Video Experimental Relacionado
Updated: Jul 16, 2025
09:37
Fabrication of a Bioactive, PCL-based "Self-fitting" Shape Memory Polymer Scaffold
Published on: October 23, 2015
12.7K
Polímero de memoria de forma con inicio de recuperación programable
1State Key Laboratory of Chemical Engineering, College of Chemical and Biological Engineering, Zhejiang University, Hangzhou, China.
Nature
|September 13, 2023
Resumen
Este estudio presenta un nuevo hidrogel de cambio de forma que responde a la temperatura natural del cuerpo. Ofrece un retraso programable para la recuperación de la forma, superando las limitaciones de los polímeros de cambio de forma actuales para dispositivos médicos.
Área de la Ciencia:
- Ciencias de los materiales
- Química de los polímeros
- Ingeniería biomédica
Sus antecedentes:
- Los polímeros que cambian de forma y responden a estímulos son cruciales para aplicaciones avanzadas como la robótica blanda y los dispositivos médicos.
- Los desencadenantes externos (calor, luz) para los polímeros que cambian de forma presentan desafíos significativos en escenarios del mundo real, especialmente para los dispositivos implantables.
- Los polímeros existentes requieren disparadores externos o carecen de control sobre el inicio de la recuperación cuando se usan estímulos naturales.
Objetivo del estudio:
- Desarrollar un polímero de cambio de forma que se activa de forma natural pero que se puede controlar activamente.
- Para superar los atributos contradictorios del desencadenamiento natural y el inicio de la recuperación controlable en polímeros de memoria de forma.
- Crear un material que reduzca las barreras de implementación para aplicaciones de dispositivos avanzados.
Principales métodos:
- Desarrolló un hidrogel de memoria de forma imprimible en cuatro dimensiones utilizando la separación de fases.
- Investigada cinética de cambio de forma dominada por la difusión de masa interna, distinta del transporte de calor en polímeros convencionales.
- Diseñado un retraso de inicio de recuperación programable mediante el control del grado de separación de fase durante la programación del dispositivo.
Principales resultados:
- El hidrogel exhibe transformación de forma a las temperaturas ambientales naturales.
- Se logró un retraso programable crítico en el inicio de la recuperación, controlado por el grado de separación de fase.
- La cinética está regida por la difusión de masa interna, ofreciendo un nuevo mecanismo de control.
Conclusiones:
- Este polímero de memoria de forma activado naturalmente con un inicio de recuperación ajustable reduce significativamente las barreras de implementación.
- El material ofrece una solución única para el control de cambio de forma bajo demanda en aplicaciones exigentes.
- La separación de fases y la difusión de masa interna proporcionan una nueva vía para el diseño de materiales avanzados de cambio de forma.
Videos de Conceptos Relacionados
01:03Step-Growth Polymerization: Overview
3.5K
Step-growth or condensation polymerization is a stepwise reaction of bi or multifunctional monomers to form long-chain polymers. As all the monomers are reactive, most of the monomers are consumed at the early stages of the reaction to form small chains of reactive oligomers, which then combine to form long polymer chains in the late stages. Hence, the reaction has to proceed for a long time to achieve high molecular weight polymers.
Many natural and synthetic polymers are produced by...
Many natural and synthetic polymers are produced by...
3.5K
01:08Molecular Weight of Step-Growth Polymers
2.2K
Step growth polymerization involves bi or multifunctional monomers. Bifunctional monomers react to form linear step growth polymers, whereas multifunctional monomers react to form non-linear or branched polymers.
As the step-growth polymerization involves step-wise condensation of monomers, the molecular weight also builds up eventually. Consequently, high molecular weight polymers are obtained at the late stages of the polymerization, where 99% of monomers have been consumed.
The extent of the...
As the step-growth polymerization involves step-wise condensation of monomers, the molecular weight also builds up eventually. Consequently, high molecular weight polymers are obtained at the late stages of the polymerization, where 99% of monomers have been consumed.
The extent of the...
2.2K
01:20Types of Step-Growth Polymers: Polyesters
2.3K
The introduction of polyesters has brought major development to the textile industry. The wrinkle-free behavior of polyester blends has eliminated the need for starching and ironing clothes.
Polyesters are commonly prepared from terephthalic acid and ethylene glycol; the crude product is known as poly(ethylene terephthalate) or PET. However, polyesters are synthesized industrially by transesterification of dimethyl terephthalate with ethylene glycol at 150 °C. The two reactants and the...
Polyesters are commonly prepared from terephthalic acid and ethylene glycol; the crude product is known as poly(ethylene terephthalate) or PET. However, polyesters are synthesized industrially by transesterification of dimethyl terephthalate with ethylene glycol at 150 °C. The two reactants and the...
2.3K
01:21Plastic Behavior
219
A material's elastic behavior is characterized by the disappearance of stress once the load is removed, allowing the material to return to its original state. However, when stress surpasses the yield point, yielding commences, marking the onset of plastic deformation or permanent set. This change from elastic to plastic behavior is influenced by the peak stress value and the duration before the load is removed. An intriguing observation occurs when a specimen is loaded, unloaded, and...
219
01:21Polymer Classification: Crystallinity
2.9K
Unlike ionic or small covalent molecules, polymers do not form crystalline solids due to the diffusion limitations of their long-chain structures. However, polymers contain microscopic crystalline domains separated by amorphous domains.
Crystalline domains are the regions where polymer chains are aligned in an orderly manner and held together in proximity by intermolecular forces. For example, chains in the crystalline domains of polyethylene and nylon are bound together by van der Waals...
Crystalline domains are the regions where polymer chains are aligned in an orderly manner and held together in proximity by intermolecular forces. For example, chains in the crystalline domains of polyethylene and nylon are bound together by van der Waals...
2.9K
01:20Anionic Chain-Growth Polymerization: Overview
2.1K
The polymerization process that involves carbanion as an intermediate is called anionic polymerization. It is also a type of addition or chain-growth polymerization. Anionic polymerization gets initiated by a strong nucleophile such as an organolithium or a Grignard reagent. The most commonly used initiator for anionic polymerization is butyl lithium. Monomers involved in anionic polymerization must possess a vinyl group bonded to one or two electron-withdrawing groups. For instance,...
2.1K