Analyzing the Effects of Silica Nanospheres on the Sol-Gel Transition Profile of Thermosensitive Hydrogels

Autor(es)

Ribeiro, Lucas S. ^[1] ; Sala, Renata L. ^[1] ; de Jesus, Leticia A. O. ^[1] ; Cruz, Sandra A. ^[1] ; Camargo, Emerson R. ^[1]

Afiliação do(s) autor(es)

^[1] Fed Univ Sao Carlos UFSCar, Dept Chem, BR-13565905 Sao Carlos, SP - Brazil

• Tipo de documento: Artigo Científico
• Fonte: Langmuir; v. 37, n. 24, p. 7373-7379, JUN 22 2021.
• Citações Web of Science: 0

Resumo

The insertion of nanoparticles into smart hydrogels can diversify their functionalities by a synergistic combination of the components properties within the hydrogels. While these hybrid systems are attractive to the biomaterials field, careful design and control of their properties are required since the new interactions between the polymer and the nanoparticles can result in changes or the loss of hydrogels stimuli response. In order to understand the physicochemical aspects of the thermoresponsive systems, nanocomposites of poly(N-vinylcaprolactam) (PNVCL) and silica nanoparticles with different sizes and concentrations were synthesized. The UV-vis and DLS techniques showed that the PNVCL has a sharp phase transition at 34 degrees C, while the nanocomposites have a diffuse transition. The nanocomposites showed an initial coil- globule transition before the phase transition takes place. This was identified by the evolution of the hydrodynamic diameter of the nanocomposite globules before the cloud point temperature (T-cp), which remained constant for PNVCL. This new transition profile can be described by two stages in which microscopic volume transitions occur first, followed by the macroscopic transition that forms the hydrogel. These results show that the proposed nanocomposites can be designed to have tunable stimuli response to smaller temperature variations with the formation of intermediate globule states. (AU)

• Processo FAPESP: 13/25663-2 - Desenvolvimento de Nanocompósitos Poliméricos Aplicados em Engenharia Tecidual
• Beneficiário: Renata Lang Sala
• Modalidade de apoio: Bolsas no Brasil - Doutorado
• Processo FAPESP: 18/12871-0 - Modificação do perfil da temperatura de transição de nanocompósitos termossensíveis
• Beneficiário: Lucas da Silva Ribeiro
• Modalidade de apoio: Bolsas no Brasil - Doutorado Direto
• Processo FAPESP: 13/07296-2 - CDMF - Centro de Desenvolvimento de Materiais Funcionais
• Beneficiário: Elson Longo da Silva
• Modalidade de apoio: Auxílio à Pesquisa - Centros de Pesquisa, Inovação e Difusão - CEPIDs
• Processo FAPESP: 14/09014-7 - Estudo do potencial de nano-heteroestruturas de óxidos de cobre e nióbio para aplicação em fotossíntese artificial
• Beneficiário: André Esteves Nogueira
• Modalidade de apoio: Bolsas no Brasil - Pós-Doutorado