Multilayers formed by the sodium salt of poly(4-styrene sulfonate), PSS, and poly(diallyldimethylammonium) chloride, PDADMAC, have been built electrostatic self-assembly from polyelectrolyte aqueous solutions different ionic strengths. The growth multilayers has followed using dissipative quartz crystal microbalance ellipsometry. Neutron reflectometry XPS data indicate that PSS PDADMAC layers interpenetrate leading to an almost homogeneous polymer film. results show on increasing [NaCl]...

The structure and the interaction potential of monolayers charged polystyrene microparticles at fluid interfaces have been studied by optical microscopy. Microparticles different sizes over a broad range surface particle densities. structural characterization is based on analysis images obtained digital From experimental images, radial distribution functions, hexagonal bond order correlation temporal orientational functions calculated for monolayer states both air/water oil/water interfaces....

Abstract The hydrogen bonds involving sulfur in the furfuryl mercaptan monohydrate are compared with interactions originating from hydroxyl group alcohol. dimers water were created a supersonic jet expansion and characterized using microwave spectroscopy supporting molecular orbital calculations. In alcohol–water, single isomer is observed, which molecule forms an insertion complex two simultaneous to alcohol (O−H⋅⋅⋅O w ) ring oxygen (O −H⋅⋅⋅O r ). When replaced by thiol mercaptan–water,...

This work presents a simply methodology for coating small unilamellar liposomes bearing different degrees of positive charge with polyelectrolyte multilayers using the sequential Layer-by-Layer (LbL) deposition method. The were made mixtures DOPC (1,2-dioleyl-sn-glycero-3-phosphocoline) and DODAB (dimethyl dioctadecyl ammonium bromide), coated by alternated layers sodium salt poly(4-styrenesulfonate), PSS, poly(allylamine), PAH, as polyanion polycations, respectively. results shows that zeta...

π-Stacking is a common descriptor for face-to-face attractive forces between aromatic hydrocarbons. However, the physical origin of this interaction remains debatable. Here we examined π-stacking in model homodimer formed by two thiol-substituted naphthalene rings. Two isomers 2-naphthalenethiol dimer were discovered using rotational spectroscopy, sharing parallel-displaced crossed orientation and absence thiol–thiol hydrogen bonds. One presents C2 symmetry, structurally analogous to global...

The monohydrates of thenyl alcohol and mercaptan have been probed in a supersonic jet expansion using chirped-pulse Fabry-Perot Fourier-transform microwave spectroscopy. rotational spectra revealed single isomer for each the dimers. hydrate is stabilized by an O-HOw hydrogen bond between water, with water acting as proton acceptor additionally engaging Ow-Hπ interaction ring. Conversely, behaves donor hydrate, linking to thiol group though Ow-HS secondary interactions In both dimers retains...

In order to simulate the diffusion kinetics during thermal treatments in SiGe heterostructures, a physically-based atomistic model including chemical and strain effects has been developed implemented into nonlattice kinetic monte carlo (KMC) framework. This is based on description of transport capacities native point defects (interstitials vacancies) with different charge states alloys whole composition range. Lattice atom diffusivities have formulated terms defect transport, taking account...

The homodimers of transiently chiral molecules offer physical insight into the process molecular recognition, preference for homo or heterochiral aggregation and nature non-covalent interactions stabilizing adducts. We report observation benzyl mercaptan dimer in isolation conditions a supersonic jet expansion, using broadband (chirped-pulse) microwave spectroscopy. A single homochiral isomer was observed dimer, stabilized by cooperative sequence S-H···S S-H···π hydrogen bonds. structural...

A comprehensive atomistic model for arsenic in silicon which includes charge effects and is consistent with first-principles calculations arsenic-vacancy cluster energies has been developed. Emphasis put reproducing the electrical deactivation annealed profiles preamorphized silicon. The simulations performed an kinetic Monte Carlo simulator suggest a predominant role of mobile interstitial experiments provide good understanding behavior during annealing.

An accurate physically based Fermi-level modeling approach, amenable to be implemented in an atomistic process simulator, is reported. The kinetic Monte Carlo method used for point and extended defects, conjunction with a quasiatomistic, continuum approach treatment carrier densities. model implements charge reactions electric bias according the local Fermi level, pairing break-up between particles, clustering-related dopant deactivation, Fermi-level-dependent solubility. We derive...

In a recent article (ACS Catal. 2018, 8, 11119–11133), comprehensive catalytic mechanism is proposed to explain the effects of residual water on reactivity and regioselectivity tris(pentafluorophenyl)borane catalyst in ring-opening reaction 1,2-epoxyoctane by 2-propanol. Using it as representative example common trend followed also other groups, we show that heavily under-constrained (loose) kinetic modeling approach employed can lead several pitfalls propose an alternative, more stringent...

Ion implantation induced damage accumulation is crucial to the simulation of silicon processing. We present a physically based model, implemented in nonlattice atomistic kinetic Monte Carlo simulator, that can simulate diverse range interesting experimental observations. The model able reproduce ion-mass dependent amorphous-crystalline transition temperature ions from C Xe, amorphous layer thickness for amorphizing implants, superlinear increase with dose, and two-layered distribution...

An atomistic Monte Carlo code to simulate the deposition and annealing of three-dimensional polycrystalline thin films is presented. Atoms impinge on substrate with selected angular distributions, grains are nucleated different crystalline orientations, defined by tilt rotation angles. Grain boundaries appear naturally when islands coalesce, can migrate during both simulations. In this work we present simulations aluminum films. We examine influence temperature, rate, adhesion morphology The...

We introduce a model for damage accumulation up to amorphization, based on the ion-implant structures commonly known as amorphous pockets. The is able reproduce silicon amorphous-crystalline transition temperature C, Si, and Ge ion implants. Its use an analysis tool reveals unexpected bimodal distribution of defect population around characteristic size, which larger heavier ions. split in both size composition, with small, pure interstitial vacancy clusters below pockets balanced mixture...

A novel DFT-based Reaction Kinetics (DFT-RK) simulation approach, employed in combination with real-time data from reaction monitoring instrumentation (like UV-vis, FTIR, Raman, and 2D NMR benchtop spectrometers), is shown to provide a detailed methodology for the analysis design of complex synthetic chemistry schemes. As an example, it applied opening epoxides by titanocene THF, catalytic system abundant experimental available. Through DFT-RK IR data, we have developed comprehensive...

Phase transitions in two-dimensional (2D) systems are of considerable fundamental and practical importance. However, the kinetics these processes difficult to predict understand, even simple for which equilibrium states properly described, owing difficulty studying crystallites with single-particle resolution free defects. Here we introduce an alternative method sublimation 2D colloidal by a sudden induction repulsive forces between particles. The kinetics, studied real space microscopy...

We present a rotational-computational investigation of the aromatic mercaptan 2-phenylethanethiol, addressing its potential energy surface, conformational equilibrium, internal dynamics and intramolecular interactions. The experiment used broadband chirped-pulse Fourier transform microwave spectroscopy in supersonic jet expansion, recording rotational spectrum 2-8 GHz frequency region. Two different conformers were detected spectrum. most intense transitions correspond to skew...

We have studied the dispersion of capillary waves on surface aqueous solutions cationic surfactant dodecylammonium chloride (DAC) by using quasi-elastic light scattering (SQELS) combined with equilibrium tension measurements. To test role electrostatics dynamical behavior adsorbed monolayer at air/solution interface, experiments in absence and presence an inert electrolyte (KCl) been performed. The results analyzed terms Frumkin−Davies equation state. For salt-free system, Lucassen−van den...

Particle tracking has been shown to be a powerful technique for measuring bulk and interfacial rheology of fluids.The Brownian motion microparticles trapped at interfaces is very sensitive the viscosity subphase, contact angle particles.The Stokes-Einstein relation fulfilled if friction factor properly taken into account.The diffusion coefficient latex spread on surfactant monolayers allows one calculate shear monolayer using Danov's theory.Good agreement was found with previous results...

The internal organization of polyelectrolyte layers deposited on colloidal templates plays a very important role for the potential applications these systems as capsules drug delivery purposes. mutual arrangement oppositely charged upon their deposition positively liposomes has been studied by combining up three different scattering techniques and Electronic Spin Resonance, which provided information about inter-layer interactions effect final structure capsules. sequential polyelectrolytes...