Comb-like Polymethacrylates Research Articles

Remote hydrogelation by metal-ligand coordination using high intensity focused ultrasound

Smart materials have garnered interest due to their potential and versatility in a wide range of applications from tissue engineering, drug delivery, and cosmetics. It should be appreciated that while ultrasound has been utilized as a stimulus for smart materials, including organogels, its application has primarily been focussed below 100 kHz and for chemical scission. To investigate the potential of high intensity focussed ultrasound (HIFU) for gel formation, we synthesized a water-soluble comb-like polymethacrylate copolymer with randomly distributed tridentate ligands. We utilized reversible metal-ion non-covalent interactions in the design of our polymeric system to bind monomeric units together into temporary crosslinking networks or polymeric aggregates. To minimize the immediate formation of the metallogel, other functional groups within the polymer were involved in competitive reversible binding processes with the solvated metal ions. We show that HIFU triggers hydro-metallogelation by breaking the weaker labile interactions that in turn may allow for more favourable metal ion-ligand chelation, resulting in the formation of a gel network. Considering the established targeting potential of HIFU, our results here open a framework for targeted in situ triggered acoustic hydro-metallogelation for biomedical and industrial applications.

Synthesis and Conduction Mechanism of Comb-like Polymethacrylate Solid Polymer Electrolytes

Synthesis and Conduction Mechanism of Comb-like Polymethacrylate Solid Polymer Electrolytes

Comblike Polymethacrylates with Poly(ethylene glycol) Side Chains via Nitroxide-Mediated Controlled Free-Radical Polymerization

ADVERTISEMENT RETURN TO ISSUEPREVCommunication to the...Communication to the EditorNEXTComblike Polymethacrylates with Poly(ethylene glycol) Side Chains via Nitroxide-Mediated Controlled Free-Radical PolymerizationJulien Nicolas*†, Patrick Couvreur†, and Bernadette Charleux‡View Author Information Laboratoire de Physico-Chimie, Pharmacotechnie et Biopharmacie, UMR CNRS 8612, Faculté de Pharmacie, Univ. Paris-Sud, 5 rue Jean-Baptiste Clément, FR 92296 Châtenay-Malabry, France, and Laboratoire de Chimie des Polymères, UMR CNRS 7610, UPMC Paris 6, 4 place Jussieu, FR 75252 Paris cedex 05, France* Corresponding author: Tel +33 1 46 83 58 53 ; fax +33 1 46 61 93 34; e-mail [email protected]†Univ. Paris-Sud.‡UPMC Paris 6.Cite this: Macromolecules 2008, 41, 11, 3758–3761Publication Date (Web):May 8, 2008Publication History Received19 March 2008Revised14 April 2008Published online8 May 2008Published inissue 1 June 2008https://doi.org/10.1021/ma800609bCopyright © 2008 American Chemical SocietyRIGHTS & PERMISSIONSArticle Views893Altmetric-Citations58LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit Read OnlinePDF (583 KB) Get e-AlertsSupporting Info (1)»Supporting Information Supporting Information SUBJECTS:Ethanol,Monomers,Organic compounds,Polymerization,Styrenes Get e-Alerts

A cylindrical polymer: a stack of discotic triphenylene within comblike polymethacrylate.

This gently glowing tube: A cylindrical polymer, consisting of a stack of discotic triphenylene molecules enveloped in comblike polymethacrylate, self-assembles into hexagonal columns which then aggregate into nanorods (see graphic). This hierarchically organized material exhibits remarkable photophysical properties, including an unusually high fluorescence yield over a wide absorbance range.

Temperature Dependence of the Conformation of a Comblike Liquid Crystalline Polymer in a NI Nematic Phase

The backbone conformation of a comblike polymethacrylate, PMA-CH3, was studied by small-angle neutron scattering in the nematic phase. The backbone is perpendicular to the mesogenic side chain moieties, corresponding to the oblate ellipsoid of the NI phase of Wang and Warner's theory. We have measured the temperature dependence of the conformation of the polymer backbone on five well-defined molecular weights. In the direction perpendicular to the hanging groups, the backbone adopts a weakly confined random walk conformation, compared to that of the isotropic phase. In the direction of the nematic field, the chain conformation is extended: the exponents of the scaling laws vary between 0.60 and 0.50. At low temperature, smectic fluctuations freeze the backbone anisotropy. When increasing the temperature, the nematic order exerts a weaker force on the polymer backbone, which tends to an isotropic Gaussian conformation. The scaling laws for the backbone conformation and their variations with temperature are compared to the theoretical predictions.

Effect of the Molecular Weight on the Whole Conformation of a Liquid Crystalline Comb-like Polymer in Its Melt

The whole conformation of a comb-like polymethacrylate (PMA-CH3) has been determined by small-angle neutron scattering (SANS) in the isotropic and nematic phases. Its molecular weight dependence is...

Influence of the Mesophase Structure on the .beta.-Relaxation in Comb-like Polymethacrylates

Broad-band dielectric spectroscopy in the frequency range from 10 -2 to 10 6 Hz and in a temperature range from 170 to 430 K is employed to study the dependence of the rotation of the mesogenic unit around its long axis (β-relaxation) on the actual liquid crystalline mesophase in comb-like polymethacrylates. As mesogenic units, derivatives of p-alkoxyphenyl benzoate are used where different mesophases were achieved by small variation of the mesogenic structure and the spacer length. For all samples, the temperature dependence of the relaxation rate of β-relaxation can be described by an Arrhenius equation whereas both the preexponential factor and the activation energy increase significantly with the order of the mesophase. The width of the dielectric β-peak decreases with increasing order of the liquid crystalline phase. From these experimental results it is concluded that β-relaxation in these polymers is a cooperative relaxation process whereas the cooperativity increases with the order of the mesophase.