First-principles study of the effect of functional groups on polyaniline backbone

We present a first-principles density functional theory study focused on how the chemical and electronic properties of polyaniline are adjusted by introducing suitable substituents on a polymer backbone. Analyses of the obtained energy barriers, reaction energies and minimum energy paths indicate that the chemical reactivity of the polyaniline derivatives is significantly enhanced by protonic acid doping of the substituted materials. Further study of the density of states at the Fermi level, band gap, HOMO and LUMO shows that both the unprotonated and protonated states of these polyanilines are altered to different degrees depending on the functional group. We also note that changes in both the chemical and electronic properties are very sensitive to the polarity and size of the functional group. It is worth noting that these changes do not substantially alter the inherent chemical and electronic properties of polyaniline. Our results demonstrate that introducing different functional groups on a polymer backbone is an effective approach to obtain tailored conductive polymers with desirable properties while retaining their intrinsic properties, such as conductivity.MicroelectronicsElectrical Engineering, Mathematics and Computer Scienc

Panel of Ornament

From description by the V&A: This print comes from a set of six plates. A drawing for one of the other plates attributed to Perino del Vaga survives in the Uffizi. The two verses of Italian poetry make an explicit connection between the image and the excavation of underground rooms in Rome. Inscription at the bottom reads: Il poeta e'l pittor vanno di pare Et tira il lor adire tutto ad un segno Si come espresso in questo carte appare Fregiate d'opere et d'artificio degno Di questo Roma ci puo essempio dare Roma ricetto d'ogni chiaro ingegno Da le cui grotte ove mai non soggiorna Hor tanta luce a si bella arte torn

Thin Film Interface Fracture Properties at Scales Relevant to Microelectronics

Mechanical Maritime and Materials Engineerin