Related Experiment Video
Updated: Jul 30, 2025
15:33
Microwave-assisted Functionalization of Polyethylene glycol and On-resin Peptides for Use in Chain Polymerizations and Hydrogel Formation
Published on: October 29, 2013
29.1K
Polysaccharide-based polyampholyte complex formation: Investigating the role of intra-chain interactions
Ehsan Avazverdi1, Hamid Mirzadeh1, Morteza Ehsani2
1Polymer and Color Engineering Department, Amirkabir University of Technology, Tehran, Iran.
Carbohydrate Polymers
|May 14, 2023
Summary
Polyampholyte self-complexes exhibit greater ionic strength dependence than polyelectrolyte complexes. Intra-chain attractions in polyampholytes reduce chain expansion, impacting electrostatic complex properties.
Area of Science:
- Polymer Science
- Electrochemistry
- Materials Science
Background:
- Polyelectrolytes and polyampholytes are crucial in forming electrostatic complexes.
- Understanding inter-chain vs. intra-chain electrostatic interactions is key to complex behavior.
Purpose of the Study:
- Investigate electrostatic complex formation differences between polyelectrolytes and polyampholytes.
- Analyze the impact of intra-chain vs. inter-chain electrostatic attractions on complex properties.
- Characterize carboxymethyl chitosan (CMCh) self-complex behavior.
Main Methods:
- Utilized turbidimetric, water content, and rheological measurements.
- Applied the Katchalsky-Lifson model to potentiometric data for parameter calculation.
- Studied gyration radii as a function of Debye length.
Main Results:
- Polyampholyte self-complexes showed higher ionic strength dependence compared to polyelectrolyte complexes.
- Observed polyampholyte chain contraction due to intra-chain electrostatic attractions.
- Calculated reduced intrinsic and electrostatic persistence length for polyampholytes.
Conclusions:
- Intra-chain attractions in polyampholytes influence electrostatic complex formation and properties.
- Carboxymethyl chitosan (CMCh) exhibits distinct behavior compared to chitosan (Ch) and carboxymethyl cellulose (CMCe).
- The study provides deeper insights into CMCh behavior and its electrostatic complexes.
Related Concept Videos
00:57Cationic Chain-Growth Polymerization: Mechanism
2.4K
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...
2.4K
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
01:04Anionic Chain-Growth Polymerization: Mechanism
2.1K
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...
2.1K
02:34Polymers
35.9K
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...
35.9K
01:03Step-Growth Polymerization: Overview
3.6K
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...
3.6K
01:14Polymer Classification: Architecture
2.8K
Polymers are classified as linear or branched on the basis of their chain architecture. The polymer chains in linear polymers have a long chain-like structure with minimal to no branching at all. Even if a polymer features large substituent groups on the monomer, which appear as branches to the skeleton, it is not considered a branched polymer. A branched polymer contains secondary polymer chains that arise from the main polymer chain. The branching occurs when the polymer growth shifts from...
2.8K