Long alkyl groups are used in many functional polymers to improve their performance. The methylene sequences usually show a strong tendency to aggregate to form small alkyl nanodomains which can be either completely amorphous or partly crystalline. The influence of main chain packing, domain size, and density on the properties of self-assembled alkyl nanodomains is studied on the basis of a comparison of regiorandom and regioregular poly(3-alkylthiophenes) (P3ATs) with different side-chain length as model systems. We show that the dynamics of the CH(2) units in amorphous alkyl nanodomains is mainly independent of the packing of the main chains. Relaxation spectra show a similar CH(2) dynamics despite the fact that the thiophene main chains are crystalline in regioregular but amorphous in regiorandom P3ATs. The systematic dependence of the CH(2) dynamics on alkyl nanodomain size without clear change of the average volume per CH(2) unit underlines the importance of geometrical confinement. A competition of main- and side-chain crystallization mechanisms is discussed which should be considered if higher P3ATs are optimized for optoelectronic applications.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1021/jp1072999 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Intermolecular interaction mechanism for ionic liquids based on quaternary phosphonium cations with different symmetries using dielectric and spectroscopic analyses.
Phys Chem Chem Phys
January 2025
Department of Chemical Engineering, National Institute of Technology, Nara College, Yamatokoriyama, Nara 639-1080, Japan.
This study focuses on two types of phosphonium cation-based ionic liquids (P-ILs) with different alkyl chains: triethylalkylphosphonium (P222R) and tributylalkylphosphonium (P444R) cations. Broadband dielectric spectroscopy showed that the translational motion of the ions accelerated with an increasing number of alkyl chains by coupling with their rotational motion in both P-ILs. Raman spectroscopy revealed that P222R cations, despite dielectric similarities to P444R cations, can form all-trans conformations and cation-rich nanodomains because they have a relatively polar, short alkyl chain moiety with a central P atom and less-polar alkyl chains than those of P444R cations.
View Article and Find Full Text PDFStructural Reorganizations and Nanodomain Emergence in Lipid Membranes Driven by Ionic Liquids.
Langmuir
January 2025
Solid State Physics Division, Bhabha Atomic Research Centre, Mumbai 400085, India.
Article Synopsis
- Ionic liquids (ILs) show potential in pharmaceuticals and green chemistry, but their use is limited due to toxicity concerns from interactions with cell membranes.
- This study investigates imidazolium-based ILs' effects on a model cell membrane made of DPPC lipids, revealing that the shorter-chain IL, HMIM[Br], causes DPPC vesicle aggregation, while the longer-chain IL, DMIM[Br], creates IL-poor and IL-rich nanodomains instead.
- Findings indicate that the formation of membrane nanodomains correlates with increased membrane permeability and cytotoxicity of longer-chain ILs, providing insights for developing safer ILs for biomedical and industrial applications.
A large-strain and ultrahigh energy density dielectric elastomer for fast moving soft robot.
Nat Commun
May 2024
Key Lab of Organic Optoelectronics & Molecular Engineering, Department of Chemistry, Tsinghua University, 100084, Beijing, China.
Dielectric elastomer actuators (DEAs) with large actuation strain and high energy density are highly desirable for actuating soft robots. However, DEAs usually require high driving electric fields (>100 MV m) to achieve high performances due to the low dielectric constant and high stiffness of dielectric elastomers (DEs). Here, we introduce polar fluorinated groups and nanodomains aggregated by long alkyl side chains into DE design, simultaneously endowing DE with a high dielectric constant and desirable modulus.
View Article and Find Full Text PDFLiquid Structure of Ionic Liquids with [NTf] Anions, Derived from Neutron Scattering.
J Phys Chem B
April 2024
QUILL Research Centre, Queen's University Belfast, School of Chemistry and Chemical Engineering, David Keir Building, 39-123 Stranmillis Road, Belfast BT9 5AG, Belfast, U.K.
Article Synopsis
- Researchers investigated the liquid structure of three common ionic liquids (ILs) using neutron scattering for the first time, focusing on [NTf] anions and different cations like [Cmim] and [P].
- The study found larger nonpolar nanodomains in ILs as the alkyl chain length increased, and it provided insights into cation-anion interactions, specifically the hydrogen bonding dynamics.
- With the introduction of a new data analysis package called Dissolve, the research validated findings across different models and reported a modified synthesis method for a specific IL, setting the stage for further exploration of the phosphonium ILs using neutron scattering.
Trapping bond exchange phenomenon revealed for off-stoichiometry cross-linking of phase-separated vitrimer-like materials.
Soft Matter
March 2024
Department of Life Science and Applied Chemistry, Graduate School of Engineering, Nagoya Institute of Technology, Gokiso-cho Showa-ku, Nagoya-city, Aichi, 466-8555, Japan.
Vitrimer materials combined with nano-phase separated structures have attracted attention, expanding the tuning range of physical properties, such as flow and creep properties. We recently demonstrated a preparation of vitrimer-like materials with phase-separated nanodomains in which dissociative bond exchange -alkylation of quaternized pyridine was operated. In this study, we demonstrate a new finding about the bond exchange mechanism: that is, the trapping bond exchange phenomenon.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!