scholarly journals Surprising transformation of a block copolymer into a high performance polystyrene ultrafiltration membrane with a hierarchically organized pore structure

2018 ◽  
Vol 6 (10) ◽  
pp. 4337-4345 ◽  
Author(s):  
R. Shevate ◽  
M. Kumar ◽  
M. Karunakaran ◽  
C. Canlas ◽  
K.-V. Peinemann

A novel strategy is developed for fabrication of high-flux isoporous polystyrene membranes from an ordered diblock copolymer by an alkaline degradation pathway.

2015 ◽  
Vol 30 (2) ◽  
pp. 171 ◽  
Author(s):  
CHEN Tao-Tao ◽  
LI Dan ◽  
JING Wen-Heng ◽  
FAN Yi-Qun ◽  
XING Wei-Hong

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Jeongpil Kim ◽  
Jeong-Hyun Eum ◽  
Junhyeok Kang ◽  
Ohchan Kwon ◽  
Hansung Kim ◽  
...  

AbstractHerein, we introduce a simple method to prepare hierarchical graphene with a tunable pore structure by activating graphene oxide (GO) with a two-step thermal annealing process. First, GO was treated at 600 °C by rapid thermal annealing in air, followed by subsequent thermal annealing in N2. The prepared graphene powder comprised abundant slit nanopores and micropores, showing a large specific surface area of 653.2 m2/g with a microporous surface area of 367.2 m2/g under optimized conditions. The pore structure was easily tunable by controlling the oxidation degree of GO and by the second annealing process. When the graphene powder was used as the supercapacitor electrode, a specific capacitance of 372.1 F/g was achieved at 0.5 A/g in 1 M H2SO4 electrolyte, which is a significantly enhanced value compared to that obtained using activated carbon and commercial reduced GO. The performance of the supercapacitor was highly stable, showing 103.8% retention of specific capacitance after 10,000 cycles at 10 A/g. The influence of pore structure on the supercapacitor performance was systematically investigated by varying the ratio of micro- and external surface areas of graphene.


2011 ◽  
Vol 287-290 ◽  
pp. 1420-1423 ◽  
Author(s):  
Wei Xing ◽  
Xiao Li ◽  
Xiu Li Gao ◽  
Shu Ping Zhuo

Highly porous carbons were prepared from sunflower seed shell (SSS) by chemical activation and used as electrode material for electrochemical double layer capacitor (EDLC). The surface area and pore structure of the porous carbons are characterized intensively using N2 adsorption technique. The results show that the pore-structure of the carbons is closely related to activation temperature. Electrochemical measurements show that the carbons have excellent capacitive behavior and high capacitance retention ratio at high drain current, which is due to that there are both abundant macroscopic pores and micropore surface in the texture of the carbons. More importantly, the capacitive performances of these carbons are much better than ordered mesoporous carbons, thus highlighting the success of preparing high performance electrode material for EDLC from SSS.


2015 ◽  
Vol 72 (7) ◽  
pp. 1198-1205 ◽  
Author(s):  
Kaixun Tian ◽  
Cuixiang Ming ◽  
Youzhi Dai ◽  
Kouassi Marius Honore Ake

The advanced oxidation of Cartap hydrochloride (Cartap) promoted by the Fenton system in an aqueous medium was investigated. Based on total organic carbon, chemical oxygen demand and high-performance liquid chromatography, the oxidation of Cartap is quite efficient by the Fenton system. Its long chain is easily destroyed, but the reaction does not proceed to complete mineralization. Ion chromatography detection indicated the formation of acetic acid, propionic acid, formic acid, nitrous acid and sulfuric acid in the reaction mixtures. Further evidence of nitrogen monoxide and sulfur dioxide formation was obtained by using a flue gas analyzer. Monitoring by gas chromatograph-mass spectrometer demonstrated the formation of oxalic acid, ethanol, carbon dioxide, and l-alanine ethylamide. Based on these experimental results, plausible degradation pathways for Cartap mineralization in an aqueous medium by the Fenton system are proposed.


2022 ◽  
pp. 2100834
Author(s):  
Ningning Xu ◽  
Dexing Zhao ◽  
Rui Wang ◽  
Qing Han ◽  
Yongxia Miao ◽  
...  

2009 ◽  
Vol 405-406 ◽  
pp. 197-203
Author(s):  
Bao Sheng Zhang ◽  
Li Juan Kong ◽  
Yong Ge

High performance concrete (HPC) with a water/cement ratio (w/c) of 0.32 and different lightweight aggregate (LWA) contents (0%, 25%, 50%, 75%, 100%) were prepared, and the influence of LWA on concrete frost-resistance and impermeability at different ages were studied, as well as the hydration degree, hydrated product, pattern and pore structure of the paste around aggregate. The results show that, by replacing normal weight aggregate (NWA) with 50% and 100% volume contents of pre-wetted LWA respectively, the chemical bound water of the cement paste surrounding aggregate are increased 12.1% and 22.7% as compared to concrete mixed without LWA. And at 28 days, lightweight aggregate concrete has the highest Ca(OH)2 content, whereas the 90-day Ca(OH)2 content of normal weight concrete is the highest. This proves that, with the increase of LWA content in concrete, both of the internal curing effect of pre-wetted LWA and secondary hydration effect of fly ash (FA) are strengthened, this can also be verified by the SEM study. Furthermore, the pore structure of the cement paste around aggregate can be improved consequently. The performance of frost-resistance of HPC can be improved by mixing LWA, the 90 day-frost-resistance of lightweight aggregate concrete is about 2.5 times of that of concrete mixed without LWA. The influence of LWA on the impermeability of HPC is different from normal concrete. When LWA content is more than 50%, the HPC impermeability decreased obviously, however at later age the difference between them becomes minor.


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