Nano-structured calcium silicate hydrate functionalised with iodine

Borrmann, Thomas; Johnston, James H.; McFarlane, Andrew J.; Richardson, M.J.; O’Connor, Sean

doi:10.1016/j.jcis.2009.07.012

Cited by 10 publications

(3 citation statements)

References 24 publications

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“…Figure 6 is the intensity ratio of SS Q 1 to SS Q 2 . The result shows that CSH gel structure does not change so much due to sodium or iodide ions, while Borrmann et al [10] …”

Section: Resultsmentioning

confidence: 87%

Some Experiments on Sorption Behavior of Iodide ions into CSH Gel under the Condition Saturated with Saline Groundwater

2012

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The main hydrate of cement is calcium silicate hydrate (CSH). Such a cement-based material is essential for constructing the geological disposal system of TRU radioactive wastes including I-129 in Japan. So far, the sorption behavior of iodine on CSH gel has been examined by using the CSH samples dried once. However, the Japan's repository would be constructed under water table. Therefore, we must focus on also the interaction of altered cementitious material and iodine under the condition saturated with saline groundwater.In this study, the sorption behavior of iodide ions into CSH gel, formed without dried processes, was examined in imitated saline groundwater. Ca/Si ratio was set to 0.4, 0.8, 1.2 and 1.6, and NaCl concentration of each sample also was set to 0.6 M, 0.06 M or 0.006 M. These samples were synthesized with CaO, SiO 2 (fumed silica), and distilled water in a given combination of 20 ml/g in liquid/solid ratio. A NaI solution was added after curing the CSH gel (hereinafter referred to as the "Surface sorption sample") for 7 days, setting the initial concentration of NaI to 0.5 mM in sample tube. The values of Eh and pH of each sample showed iodide ions as the chemical species of iodine in the sample tube. Furthermore, this study prepared the "Co-precipitation sample" of CSH gel with iodide ions. Here, the NaI solution was added before curing the CSH gel. For all samples, the contact time-period of the CSH gel with iodide ions was set to 7 days. After each contact time-period, each sample for analyses was separated into the solid and the liquid phases by 0.20 μm membrane filter. In the liquid phase, the concentrations of Ca, I, Si and Na ions in the liquid phase were measured by ICP-AES. Besides, the Raman spectra were obtained from the solid phases of the surface sorption sample and the co-precipitation sample without dried process.The results showed that the sorption of iodide ions into CSH gel strongly depends on the amount of water included in the CSH gel. Such a sorption behavior was confirmed in both coprecipitation samples and the surface sorption samples, even if the Ca/Si ratio is low. This means that iodide ions can be easily immobilized through the water-molecular of CSH gel. Besides, Na concentration did not so much affect the sorption behavior of iodide ions into CSH gel. In addition, the Raman spectra showed that the degree of polymerization of SiO 4 tetrahedrons in CSH gel was unaffected with increasing Na ions concentration. These results suggest that the CSH gel saturated with groundwater would retard the migration of iodide ions, even if the groundwater includes salinity.

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“…Figure 6 is the intensity ratio of SS Q 1 to SS Q 2 . The result shows that CSH gel structure does not change so much due to sodium or iodide ions, while Borrmann et al [10] …”

Section: Resultsmentioning

confidence: 87%

Some Experiments on Sorption Behavior of Iodide ions into CSH Gel under the Condition Saturated with Saline Groundwater

2012

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“…Iodination of organic molecules is one of the most basic reactions in organic chemistry. Iodine-containing compounds have been widely used in catalysis, agrochemicals, pharmaceuticals (Figure ), and materials science . In addition, iodides offer valuable opportunities for further functionalization, including many well-established transformations, such as nucleophilic substitution or cross-coupling reactions .…”

Section: Introductionmentioning

confidence: 99%

Electrochemical Synthesis of β-Iodoesters by 1,2-Iodoesterization of Unactivated Alkenes with Carboxylic Acids and Tetrabutylammonium Iodide

et al. 2023

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We report a novel and highly selective electrochemical method for the synthesis of β-iodoesters via difunctionalization of alkenes. The reaction is carried out in an undivided cell under constant current conditions without any additives, catalysts, oxidants, and sacrificial reagents. Inexpensive and readily available tetrabutylammonium iodide not only acts as an electrolyte but also serves as an iodine source. The reaction shows high selectivity and good functional group tolerance, providing products in yields of up to 98%. This method is applicable not only to the iodofunctionalization of alkenes but also to the chloro- and bromofunctionalization of alkenes. The successful modification of drugs and natural products demonstrates the potential utility of this approach.

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“…The iodination of organic molecules is one of the most fundamental reactions in organic chemistry, as iodine-containing molecules have found widespread applications in the fields of catalysis, − agrochemicals, pharmaceuticals, − and materials science . Moreover, iodide provides an invaluable opportunity for further functionalization with many well-established transformations, such as nucleophilic substitutions or cross-coupling reactions. , Therefore, the development of efficient methods for the construction of C–I bonds is highly desirable and sought after. − …”

Section: Introductionmentioning

confidence: 99%

Environmentally Friendly Protocol for the Oxidative Iodofunctionalization of Olefins in a Green Solvent

Wang

et al. 2019

ACS Sustainable Chem. Eng.

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An environmentally friendly iodofunctionalization of olefins for the synthesis of various iodinated products was developed via the oxidative umpolung of iodide using I 2 O 5 as the inorganic oxidant. The distinct advantages of this protocol over all previous methods include no generation of organic byproducts and the use of a green solvent, thus greatly reducing the environmental impact. Additionally, mild reaction conditions, good yields, and easy-to-operate features make the current reaction system a more attractive method for the synthesis of a variety of medicinal and agrochemical compounds of interest.

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Nano-structured calcium silicate hydrate functionalised with iodine

Cited by 10 publications

References 24 publications

Some Experiments on Sorption Behavior of Iodide ions into CSH Gel under the Condition Saturated with Saline Groundwater

Some Experiments on Sorption Behavior of Iodide ions into CSH Gel under the Condition Saturated with Saline Groundwater

Electrochemical Synthesis of β-Iodoesters by 1,2-Iodoesterization of Unactivated Alkenes with Carboxylic Acids and Tetrabutylammonium Iodide

Environmentally Friendly Protocol for the Oxidative Iodofunctionalization of Olefins in a Green Solvent

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