Freeze-thawing plays a vital role in enhancing materials in medicines. Here, we describe the F-T process of synthesis of Poly (vinyl alcol)- Methylene blue single strand- Mxene (PVA–MB-ssDNA –Mxene), which may be effective for gen delivery applications. The PVA –MB-ssDNA –Mxene hydrogel was formed using 1,3,5 consecutive cycles. We also demonstrated that PVA –MB-ssDNA –Mxene hydrogel can be formed by the affection of DNA with PVA and the MXene network. The F-T process shows the new intra molecular bond of PVA-PVA, compared to the non F-T hydrogel which formed by a biologic crosslinking as MB-ssDNA. Scanning electron microscopy reported that the microstructure. The differential scan shows three endothermic peaks at 70, 180, and 300 ℃ for water loss and decomposition. The swelling behavior rapidly increased due to the PVA chains in the F-T methods and then became stable. With a high concentration of MB-DNA, the tensile strength was slightly high, and the swelling behavior was low. Our results indicated that the PVA –MB-ssDNA –Mxene hydrogel using F-T process would have more suitable structural features as gene hydrogel carrier which need greater mechanical strength and stability in body analyses.
The search for the development of nanostructured materials has led to the study of the properties of their precursors. For the production of nanofibers by the electrospinning process, it is necessary to determine the rheological parameters of the precursor solutions. Since these properties can be influenced by the processing variables and chemical composition of the polymer, this study aims to elucidate the effect of the addition of vinyl monomers in the formulation of nanofibers based on polyacrylonitrile and to determine the optimal parameters for the production of the precursor polymer solution. The effects of temperature and addition of vinyl monomers were evaluated by rheometry, from the analysis of the variation of the viscosity of the solutions, and by microscopy, the morphology of the nanofibers produced. It was observed that the increase in the temperature used to produce the solutions improves the fibers’ properties. Still, there is a relationship between the time of exposure of the polymeric solution to the temperature and the homogeneity of the fibers, which cannot exceed 45 min. The addition of vinyl monomers, to produce PAN-PVA co-polymeric fibers, increases the conductivity and reduces the viscosity of the solutions, resulting in more refined and homogeneous fibers.
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