpolymethylsiloxane Aerogel Superinsulators via Ambient Pressure Drying.

Aerogels have many attractive properties but are usually costly and mechanically brittle, which always limit their practical applications. While many efforts have been made to reinforce the aerogels, most of the reinforcement efforts sacrifice the transparency or superinsulating properties. Here we report superflexible polyvinylpolymethylsiloxane, (CHCH(Si(CH)O)), aerogels that are facilely prepared from a single precursor vinylmethyldimethoxysilane or vinylmethyldiethoxysilane without organic cross-linkers.

Aerogels from Chloromethyltrimethoxysilane and Their Functionalizations.

Reactions of chloromethyltrimethoxysilane (CMTMS) and its derived colloidal network polychloromethylsilsesquioxane (PCMSQ) have been investigated to extend the material design strategy toward functionalized and mechanically reinforced aerogels. In a carefully designed sol-gel system, CMTMS has afforded transparent aerogels in the presence of cationic surfactant. The surface chloromethyl groups with polarity and reactivity are shown to be useful for supporting nanostructures, with photoluminescent carbon dots (C-dots) prepared from polyethylenimine and citric acid as an example.

Transparent Ethenylene-Bridged Polymethylsiloxane Aerogels: Mechanical Flexibility and Strength and Availability for Addition Reaction.

Transparent, low-density ethenylene-bridged polymethylsiloxane [Ethe-BPMS, O(CH)Si-CH═CH-Si(CH)O] aerogels from 1,2-bis(methyldiethoxysilyl)ethene have successfully been synthesized via a sol-gel process. A two-step sol-gel process composed of hydrolysis under acidic conditions and polycondensation under basic conditions in a liquid surfactant produces a homogeneous pore structure based on cross-linked nanosized colloidal particles. Visible-light transmittance of the aerogels varies with the concentration of the base catalyst and reaches as high as 87% (at a wavelength of 550 nm for a 10 mm thick sample).

Silicone-Based Organic-Inorganic Hybrid Aerogels and Xerogels.

Aerogels are attracting increasing attention due to their high thermal insulation ability as well as unique properties such as high porosity, surface area, and transparency. However, low mechanical strengths, originating from their unique porous structure, impede handling, formability, mass production, and extended applications. This minireview focuses on the strengthening of aerogels by several organic-inorganic hybridization strategies.

Transparent Ethylene-Bridged Polymethylsiloxane Aerogels and Xerogels with Improved Bending Flexibility.

Transparent, monolithic aerogels with nanosized colloidal skeletons have been obtained from a single precursor of 1,2-bis(methyldiethoxysilyl)ethane (BMDEE) by adopting a liquid surfactant and a two-step process involving strong-acid, followed by strong-base, sol-gel reactions. This precursor BMDEE forms the ethylene-bridged polymethylsiloxane (EBPMS, O(CH)Si-CHCH-Si(CH)O) network, in which each silicon has one methyl, two bridging oxygens, and one bridging ethylene, exhibiting an analogous structure to that of the previously reported polymethylsilsesquioxane (PMSQ, CHSiO) aerogels having one methyl and three bridging oxygen atoms. Obtained aerogels consist of fine colloidal skeletons and show high visible-light transparency and a flexible deformation behavior against compression without collapse.

Strong desmin expression in a congenital desmoplastic infantile ganglioglioma mimicking pleomorphic rhadomyosarcoma: a case report including ultrastructural and cytogenetic evaluation and review of the literature.

Purpose: Desmoplastic infantile gangliogliomas (DIGs) are rare tumors of infancy. Herein, we describe an unusual case of DIG diagnosed by prenatal ultrasound.

Methods: This 5-day-old newborn was delivered after a prenatal ultrasound revealed a large cystic mass in the left cerebral hemisphere along with an echogenic solid component.