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Showing 2 results for Agbolaghi

S. Agbolaghi,
Volume 17, Issue 2 (June 2020)
Abstract

Confined and unconfined crystallizations of poly(3-hexylthiophene) (P3HT) were studied in the solution-grown supramolecules and melt-grown systems using a differential scanning calorimeter. The carbon nanotube (CNT) and reduced graphene oxide (rGO) and their functionalized (CNT-f-COOTh and rGO-f-TAA) and grafted (CNT-g-PDDT and rGO-g-PDDT) derivatives were employed to develop the samples. The absorbance, structure details via Scherrer formula, fusion enthalpy (ΔHm) and crystallinity (Xc) were measured in two distinct confined/unconfined crystallization environments. Although the functionalized-CNT/rGO precursors partially reduced the crystallite qualities with respect to the pristine CNT and rGO ones in the solution-grown supramolecules, they did not affect the structural properties in the melt-grown samples. Grafted carbonic materials could be considered as appropriate seeds for the arrangement of P3HTs in both solution and melt crystallizations. The best absorbances, larger and more compact crystals, and higher melting point, ΔHm, and Xc values were recorded for the pre-developed CNT-g-PDDT/P3HT stem-leaf (6.09–22.51 nm, 3.52–13.89 Å, 239.8 °C, 30.86 J/g and 83.40%) and rGO-g-PDDT/P3HT coarse-patched (5.96–20.76 nm, 3.57–13.95 Å, 237.6 °C, 29.13 J/g and 78.73%) supramolecules. Although the melt-grown CNT-g-PDDT/P3HT (201.4 °C, 215.3 °C, 16.22 J/g and 43.84%) and rGO-g-PDDT/P3HT (205.4 °C, 218.8 °C, 18.06 J/g and 48.81%) nanostructures were not as perfect as the respective solution-grown nano-hybrids, they were well-arranged with respect to the CNT/P3HT, CNT-f-COOTh/P3HT, rGO/P3HT and rGO-f-TAA/P3HT samples

Saleheh Abbaspoor, Farhang Abbasi, Samira Agbolaghi,
Volume 19, Issue 2 (June-Biomaterials Special Issue- 2022)
Abstract

Single crystals of double crystalline block copolymers of poly(ethylene glycol) (PEG)-b-poly(ε-caprolactone) (PCL) and PEG-b-poly(L-lactide) (PLLA) were grown from dilute solution in homo- and mixed-brush systems. Crystallization behavior of biodegradable one end-restricted crystallizable PCL and PLLA chains in homo- and mixed-brush nanostructures were investigated. Chemical and physical circumstances of crystallizable brushes were altered. Physical environment was adjusted by amorphism/crystallinity and rigidity/flexibility of neighboring brushes. Chemical environment was manipulated by interaction and miscibility of various brushes. Distinct single crystals were grown with mixed-brushes of amorphous-crystalline (polystyrene (PS), poly(methyl methacrylate) (PMMA), PCL and PLLA, double crystalline (PCL/PLLA), and rod-crystalline polyaniline (PANI)/PCL or PLLA. Surrounding was only effective on hindrance or nucleation commencement of crystallization for crystallizable brushes and had no effect on crystallization features. Novel three-layer fully single crystalline nanostructures, whose characteristics were fixed via changing the crystallization temperature, were also developed. For long crystallizable tethers, crystallization increased both brush and substrate thicknesses. 

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