Heesup Choi; Masumi Inoue; Risa Sengoku; Hyeonggil Choi
Volume 8, Issue 10 , October 2017, , Pages 993-998
Abstract
In this study, it is possible to disperse effectively cracked using synthetic fiber, an examination of the most suitable self-healing conditions was performed on the above crack width 0.1mm. As a result, effective crack dispersion using polyvinyl alcohol (PVA) fibers with polar OH - groups, as well as ...
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In this study, it is possible to disperse effectively cracked using synthetic fiber, an examination of the most suitable self-healing conditions was performed on the above crack width 0.1mm. As a result, effective crack dispersion using polyvinyl alcohol (PVA) fibers with polar OH - groups, as well as improved self-healing for cracks that are larger than 0.1 mm in width, posing concerns of CO2 gas and Cl - penetration, were observed. Also, CO3 2- reacts with Ca 2+ in the concrete crack, resulting in the precipitation of a carbonate compound, CaCO3. Based on this, it is deemed possible for the recovery of effective water tightness and strength recovery through effective freezing-thawing resistance to be made from cracks that are larger than 0.1 mm in width. In addition, it was determined that, as for the most suitable self-healing conditions in the inside and surface of the cracks, calcium hydroxide (Ca(OH)2) solution with CO2 micro-bubble was more effective in promoting the self-healing capability than water with CO2 micro-bubble.
Vishal S. Makadia; Lalit M. Manocha; Satish Manocha; Hasmukh L. Gajera
Volume 8, Issue 3 , March 2017, , Pages 262-264
Abstract
A freeze-thaw technique is put forth as a novel approach to exfoliating graphene oxide sheets (GO-sheets) in aqueous media. This method does not use shear force or high-temperature treatment at any stage. Avoiding these factors prevents scrolling and promotes defect-free synthesis of the graphitic ...
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A freeze-thaw technique is put forth as a novel approach to exfoliating graphene oxide sheets (GO-sheets) in aqueous media. This method does not use shear force or high-temperature treatment at any stage. Avoiding these factors prevents scrolling and promotes defect-free synthesis of the graphitic planes. The research shows how the freeze-thaw technique successfully exfoliates graphitic planes without producing scrolls or defective graphene oxide planes. Further, when compared to conventional exfoliation methods, it was found that the freeze-thaw technique increased the surface area significantly.
