Video Experimental Relacionado
Updated: Jul 12, 2026
09:09
Layer-by-layer Synthesis and Transfer of Freestanding Conjugated Microporous Polymer Nanomembranes
Published on: December 15, 2015
Una nueva membrana de carga-mosaico de un copolímero de varios bloques.
Science (New York, N.Y.)
|April 6, 1984
Resumen
Una nueva membrana de carga-mosaico separa selectivamente el cloruro de sodio de los compuestos orgánicos. Esta membrana exhibe una permeabilidad dependiente del pH para los aminoácidos, mostrando su potencial en tecnologías avanzadas de separación.
Área de la Ciencia:
- La ciencia de los polímeros es la ciencia de los polímeros.
- Ciencia de los materiales Ciencia de los materiales.
- Ciencia de la Separación Ciencia de la Separación
Sus antecedentes:
- Los copolímeros Pentablock ofrecen propiedades únicas de autoensamblaje para crear materiales nanoestructurados.
- El desarrollo de membranas selectivas es crucial para la separación eficiente de sales y moléculas orgánicas.
- Las membranas de carga-mosaico combinan propiedades de ambos materiales de intercambio catiónico y aniónico.
Objetivo del estudio:
- Para preparar una membrana de mosaico de carga a partir de un copolímero de pentabloque.
- Para investigar la permeabilidad de la membrana para el cloruro de sodio en presencia de especies orgánicas.
- Para evaluar la influencia del pH en la permeabilidad de los aminoácidos.
Principales métodos:
- Síntesis de un copolímero pentablock con una arquitectura BABCB.
- Introducción selectiva de grupos de intercambio aniónico y catiónico en fases microseparadas.
- Caracterización de la estructura lamelar de tres capas de la membrana.
- Estudios de permeabilidad utilizando soluciones acuosas mixtas de cloruro de sodio, especies orgánicas y aminoácidos.
Principales resultados:
- El proceso de modificación preservó la estructura lamelar de tres capas inicial de la película de copolímero pentablock.
- La membrana de carga-mosaico resultante demostró una alta permeabilidad exclusivamente para el cloruro de sodio cuando se mezcla con compuestos orgánicos de bajo peso molecular como la sacarosa.
- Se observó una permeabilidad significativa dependiente del pH para los aminoácidos, lo que indica propiedades de transporte sintonizables.
Conclusiones:
- Los copolímeros Pentablock se pueden funcionalizar de manera efectiva para crear membranas sofisticadas de carga-mosaico.
- La membrana desarrollada exhibe una excelente selectividad para la separación del cloruro de sodio de los solutos orgánicos.
- El transporte dependiente del pH de los aminoácidos pone de relieve el potencial para aplicaciones de separación y purificación controladas.
Videos de Conceptos Relacionados
01:19Fluid Mosaic Model
Scientists identified the plasma membrane in the 1890s and its principal chemical components (lipids and proteins) by 1915. The model for plasma membrane structure, proposed in 1935 by Hugh Davson and James Danielli, was the first model to be widely accepted in the scientific community. The model was based on the plasma membrane's "railroad track" appearance in early electron micrographs. Davson and Danielli theorized that the plasma membrane's structure resembled a sandwich with the analogy of...
01:34Fluid Mosaic Model
The fluid mosaic model was first proposed as a visual representation of research observations. The model comprises the composition and dynamics of membranes and serves as a foundation for future membrane-related studies. The model depicts the structure of the plasma membrane with a variety of components, which include phospholipids, proteins, and carbohydrates. These integral molecules are loosely bound, defining the cell’s border and providing fluidity for optimal function.LipidsThe most...
01:24Characteristics and Nomenclature of Copolymers
Copolymers are the products obtained from the polymerization of multiple monomer species. So, in a polymer chain itself, there can be multiple repeating units that come from different monomers. The process of synthesizing a polymer from different monomer species is called copolymerization. When two monomers are involved, the polymer is known as a bipolymer. Polymers with three and four monomers are termed terpolymers and quaterpolymers, respectively. Figure 1 depicts the copolymerization of...
01:54What are Membranes?
A key characteristic of life is the ability to separate the external environment from the internal space. To do this, cells have evolved semi-permeable membranes that regulate the passage of biological molecules. Additionally, the cell membrane defines a cell’s shape and interactions with the external environment. Eukaryotic cell membranes also serve to compartmentalize the internal space into organelles, including the endomembrane structures of the nucleus, endoplasmic reticulum and Golgi...
00:57Cationic Chain-Growth Polymerization: Mechanism
The cationic polymerization mechanism consists of three steps: initiation, propagation, and termination. In the initiation step of the polymerization process, the π bond of a monomer gets protonated by the Lewis acid catalyst, which is formed from boron trifluoride and water. The protonation of the π bond generates a carbocation stabilized by the electron‐donating group. In the propagation step, the π bond of the second monomer acts as a nucleophile and attacks the generated carbocation,...
01:17Ion Exchange
Ion exchange chromatography separates charged molecules from a solution by reversibly exchanging them with mobile, or 'active', ions associated with the oppositely charged stationary phase. This method can be used to separate ions, soften and deionize water, and purify solutions. The polymers comprising the ion-exchange column are high-molecular-weight and chemically stable polymers, crosslinked to be porous and essentially insoluble. They are also functionalized with either acidic or basic...