Related Experiment Video
Updated: Jul 12, 2026
10:23
Self-assembly of Complex Two-dimensional Shapes from Single-stranded DNA Tiles
Published on: May 8, 2015
Cross-linked normal hexagonal and bicontinuous cubic assemblies via polymerizable gemini amphiphiles
Brad A Pindzola1, Jizhu Jin, Douglas L Gin
1Department of Chemistry, University of California, Berkeley, California 94720, USA.
Journal of the American Chemical Society
|March 6, 2003
Summary
Researchers developed novel polymerizable gemini surfactants that form stable liquid-crystalline phases. These intrinsically cross-linkable amphiphiles maintain their structure after photocross-linking, offering enhanced thermal stability.
Area of Science:
- Materials Science
- Supramolecular Chemistry
- Polymer Chemistry
Background:
- Gemini surfactants offer unique properties due to their dual hydrophobic tails and hydrophilic heads.
- Lyotropic liquid-crystalline (LLC) phases are ordered structures formed by amphiphiles in solution.
- Cross-linking amphiphiles can enhance the stability and properties of their mesophases.
Purpose of the Study:
- To synthesize and characterize intrinsically cross-linkable gemini surfactants.
- To investigate the lyotropic liquid-crystalline phase behavior of these novel amphiphiles.
- To explore the photocross-linking of these surfactants and the stability of the resulting materials.
Main Methods:
- Synthesis of bis(alkyl-1,3-diene)-based phosphonium gemini amphiphiles.
- Lyotropic liquid-crystalline phase behavior studies in water.
- Photocross-linking of LLC phases using UV-vis spectrometry.
- Powder X-ray diffraction for structural analysis.
- Thermal stability testing of cross-linked materials.
Main Results:
- The gemini surfactants formed hexagonal (H(I)), cubic (Q(I)), and lamellar (L(alpha)) phases.
- Photocross-linking retained the phase architecture of all observed LLC phases.
- Polymerization extent ranged from 23% to 71%, ensuring system stabilization.
- The cross-linked phases exhibited remarkable thermal stability up to 300°C in air.
Conclusions:
- These represent the first polymerizable gemini surfactants and the first cross-linkable amphiphiles polymerized in both hexagonal and cubic mesophases.
- The photocross-linking approach effectively stabilizes LLC microstructures.
- The resulting materials show significant potential for applications requiring high thermal stability.
Related Concept Videos
01:34Crossing Over
Unlike mitosis, meiosis aims for genetic diversity in its creation of haploid gametes. Dividing germ cells first begin this process in prophase I, where each chromosome—replicated in S phase—is now composed of two sister chromatids (identical copies) joined centrally.
The homologous pairs of sister chromosomes—one from the maternal and one from the paternal genome—then begin to align alongside each other lengthwise, matching corresponding DNA positions in a process called synapsis.
In order to...
The homologous pairs of sister chromosomes—one from the maternal and one from the paternal genome—then begin to align alongside each other lengthwise, matching corresponding DNA positions in a process called synapsis.
In order to...
02:11Conformations of Cyclohexane
Cyclohexane does not exist in a planar form due to the high angle and torsional strain it would experience in the planar structure. Instead, it adopts non-planar chair and boat conformations.
The chair form is the most stable and derives its name from its resemblance to the “easy chair.” In the chair conformation, two carbon atoms are arranged out-of-plane — one above and one below, minimizing the torsional strain. In the chair form, the bond angle is very close to the ideal tetrahedral value,...
The chair form is the most stable and derives its name from its resemblance to the “easy chair.” In the chair conformation, two carbon atoms are arranged out-of-plane — one above and one below, minimizing the torsional strain. In the chair form, the bond angle is very close to the ideal tetrahedral value,...
02:27Trihybrid Crosses
Trihybrid Crosses
Some of Mendel’s crosses examined three pairs of contrasting characteristics. Such a cross is called a trihybrid cross. A trihybrid cross is a combination of three individual monohybrid crosses. For example, plant height (tall vs. short), seed shape (round vs. wrinkled), and seed color (yellow vs. green).
The F1 generation plants of a trihybrid cross are heterozygous for all three traits and produce eight gametes. Upon self-fertilization, these gametes have an equal chance to...
Some of Mendel’s crosses examined three pairs of contrasting characteristics. Such a cross is called a trihybrid cross. A trihybrid cross is a combination of three individual monohybrid crosses. For example, plant height (tall vs. short), seed shape (round vs. wrinkled), and seed color (yellow vs. green).
The F1 generation plants of a trihybrid cross are heterozygous for all three traits and produce eight gametes. Upon self-fertilization, these gametes have an equal chance to...
01:25Space Trusses
A space truss is a three-dimensional counterpart of a planar truss. These structures consist of members connected at their ends, often utilizing ball-and-socket joints to create a stable and versatile framework. The space truss is widely used in various construction projects due to its adaptability and capacity to withstand complex loads.
At the core of a space truss lies the fundamental unit known as the tetrahedron. This structure is composed of six members that form a three-dimensional shape...
At the core of a space truss lies the fundamental unit known as the tetrahedron. This structure is composed of six members that form a three-dimensional shape...
01:07Symmetric Member in Bending
In the study of the mechanics of materials, analyzing the behavior of prismatic members under opposing couples is crucial for understanding internal stress distributions, which are essential for structural design. When subjected to couples, a prismatic member experiences internal forces that maintain equilibrium. A couple, characterized by two equal and opposite forces, creates a moment but no resultant force. The internal forces at any section cut of the member must balance these external...
01:21Plastic Deformations of Members with a Single Plane of Symmetry
When a structural member undergoes plastic deformation due to bending, it is crucial to understand the position of the neutral axis and the stress distribution. This member, characterized by a single plane of symmetry, exhibits a uniform stress distribution, with negative stress above the neutral axis and positive stress below. Notably, the neutral axis does not align with the centroid of the cross-section. This misalignment is typical in cases where the cross-section is not rectangular or...