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Radiochemical Approach in Modification of Carbon Based Nanomaterials with Biopolymersтезисы доклада
- Авторы: Chernysheva M., Badun G.
- Сборник: Abstracts of Second International Conference of CIS IHSS on Humic Innovative Technologies «Natural and engineered nanoparticles in clean water and soil technologies»
- Том: 2
- Тезисы
- Год издания: 2012
- Место издания: Moscow, Russia
- Первая страница: 10
- Последняя страница: 10
- Аннотация: Non-covalent modification of carbon based nanomaterials with biopolymers is of fundamental importance to improve the profile of its technological and environmental application. Modern developments of chemistry of nanomaterials pointed us at the study of sorption ability of carbon-based nanomaterials to globular proteins and humic substances and to determine properties of formed complexes. Three types of carbon-based nanomaterials with different hydrophobic properties were under the test. They are graphene, single-walled carbon nanotubes and detonated nanodiamonds. The adsorption capacity carbon-based nanomaterials was studied in relation to brown coal humic acids (commercially available preparation Powhumus (Humintech, Germany)) and fulvic acids separated from Suwannee River (recommended as a standard by IHSS) and two globular proteins lysozyme from chicken egg white and human serum albumin (MP Biomedicals). Tritium label was used to determine or “trace” the amount of biopolymers adsorbed on solids. For this purpose tritium labeled humic substances and globular proteins were obtained by means of tritium thermal activation method [1, 2]. 5-12 mg sample of nanomaterial powder was placed in the Eppendorf tube followed by the addition of 0.8 ml of 3H-compound solution in phosphate buffer. The bulk radioactivity of compounds solutions was ca 55 MBq L-1. Ultrasonication of the dispersion was carried out for 2 hours using a bath sonicator (GRAD, Model 28-35, Russia) with rated power of 110 W followed by incubation at room temperature for 24 hours. The solutions thus obtained were subjected to centrifugation at 2400g (Vortex) for 60 min. The upper 75 % of the supernatant after ultracentrifugation was filtered through 13 mm syringe filter with 0.2 μm PVDF membrane (Acrodisc LC, Life Sciences). A sample of filtered solution was stirred in 7 ml of scintillation cocktail OptiPhase HiSafe 3 (PerkinElmer). Counting rate was measured by liquid scintillation spectrometer RackBeta 1215 (Finland). Adsorption Γ was calculated according to following equation Here I is counting rate, ε is registration efficiency of tritium β-radiation (from 40 to 50%), Va is volume of an aliquot, V = 0.8 ml, asp is specific radioactivity of the compound, c0 is initial concentration of the compound solution, m is mass of solids. Since radiotracer method was used adsorption isotherms were obtained in wide concentration range from 10 to 3000 mg L-1 for proteins and from 0.02 to 200 mg L-1 for humic substances. The values of the adsorption in plateau regions (in the cases of the Langmuir type adsorption isotherms) were about 0.5-1 g g-1 for proteins and reaches 40 g g-1 in the cases of humic substances. Besides determination of nanomaterial-conjugate composition, each nanomaterial-conjugate sample was subjected to dynamic light scattering analysis that allowed us to reveal the aggregation stability suspensions on nanomaterial-conjugate composition.
- Добавил в систему: Бадун Геннадий Александрович