title: Enhanced Alignment of Water-Soluble Polythiophene Using Cellulose Nanocrystals as a Liquid Crystal Template.
abstract: Cellulose nanocrystals (CNCs) are bioderived, rodlike particles that form a chiral nematic liquid crystal (LC) in water. In this work, CNCs were used to induce long-range order in a semiconducting polymer, poly[3-(potassium-4-butanoate) thiophene-2,5-diyl] (PPBT). When mixed with CNCs, it was found that PPBT was incorporated into the liquid crystal "template" to form ordered structures with highly birefringent domains, as observed under polarized light. We show that the π-π interactions between polymer chains, which contribute considerably to the energetics of the semiconducting system, are directly influenced by the presence and packing of the liquid crystal phase. Upon increasing the concentration of CNCs from the isotropic to chiral nematic regime, we observe a bathochromic shift in the UV-vis spectra and the emergence of the 0-0 vibrational peak, suggesting enhanced π-π stacking leading to chain coplanarization. Furthermore, the chiral nature of the PPBT/CNC mixture was evidenced by a negative peak in circular dichroism (CD) spectroscopy, promoting the notion that the polymer chains followed the helicoidal twist of the chiral nematic liquid crystal host. At high temperatures, the peak height ratios and overall intensities of the UV-vis and CD spectra associated with PPBT decreased as the chiral nematic pitch grew larger in size.
authors.affiliation: School of Chemical and Biomolecular Engineering, ‡School of Chemistry and Biochemistry, and §School of Materials Science and Engineering, Georgia Institute of Technology , Atlanta, Georgia 30332, United States.
authors.forename: Bailey E
authors.initials: BE
authors.lastname: Risteen
authors.affiliation: School of Chemical and Biomolecular Engineering, ‡School of Chemistry and Biochemistry, and §School of Materials Science and Engineering, Georgia Institute of Technology , Atlanta, Georgia 30332, United States.
authors.forename: Alyssa
authors.initials: A
authors.lastname: Blake
authors.affiliation: School of Chemical and Biomolecular Engineering, ‡School of Chemistry and Biochemistry, and §School of Materials Science and Engineering, Georgia Institute of Technology , Atlanta, Georgia 30332, United States.
authors.forename: Michael A
authors.initials: MA
authors.lastname: McBride
authors.affiliation: School of Chemical and Biomolecular Engineering, ‡School of Chemistry and Biochemistry, and §School of Materials Science and Engineering, Georgia Institute of Technology , Atlanta, Georgia 30332, United States.
authors.forename: Cornelia
authors.identifier: http://orcid.org/0000-0001-8687-7003
authors.initials: C
authors.lastname: Rosu
authors.affiliation: School of Chemical and Biomolecular Engineering, ‡School of Chemistry and Biochemistry, and §School of Materials Science and Engineering, Georgia Institute of Technology , Atlanta, Georgia 30332, United States.
authors.forename: Jung Ok
authors.initials: JO
authors.lastname: Park
authors.affiliation: School of Chemical and Biomolecular Engineering, ‡School of Chemistry and Biochemistry, and §School of Materials Science and Engineering, Georgia Institute of Technology , Atlanta, Georgia 30332, United States.
authors.forename: Mohan
authors.initials: M
authors.lastname: Srinivasarao
authors.affiliation: School of Chemical and Biomolecular Engineering, ‡School of Chemistry and Biochemistry, and §School of Materials Science and Engineering, Georgia Institute of Technology , Atlanta, Georgia 30332, United States.
authors.forename: Paul S
authors.initials: PS
authors.lastname: Russo
authors.affiliation: School of Chemical and Biomolecular Engineering, ‡School of Chemistry and Biochemistry, and §School of Materials Science and Engineering, Georgia Institute of Technology , Atlanta, Georgia 30332, United States.
authors.forename: Elsa
authors.identifier: http://orcid.org/0000-0002-8205-8016
authors.initials: E
authors.lastname: Reichmanis
mesh_terms: D002482:Cellulose / Q000031:analogs & derivatives*; D057927:Hydrophobic and Hydrophilic Interactions; D050866:Liquid Crystals / Q000737:chemistry*; D053758:Nanoparticles / Q000737:chemistry*; D011108:Polymers / Q000737:chemistry*; D012666:Semiconductors; D013876:Thiophenes / Q000737:chemistry*
chemical_list: D011108:Polymers; D013876:Thiophenes; C066730:polythiophene; D002482:Cellulose