다중혈관 관상동맥 환자에서 y-문합을 이용하여 양쪽 내흉동맥만을 사용한 우회술의 조기 성적

[신간의 별자리x] 우리/미술, 그리고 ‘슬픔의 박물관’

Supercapacitors, also called ultracapacitors or electrochemical capacitors, store electrical charge on high-surface-area conducting materials. Their widespread use is limited by their low energy storage density and relatively high effective series resistance. Using chemical activation of exfoliated graphite oxide, we synthesized a porous carbon with a Brunauer-Emmett-Teller surface area of up to 3100 square meters per gram, a high electrical conductivity, and a low oxygen and hydrogen content. This sp 2 -bonded carbon has a continuous three-dimensional network of highly curved, atom-thick walls that form primarily 0.6- to 5-nanometer-width pores. Two-electrode supercapacitor cells constructed with this carbon yielded high values of gravimetric capacitance and energy density with organic and ionic liquid electrolytes. The processes used to make this carbon are readily scalable to industrial levels.

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Carbon-based Supercapacitors Produced by Activation of Graphene

Kenji Sumida, David L. Rogow, Jarad A. Mason, Thomas M. McDonald, Eric D. Bloch, Zoey R. Herm, Tae-Hyun Bae, Jeffrey R. Long

Carbon Dioxide Capture in Metal–Organic Frameworks

Carbon properties and their role in supercapacitors

Publisher Summary
This chapter describes methods of chemical activation of carbons involving the co-carbonization of a parent feedstock with a chemical. Three chemicals that are widely used include zinc chloride, phosphoric acid and potassium hydroxide/carbonate. An overview of the comparative behaviors of these three agents, using very similar parent feedstocks is presented and concluded with the suitability of such activated carbons for methane storage. An in-depth analysis of the chemistry of activation by phosphoric acid (H3PO4) is presented. Moreover, an in-depth analysis of the chemistry of activation by potassium salts is also presented. The chapter also discusses intercalation chemistry and reviews additional relevant information. Activated carbons, with microporosity and controlled pore-size distributions, are prepared from: (i) synthetic carbon precursors mainly of polymeric type (polyimide, polyvinyl chloride, and resins) and (ii) the more conventional precursors, such as lignocellulosic materials. Chemical activation of lignocellulosic materials is mainly directed toward the preparation of powdered activated carbons. Porosity and pore-size distributions are determined by gas adsorption and immersion calorimetry, with the measurement of helium and bulk densities.

CHAPTER 6 – Activation Processes (Chemical)

Preparation of activated carbon cloths from viscous rayon. Part III. Effect of carbonization on CO2 activation

Several activated carbons obtained from commercial sources have been tested for their ability to remove mercuric chloride (HgCl2) from aqueous solutions. The chemical nature of the surface of the activated carbons was changed by introducing carbon-oxygen and carbon-sulphur surface complexes. The influence of these types of complexes on the adsorption of HgCl2 by the activated carbons has been studied. It seems that the existence of hydroquinonic, phenolic and hydrosulphide groups on the surface of the carbon reduces Hg(II) to Hg(I). However, there was an increase in the adsorption of Hg(II) when sulphide or hydrosulphide groups were present on the surface of the carbon. The effect of the pH of the solutions on HgCl2 adsorption was also studied; when the pH was changed from 1 to 7 there was an enhancement of the adsorption of HgCl2 by the activated carbons.

Effect of carbon‐oxygen and carbon‐sulphur surface complexes on the adsorption of mercuric chloride in aqueous solutions by activated carbons

Adsorption of CO2 and SO2 on activated carbons with a wide range of micropore size distribution

The porous structure of nanostructured silicas MCM-41 and SBA-15 has been characterized using N2 adsorption at 77 K, before and after n-nonane preadsorption, together with immersion calorimetry into liquids of different molecular dimensions. Selective blocking of the microporosity with n-nonane proves experimentally that MCM-41 is exclusively mesoporous while SBA-15 exhibits both micro- and mesopores. Additionally, N2 adsorption experiments on the preadsorbed samples show that the microporosity on SBA-15 is located in intrawall positions, the micropore volume accounting for only ∼7−8 % of the total pore volume. Calorimetric measurements into n-hexane (0.43 nm), 2-methylpentane (0.49 nm), and 2,2-dimethylbutane (0.56 nm) estimate the size of these micropores to be ≤0.56 nm.

Francisco Rodríguez-Reinoso

Papers

CHAPTER 6 – Activation Processes (Chemical)

Preparation of activated carbon cloths from viscous rayon. Part III. Effect of carbonization on CO2 activation

Effect of carbon‐oxygen and carbon‐sulphur surface complexes on the adsorption of mercuric chloride in aqueous solutions by activated carbons

Adsorption of CO2 and SO2 on activated carbons with a wide range of micropore size distribution

Is there any microporosity in ordered mesoporous silicas