Related Experiment Video
Updated: Feb 7, 2026
07:28
Evolution of Staircase Structures in Diffusive Convection
Published on: September 5, 2018
6.9K
Dynamic Evolution from Chain Disorder to Order of PTB7 Condensed State Structures under External Fields
Jiaxuan Ren1, Xiaona Li1, Tengning Ma1
1State Key Laboratory of Supramolecular Structure and Materials, College of Chemistry , Jilin University , No. 2699 Qianjin Avenue , Changchun 130012 , China.
ACS Applied Materials & Interfaces
|July 31, 2018
Summary
External fields like solvent, temperature, concentration, and force influence the order of poly[[4,8-bis[(2-ethylhexyl)oxy]benzo[1,2- b:4,5- b]dithiophene-2,6-diyl][3-fluoro-2-[(2-ethylhexyl)carbonyl]thieno[3,4- b]thiophenediyl]] (PTB7) structures. This impacts condensed state structures and optical properties for devices.
Area of Science:
- Materials Science
- Condensed Matter Physics
- Polymer Chemistry
Background:
- The performance of organic electronic devices relies heavily on the condensed state structures of conjugated polymers.
- Controlling the transition from amorphous to ordered states in polymers like PTB7 is crucial for optimizing material properties.
- Understanding the influence of external fields on polymer morphology is essential for material design.
Purpose of the Study:
- To investigate the effect of external fields (solvent, temperature, concentration, force) on the dynamic evolution of PTB7 condensed state structures.
- To correlate structural changes with optical properties using UV-vis absorption spectra and microscopy techniques.
- To provide a physical basis for designing conjugated polymers with enhanced photoelectronic device efficiency.
Main Methods:
- Utilized UV-vis absorption spectroscopy to analyze changes in PTB7 electronic transitions.
- Employed atomic force microscopy (AFM) and transmission electron microscopy (TEM) to visualize morphological changes.
- Varied external conditions including solvent type (1,2-dichloroethane), temperature, solution concentration, and applied force.
Main Results:
- Poor solvent (1,2-dichloroethane) induced amorphous PTB7 conformations.
- Reduced temperature, decreased solution concentration, or increased external force promoted the formation of ordered PTB7 aggregates.
- The ratio of absorption peaks (A0-0/A0-1) increased from 0.94 (amorphous) to 1.25 (large-ordered aggregation), indicating increased order.
Conclusions:
- External fields significantly control the transition from disordered to ordered states in PTB7 condensed structures.
- The observed structural evolution (amorphous, local aggregation, large-scale aggregation) can be monitored via optical and microscopic methods.
- This research offers fundamental insights into polymer self-assembly, vital for tailoring materials for high-performance photoelectronic devices.
Related Concept Videos
02:55The Evidence for Evolution
48.3K
Genetic variations accumulating within populations over generations give rise to biological evolution. Evolutionary changes can result in the formation of novel varieties and entire new species. These changes are responsible for the diverse forms of life inhabiting the planet. The evidence for evolution suggests that all living organisms descended from common ancestors.
48.3K
02:18Intrinsically Disordered Proteins
19.6K
Intrinsically disordered proteins are a group of proteins that do not fold into specific three-dimensional structures. Their structural flexibility allows them to complement ordered proteins to perform functions that are inaccessible to rigid structures. They are more common in eukaryotes than prokaryotes and may either be exclusively intrinsically disordered or hybrid proteins, consisting of a mix of ordered and disordered regions. The absence of a rigid structure in these proteins can be...
19.6K
01:54Convergent Evolution
33.0K
Evolution shapes the features of organisms over time, ensuring that they are suited for the environments in which they live. Sometimes, selection pressure leads to the rise of similar but unrelated adaptations in organisms with no recent common ancestors, a process known as convergent evolution.
33.0K
02:39Phase Transitions: Vaporization and Condensation
21.5K
The physical form of a substance changes on changing its temperature. For example, raising the temperature of a liquid causes the liquid to vaporize (convert into vapor). The process is called vaporization—a surface phenomenon. Vaporization occurs when the thermal motion of the molecules overcome the intermolecular forces, and the molecules (at the surface) escape into the gaseous state. When a liquid vaporizes in a closed container, gas molecules cannot escape. As these gas phase molecules...
21.5K
01:33Aldol Condensation vs Claisen Condensation
7.9K
Aldol condensation is an acid or base-catalyzed condensation between aldehydes or ketones to give an α,ꞵ-unsaturated carbonyl compound. A base-promoted condensation between ester molecules to produce a ꞵ-ketoester is known as the Claisen condensation. In the presence of a base, both reactions involve deprotonation of the acidic α hydrogen to produce the corresponding enolates. The nucleophilic enolates attack their respective nonenolized carbonyl compound forming a tetrahedral...
7.9K
01:28Electron Transport Chains
112.4K
The final stage of cellular respiration is oxidative phosphorylation that consists of two steps: the electron transport chain and chemiosmosis. The electron transport chain is a set of proteins found in the inner mitochondrial membrane in eukaryotic cells. Its primary function is to establish a proton gradient that can be used during chemiosmosis to produce ATP and generate electron carriers, such as NAD+ and FAD, that are used in glycolysis and the citric acid cycle.
The ETC is comprised of...
The ETC is comprised of...
112.4K