Presence of microcracks in concrete can diminish the service life of a structure. The injection of materials for filling the crack is proposed for facing this problem. The traditional materials used for sealing cracks present some drawbacks, such as the difficulties of inorganic materials for flowing to all the depth of the crack and the lack of compatibility with the cementitious matrix in the case of organic materials. In this work, the injection of colloidal nanosilica dispersed in water is proposed for filling microcracks in mortars. The effect of the injection procedure on the sealing performance of the colloidal nanosilica has been assessed. The ability of colloidal nanosilica for penetrating through the crack and its posterior gelification-solidification inside the crack after a curing period have been confirmed. The microscopic analysis of a cross-section of the crack indicates that the sealing ability of the nanosilica seems to be not only due to the filling of the crack but also to chemical interactions with the cementitious phases of the surrounding crack sides.
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http://dx.doi.org/10.3390/ma15186338 | DOI Listing |
Materials (Basel)
June 2024
Doctoral School, Reinforced Concrete Structures, Technical University of Civil Engineering, 020396 Bucharest, Romania.
In this paper, we study the influence of densified microsilica and colloidal nanosilica admixtures on the mechanical strength and the microstructural characteristics of special mortars used for immobilizing radioactive concrete waste. The experimental program focused on the replacement of cement with micro- and/or nanosilica, in different proportions, in the basic composition of a mortar made with recycled aggregates. The technical criteria imposed for such cementitious systems, used for the encapsulation of low-level radioactive waste, imply high fluidity, increased mechanical strength and lack of segregation and of bleeding.
View Article and Find Full Text PDFInt J Biol Macromol
June 2024
Key Laboratory of Modern Preparation of TCM, Ministry of Education, Jiangxi University of Chinese Medicine, Nanchang 330004, China. Electronic address:
Pickering emulsions seem to be an effective strategy for encapsulation and stabilization of essential oils. In this work, a novel raspberry-liked Pickering emulsion (RPE) loading Mosla chinensis 'Jiangxiangru' essential oil (MJO) was successfully engineered by using ethyl lauroyl arginate (ELA) decorated nanosilica (ELA-NS) as particles emulsifier. And the ELA-NS-stabilized MJO Pickering emulsion (MJO-RPE) was further prepared into inulin-based microparticles (MJO-RPE-IMP) by spray-drying, using inulin as matrix formers.
View Article and Find Full Text PDFJ Colloid Interface Sci
September 2024
Engineering Research Center for Nanomaterials, Henan University, Kaifeng, 475004, China; Engineering Research Center for Nanomaterials Company Limited, Henan University, Jiyuan 459000, China.
Hydrophobic nano silica powder is a kind of important synergist to silicone defoaming agents. The large pore volume and branched chain conformation of silica nanoparticles present superior effects on defoaming properties. However, silica nanoparticles synthesized by liquid phase easily aggregate and pore collapse because of their high surface activity and polarity, leading to poorer dispersity and limited practicability.
View Article and Find Full Text PDFInt J Biol Macromol
May 2024
Marine Integrated Biomedical Technology Center, The National Key Research Institutes in Universities, Pukyong National University, Busan, Republic of Korea; Industry 4.0 Convergence Bionics Engineering, Pukyong National University, Busan, Republic of Korea; Major of Biomedical Engineering, Division of Smart Healthcare, College of Information, Pukyong National University, Busan, Republic of Korea. Electronic address:
Here, the simultaneous effect of chemo- and photothermal therapy against epidermoid carcinoma (EC) was investigated. A novel hydrogel, termed bionanogel (BNG), was designed using psyllium mucilage polysaccharide and bacterial gellan gum, incorporated with nanocomplex carrying caffeic acid (CA) and IR-820, and further characterized. The dual effect of BNG and 808 nm laser (BNG + L) on EC was investigated.
View Article and Find Full Text PDFACS Appl Mater Interfaces
March 2024
Department of Plant Pathology, Tamil Nadu Agricultural University, Coimbatore, Tamil Nadu 641 003, India.
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