Search results for "Supramolecular structure"
showing 7 items of 7 documents
Multi-scale structural analysis of xyloglucan colloidal dispersions and hydro-alcoholic gels
2020
Xyloglucans are highly branched, hydroxyl rich polyglucans that for their abundance in nature, biocompatibility, film forming and gelation ability may take a prominent role in the design and fabrication of biomedical devices, including in situ forming scaffolds for tissue engineering, wound dressings and epidermal sensors. The understanding and exploitation of their self-assembly behavior is key for the device performance optimization. A multi-scale analysis, conducted combining small-angle X-ray scattering, both static and dynamic light scattering at large and small angles, and rheological measurements, provides a description of the supramolecular organization of this biopolymer, from the …
Temperature-induced self-assembly of degalactosylated xyloglucan at low concentration
2015
Xyloglucan is a natural polysaccharide having a cellulose-like backbone and hydroxyl groups-rich side-chains. In its native form the polymer is water-soluble and forms gel only in presence of selected co-solutes. When a given fraction of galactosyl residues are removed by enzymatic reaction, the polymer acquires the ability to form a gel in aqueous solution at physiological temperatures, a property of great interest for biomedical/pharmaceutical applications. This work presents data on the effect of a temperature increase on degalactosylated xyloglucan dispersed in water at concentration low enough not to run into macroscopic gelation. Results obtained over a wide interval of length scales …
Self-Assembly-Directed Organization of a Fullerene–Bisporphyrin into Supramolecular Giant Donut Structures for Excited-State Charge Stabilization
2021
Functional materials composed of spontaneously self-assembled electron donor and acceptor entities capable of generating long-lived charge-separated states upon photoillumination are in great demand as they are key in building the next generation of light energy harvesting devices. However, creating such well-defined architectures is challenging due to the intricate molecular design, multistep synthesis, and issues associated in demonstrating long-lived electron transfer. In this study, we have accomplished these tasks and report the synthesis of a new fullerene–bis-Zn-porphyrin e-bisadduct by tether-directed functionalization of C60 via a multistep synthetic protocol. Supramolecular oligom…
Thermodynamics of cyclodextrin-star copolymer threading-dethreading process
2015
We investigated the interactions of a star-like copolymer with cyclodextrins (CD) with different cavity size. Direct measurements of thermodynamic properties were done, and the application of proper molecular models was useful for the interpretation of the involved phenomena. The CD–copolymer inclusion complexes were characterized by isothermal titration calorimetry. The copolymer aggregation induced by temperature was investigated by differential scanning calorimetry, volume and compressibility measurements. The behavior of the ternary T1107/CD/water mixture was interpreted considering competing equilibria. The investigated systems showed an interesting temperature responsive behavior so t…
Mixed aggregates based on tetronic-fluorinated surfactants for selective oils capture
2015
Abstract An aqueous star-like copolymer solution was titrated with perfluoro carboxylic acids at various compositions to prepare a polymeric surfactant composed of fluorinated nano-domains. The copolymer is X-shaped where each arm contains ethylene oxide and propylene oxide repetitive units linked to a central ethylenediamine group. The aggregation behavior of the hybrid macromolecule was studied from the physico-chemical point of view by changing parameters like temperature and composition. The solubilization of perfluorinated and hydrogenated alcohols in mixed self-assembled structure revealed that a selectivity toward the fluorinated moiety can be done. The self-assembled structures are …
Molecular, Supramolecular Structures Combined with Hirshfeld and DFT Studies of Centrosymmetric M(II)-azido {M=Ni(II), Fe(II) or Zn(II)} Complexes of…
2021
The supramolecular structures of the three metal (II) azido complexes [Fe(4bzpy)4(N3)2]
Crystallinity of block copolymer controlled by cyclodextrin
2018
We report a differential scanning calorimetry study to investigate the effect of cyclodextrins (CD) on the crystallinity of a copolymer. Tetronics was selected as copolymer with star-like shape formed by four polyethylene oxide flanked by four polypropylene oxide blocks linked to ethylenediamine central group. The use of CD with different cavity size was exploited for a block selective inclusion. A model for supramolecular association was considered for a quantitative description of the enthalpy data. The polymer chain incorporation into the CD cavity generates a loss of crystallinity. The stoichiometry of the CD/copolymer aggregates can be tuned by changing the CD cavity size. The investig…