Mechanochromic Displays Based on Photoswitchable Cholesteric Liquid Crystal Elastomers

Autor(es)

de Castro, Lucas D. C. ; Lub, Johan ; Oliveira, Osvaldo N. ; Schenning, Albert P. H. J.

• Tipo de documento: Artigo Científico
• Fonte: ANGEWANDTE CHEMIE-INTERNATIONAL EDITION; v. N/A, p. 7-pg., 2024-10-22.

Resumo

Stimuli responsive optical materials are attractive for many areas, from healthcare to art design. However, creating intricate color-changing patterns for visual information is still a challenge. This work describes the preparation of mechanochromic structural colored intricate pictures imprinted in cholesteric liquid crystal elastomers by using a chiral isosorbide molecular photoswitch. The photoswitch contains a photoisomerizable cinnamate moiety and was incorporated in a main chain liquid crystal oligomer with photopolymerizable acrylate end groups. After coating, the structural colored film was irradiated with ultraviolet (UV) light in air causing E/Z isomerization of the cinnamate units leading to a redshift of the structural color of the film. A grayscale photomask was used to spatially control the photoisomerization reaction and imprint colorful pictures such as portraits and landscapes, in the cholesteric liquid crystal films with high resolution. Photopolymerization in a nitrogen atmosphere led to a mechanochromic cholesteric liquid crystal elastomer with striking structural colors that blueshift upon strain. The sharp details of the patterns were preserved even under deformation and the system returned to the initial state upon strain removal. Our work offers a simple photoswitch approach to prepare stimuli responsive optical polymers imprinted with color-changing pictures of unprecedented complexity. Mechanochromic intricate pictures with striking structural colors are imprinted in cholesteric liquid crystal elastomers by using a chiral isosorbide molecular photoswitch. image (AU)

• Processo FAPESP: 18/22214-6 - Rumo à convergência de tecnologias: de sensores e biossensores à visualização de informação e aprendizado de máquina para análise de dados em diagnóstico clínico
• Beneficiário: Osvaldo Novais de Oliveira Junior
• Modalidade de apoio: Auxílio à Pesquisa - Temático
• Processo FAPESP: 20/02938-0 - Padrões coloridos baseados em cristais fotônicos bioinspirados para aplicações mecanocromáticas
• Beneficiário: Lucas Daniel Chiba de Castro
• Modalidade de apoio: Bolsas no Brasil - Pós-Doutorado
• Processo FAPESP: 22/13385-7 - Sensores mecanocromáticos transferíveis tipo-estampa para monitoramento de mobilidade humana assistido por processamento de imagem com modelos de aprendizado de máquina
• Beneficiário: Lucas Daniel Chiba de Castro
• Modalidade de apoio: Bolsas no Exterior - Estágio de Pesquisa - Pós-Doutorado