We describe the preparation and characterization of a photonic crystal filled with a luminescent conjugated polyelectrolyte, sulfonated poly(phenylene ethynylene). The conjugated polymer was coated onto the nanospheres by the layer-by-layer method and assembled directly into a fluorescent opal structure avoiding the defects associated with post-filling schemes. These structures exhibit strong angle-dependent luminescent properties. By using multiple layers, we further demonstrate control over the emissive bands of the opal.
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http://dx.doi.org/10.1021/la046821p | DOI Listing |
Biomaterials
May 2025
Department of Chemistry, University of Massachusetts Amherst, 710 North Pleasant Street, Amherst, MA, 01003, USA. Electronic address:
Biofilm-associated infections arising from antibiotic-resistant bacteria pose a critical challenge to global health. We report the generation of a library of cationic conjugated poly(phenylene ethynylene) (PPE) polymers featuring trimethylammonium terminated sidechains with tunable hydrophobicity. Screening of the library identified an amphiphilic polymer with a C hydrophobic spacer as the polymer with the highest antimicrobial efficacy against biofilms in the dark with excellent selectivity.
View Article and Find Full Text PDFJ Chem Phys
March 2024
ICGM, Univ Montpellier, CNRS, ENSC, Montpellier, France.
The light-harvesting excitonic properties of poly(phenylene ethynylene) (PPE) extended dendrimers (tree-like π-conjugated macromolecules) involve a directional cascade of local excitation energy transfer (EET) processes occurring from the "leaves" (shortest branches) to the "trunk" (longest branch), which can be viewed from a vibronic perspective as a sequence of internal conversions occurring among a connected graph of nonadiabatically coupled locally excited electronic states via conical intersections. The smallest PPE building block that is able to exhibit EET, the asymmetrically meta-substituted PPE oligomer with one acetylenic bond on one side and two parallel ones on the other side (hence, 2-ring and 3-ring para-substituted pseudo-fragments), is a prototype and the focus of the present work. From linear-response time-dependent density functional theory electronic-structure calculations of the molecule as regards its first two nonadiabatically coupled, optically active, singlet excited states, we built a (1 + 2)-state-8-dimensional vibronic-coupling Hamiltonian model for running subsequent multiconfiguration time-dependent Hartree wavepacket relaxations and propagations, yielding both steady-state absorption and emission spectra as well as real-time dynamics.
View Article and Find Full Text PDFACS Appl Mater Interfaces
January 2024
Department of Chemistry, University of Texas, San Antonio, 1 UTSA Circle, San Antonio, Texas 78249, United States.
We report the light-activated antibacterial activity of a new class of phosphonium (R-PMe)-substituted conjugated polyelectrolytes (CPEs). These polyelectrolytes feature a poly(phenylene ethynylene) (PPE) conjugated backbone substituted with side groups with the structure -O-(CH)PMe, where = 3 or 6. The length of the side groups has an effect on the hydrophobic character of the CPEs and their propensity to interact with bacterial membranes.
View Article and Find Full Text PDFJ Chem Phys
March 2023
ICGM, Univ Montpellier, CNRS, ENSCM, Montpellier, France.
1,3-Bis(phenylethynyl)benzene is the primary chromophore of the light-harvesting polyphenylene ethynylene (PPE) dendrimers. It is experimentally known to share the same absorption spectrum as its pair of diphenylacetylene (aka. tolane) meta-substituted branches yet exhibits an unusual Stokes shift of about 2000 cm with respect to its band origin (corresponding to the loss of one vibrational quantum within the antisymmetric acetylenic stretching) in its emission spectrum.
View Article and Find Full Text PDFACS Appl Mater Interfaces
May 2022
Department of Chemistry, University of Texas at San Antonio, San Antonio, Texas 78249, United States.
Water-soluble conjugated polymers (WS-CPs) have found widespread use in bioapplications ranging from optical sensing to phototherapy. Modification of WS-CPs with specific molecular functional units is necessary to enable them to interact with biological targets. These targets include proteins, nucleic acids, antibodies, cells, and intracellular components.
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