Zobrazeno 1 - 10
of 26
pro vyhledávání: '"Bradley Frieberg"'
Publikováno v:
ACS macro letters. 2(5)
In thin film A/B polymer/polymer mixtures, the formation of a layer at the free surface, with average composition that differs from the bulk, due to the preferential segregation of the lower cohesive energy density component, is well understood. Whil
Publikováno v:
Macromolecules. 53:7684-7690
Upon quenching a polymer melt to a temperature T below its glass transition temperature Tg, structural relaxations, physical aging, enable the material to return to equilibrium. Whereas the physica...
Autor:
Emmanouil Glynos, Malvina Stathouraki, Georgios Sakellariou, Bradley Frieberg, Peter F. Green
Publikováno v:
Macromolecules. 50:3719-3725
Structural relaxations of a substance quenched to a temperature Tage below its glass transition temperature Tg enable the structure of the substance to approach equilibrium. This phenomenon, also known as physical aging, has been studied for many dec
Autor:
David W. Gidley, Bradley Frieberg, Alexandros Chremos, Emmanouil Glynos, Peter F. Green, Georgios Sakellariou
Publikováno v:
Macromolecules. 48:2305-2312
We show that the vitrification of star-shaped polystyrene (PS), of functionality f and molecular weight per arm Mwarm, thin films supported by silicon oxide, SiOx, is strongly dependent on Mwarm and f. When f is small, the vitrification behavior is s
Autor:
Suresh Narayanan, Emmanouil Glynos, Peter F. Green, Bradley Frieberg, Georgios Sakellariou, Alexandros Chremos, Kyle Johnson
Publikováno v:
Physical Review Letters. 119
The surface relaxation dynamics of supported star-shaped polymer thin films are shown to be slower than the bulk, persisting up to temperatures at least 50 K above the bulk glass transition temperature ${T}_{g}^{\mathrm{bulk}}$. This behavior, exhibi
Publikováno v:
Macromolecules. 47:1137-1143
The ability to control the wetting properties of a polymeric liquid on a given surface is important for several emerging technological applications including protective coatings, lubricants and sensors. Here we show that star-shaped polystyrene (PS)
Publikováno v:
ACS Nano. 8:607-613
Diverse processes that include energy conversion, wettability, lubrication, adhesion, and surface-directed phase separation in mixtures fundamentally depend on the structure and dynamics of materials' surfaces and interfaces. We report an unusual phe
Publikováno v:
ACS applied materialsinterfaces. 6(17)
Electrode buffer layers in polymer-based photovoltaic devices enable highly efficient devices. In the absence of buffer layers, we show that diode rectification is lost in ITO/P3HT:PCBM/Ag (ITO = indium tin oxide; P3HT = poly(3-hexylthiophene); PCBM
Publikováno v:
ACS applied materialsinterfaces. 4(10)
Regioregular poly(3-hexylthiophene) (RR-P3HT) is a widely used donor material for bulk heterojunction polymer solar cells. While much is known about the structure and properties of RR-P3HT films, important questions regarding hole mobilities in this
Publikováno v:
Physical review letters. 108(26)
Time-dependent changes of thermodynamic properties due to structural relaxations and physical aging occur in all glasses. We show that the physical aging of thin supported films of star-shaped macromolecules, with $f$ arms of length ${N}_{\mathrm{arm