Related Experiment Video
Updated: Jun 26, 2026
09:22
Self-assembling Morphologies Obtained from Helical Polycarbodiimide Copolymers and Their Triazole Derivatives
Published on: February 7, 2017
Aggregation of conjugated polymers in aromatic solvent.
M Habibur Rahman1, Shao-Ching Liao, Hsin-Lung Chen
1Department of Chemical Engineering, National Tsing Hua University, Hsinchu 30013, Taiwan.
Langmuir : the ACS Journal of Surfaces and Colloids
|January 3, 2009
Summary
Conjugated polymer aggregation in toluene is stabilized by polymer-solvent complexes. Solvent molecules get trapped, revealing polymer segment alignment via NMR.
Area of Science:
- Polymer Science
- Organic Chemistry
- Materials Science
Background:
- Conjugated polymers often aggregate in organic solvents.
- Understanding aggregation is key for polymer applications.
Purpose of the Study:
- To investigate the mechanism of segmental aggregation in poly(9,9-bis(2-ethylhexyl)fluorene-2,7-diyl) (PF2/6) in toluene.
- To elucidate the role of polymer-solvent interactions in stabilizing these aggregates.
Main Methods:
- Nuclear Magnetic Resonance (NMR) spectroscopy to analyze polymer-solvent interactions.
- Variable temperature studies to observe aggregation dynamics.
Main Results:
- Segmental aggregation of PF2/6 in toluene is stabilized by polymer-solvent complex formation.
- Solvent molecules (toluene) are trapped within aggregate domains at subambient temperatures.
- NMR reveals alignment of polymer segments within aggregates due to strong polymer-solvent complexation.
Conclusions:
- Polymer-solvent complexation, involving pi-pi stacking, plays a crucial role in stabilizing conjugated polymer aggregates.
- Trapped solvent molecules provide insights into the ordered structure of polymer aggregates.
- The findings offer a deeper understanding of aggregation phenomena in conjugated polymers.
Related Concept Videos
02:34Polymers
The word polymer is derived from the Greek words “poly” which means “many” and “mer” which means “parts”. Polymers are long chains of molecules composed of repeating units of smaller molecules, known as monomers. They either occur naturally, such as DNA and proteins, or can be constructed synthetically, like plastics. They have varied structural characteristics, such as linear chains, branched chains, or complex networks, that contribute to the properties that they exhibit. Additionally,...
00:53Olefin Metathesis Polymerization: Acyclic Diene Metathesis (ADMET)
Acyclic diene metathesis polymerization or ADMET polymerization involves cross-metathesis of terminal dienes, such as 1,8-nonadiene, to give linear unsaturated polymer and ethylene. As ADMET is a reversible process, the formed ethylene gas must be removed from the reaction mixture to complete the polymerization process.
Similar to cross-metathesis, ADMET also involves the formation of metallacyclobutane intermediate by [2+2] cycloaddition of one of the double bonds of a terminal diene with...
Similar to cross-metathesis, ADMET also involves the formation of metallacyclobutane intermediate by [2+2] cycloaddition of one of the double bonds of a terminal diene with...
01:03Step-Growth Polymerization: Overview
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...
01:20Anionic Chain-Growth Polymerization: Overview
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,...
01:04Anionic Chain-Growth Polymerization: Mechanism
The mechanism for anionic chain-growth polymerization involves initiation, propagation, and termination steps. In the initiation step, a nucleophilic anion, such as butyl lithium, initiates the polymerization process by attacking the π bond of the vinylic monomer. As a result, a carbanion, stabilized by the electron‐withdrawing group, is generated. The resulting carbanion acts as a Michael donor in the propagation step and attacks the second vinylic monomer, which acts as a Michael acceptor.
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,...