Synthesis of nanocomposite cryogels based on polyvinyl alcohol and carbon nanotubes
A. L. PYKIN1, N. N. BORISOVA2, S. I. ZHEREBTSOV1
1Federal Research Center for Coal and Coal Chemistry, Siberian Branch of the Russian Academy of Sciences, Kemerovo, Russia
2Research Institute of Complex Problems of Cardiovascular Diseases, Kemerovo, Russia
Keywords: cryogels, polyvinyl alcohol, carbon nanotubes, optimisation
Abstract
The high-strength nanocomposite cryogels based on polyvinyl alcohol (PVA) and carbon nanotubes (CNTs) have been synthesised and studied. To overcome the problems related to CNTs agglomeration in polar solvents, which limits their uniform distribution over the polymer matrix, cryogel composition was optimised to achieve high strength characteristics. To obtain uniform CNT dispersions, homogenisation in solvents (water, dimethyl sulphoxide (DMSO) and a mixture of DMSO/water = 80 : 20 by volume) in combination with ultrasonic treatment was used. During the experiment, cryogel samples were stretched uniaxially, which allowed us to obtain the ultimate strength values for each sample. Data processing was performed using STATISTICA 10 software. Using regression modelling, the Dependences between the ultimate strength of nanocomposites and synthesis parameters (the concentration of initial PVA solution, its molecular weight, water content in the solvent, and the concentration of CNTs) were established using regression modelling. The obtained regression equation was adequate with respect to Fisher’s criterion, and determination coefficient was R2 = 0.81, which confirms the accuracy of the model and its applicability for predicting the strength characteristics of cryogels. In addition to regression analysis, the dependences of the Harrington desirability function on synthesis parameters were analysed. This approach allowed us to identify optimal components ratio for obtaining PVA/CNT nanocomposite cryogels, which significantly increased the efficiency of developing materials with high strength properties. The results of the study emphasise the importance of taking into account various factors when optimising synthesis conditions and also offer new prospects for further research in the area of polymer composites.
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