title: pH-controlled self-assembling of meso-tetrakis(4-sulfonatophenyl)porphyrin-chitosan complexes.
abstract: Solid meso-tetrakis(4-sulfonatophenyl)porphyrin (TPPS(4))-chitosan supramolecular complexes were prepared by addition of porphyrin to an aqueous solution of chitosan at pH values. The precipitates obtained were assigned as 1 (pH 6.8) and 2 (pH 2.5) and characterized by spectroscopic, thermal, and microscopic methods. Spectroscopic investigation confirmed the presence of TPPS(4) and chitosan in both products and that the porphyrin is highly self-associated. H-type (stacked) of TPPS(4) aggregation was proposed for 1 and J-type (tilted) for 2. Thermal analysis revealed different pyrolysis routes of the complexes depending on their structural diversity. Light microscopic analysis indicated fibrous and lamellar microstructures, respectively, for 1 and 2. SEM and AFM analysis showed that both complexes consist of compact nanostructures; their size and interconnection is different for 1 and 2. Based on structural inferences, self-assembling hierarchy models were proposed for both of the TPPS(4)-chitosan supramolecular complexes.
authors.affiliation: Department of Analytical Chemistry, Institute of Chemical Technology, Prague 16628, Czech Republic. sinical@vscht.cz
authors.forename: Alla
authors.initials: A
authors.lastname: Synytsya
authors.forename: Andriy
authors.initials: A
authors.lastname: Synytsya
authors.forename: Petra
authors.initials: P
authors.lastname: Blafková
authors.forename: Jana
authors.initials: J
authors.lastname: Ederová
authors.forename: Jiri
authors.initials: J
authors.lastname: Spevacek
authors.forename: Petr
authors.initials: P
authors.lastname: Slepicka
authors.forename: Vladimír
authors.initials: V
authors.lastname: Král
authors.forename: Karel
authors.initials: K
authors.lastname: Volka
mesh_terms: D048271:Chitosan / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D009682:Magnetic Resonance Spectroscopy; D018625:Microscopy, Atomic Force; D015394:Molecular Structure; D049329:Nanostructures / Q000737:chemistry; D010316:Particle Size; D011166:Porphyrins / Q000737:chemistry*; D019265:Spectroscopy, Near-Infrared; D013499:Surface Properties; D013696:Temperature
chemical_list: D011166:Porphyrins; C092400:meso-tetrakis(4-sulfonatophenyl)porphyrin; D048271:Chitosan