Materials Literature
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We use ab initio methods and neutron inelastic scattering (NIS) to study the structure, energetics, and dynamics of pure and Ti-doped sodium alanate (NaAlH_4), focusing on the possibility of substitutional Ti doping. The NIS spectrum is found to exhibit surprisingly strong and sharp two-phonon features. The calculatio…
A series of bifunctionalized mesoporous silica nanosphere-based (MSN) heterogeneous catalysts for the nitroaldol (Henry) reaction have been synthesized. A common 3-[2-(2-aminoethylamino)ethylamino]propyl (AEP) primary group and three different secondary groups, ureidopropyl (UDP), mercaptopropyl (MP), and allyl (AL) f…
The phase immiscibility and the excellent matching between Ag(001) and Fe(001) unit cells (mismatch 0.8 %) make Fe/Ag growth attractive in the field of low dimensionality magnetic systems. Intermixing could be drastically limited at deposition temperatures as low as 140-150 K. The film structural evolution induced by…
We report the first experiments on the high pressure phonon spectra of transition-metal nitrides HfN, ZrN, and NbN, obtained by Raman scattering measurements. Two pronounced bands, which are related to the acoustic part at low frequency around 200 cm$^{-1}$ and the optical part at high frequency around 550 cm$^{-1}$ o…
We present a lattice Boltzmann model to describe the spreading of droplets on topologically patterned substrates. We apply it to model superhydrophobic behaviour on surfaces covered by an array of micron-scale posts. We find that the patterning results in a substantial increase in contact angle, from $110^o$ to $156^o…
Cerium adatoms, deposited on a Ag(111) surface, are found by low-temperature scanning tunneling microscopy to self-assemble into large ordered hexagonal arrays covering macroscopically the entire surface. We show that the 32 A periodicity of the superlattice is caused by the interaction of surface-state electrons with…
We perform molecular dynamics simulations to study shape changes of carbon fullerenes and nanotubes with increasing temperature. At moderate temperatures, these systems gain structural and vibrational entropy by exploring the configurational space at little energy cost. We find that the soft phonon modes, which couple…
Dissipative particle dynamics (DPD) is a mesoscale modeling method for simulating equilibrium and dynamical properties of polymers in solution. The basic idea has been around for several decades in the form of bead-spring models. A few years ago, Groot and Warren established an important link between DPD and the Flory…
While biodegradable, biocompatible polyesters such as poly (lactic-co-glycolic acid) (PLGA) are popular materials for the manufacture of tissue engineering scaffolds, their surface properties are not particularly suitable for directed tissue growth. Although a number of approaches to chemically modify the PLGA surface…
We report the synthesis of new “branched” gold nanocrystals in high yield (over 90%) via a wet-chemical route. The branched nanocrystals exhibit a shape-dependent plasmon resonance that is red-shifted by 130−180 nm from the spherical particle wavelength. Discrete dipole approximation (DDA) calculations qualitatively r…
A highly regular mesh of hexagonal boron nitride with a 3-nanometer periodicity and a 2-nanometer hole size was formed by self-assembly on a Rh(111) single crystalline surface. Two layers of mesh cover the surface uniformly after high-temperature exposure of the clean rhodium surface to borazine (HBNH)3. The two layer…
The issue of dislocation formation in a strained epitaxial heterostructure was the focus of attention in the preceding chapter. Residual stress was assumed to originate from the combination of a mismatch in lattice parameters between the materials involved and the constraint of epitaxy. The discussion in Chapter 6 led…
Investigations have continued for economical utilization of lignocellulosic wastes, which represents one of the environmental problems facing the third world countries. The use of sugar-cane bagasse, rice straw, and waste paper as cellulose-containing waste stuff for obtaining soil conditioners is the basic aim of thi…
Incorporation of fillers in elastomers results in a profound effect on mechanical properties of the composites formed. Significant study has been carried out on this topic. Fillers are customarily classified into organic and inorganic. The latter class includes calcium carbonate, talc, barium sulphate, china clay (kao…
The existence of residual stress in films deposited on substrates and the effects of such stress on delamination and cracking were recognized as early as the nineteenth century. For example, an antimony film deposited on a substrate was found to be prone to cracking as a result of vibration or local application of hea…
Abstract Silver dendritic nanoparticles of uniform size and morphology have been prepared at room temperature using ascorbic acid as a reducing agent and sodium polyacrylate (PAA) as a protective agent in aqueous solution.
Abstract It was found that single-walled carbon nanotubes are stably dispersed into a low molecular-weight hydrogel (β-d-glucopyranoside–azonaphthol conjugate). From absorption and fluorescence spectral observations and microscopic images, it was shown that this gelator tends to orientate on the surface of SWNTs and s…
The size and molecular mass of water-soluble interpolyelectrolyte complex (PEC) formed between poly( l -glutamate) and poly(amido amine) dendrimer in aqueous solution were estimated as a function of the decreasing pH from the turbidities ( τ ) and their wavelength dependence, by comparison with numerical τ calculation…
The pore size distributions of bundled single-walled carbon nanotubes were investigated by N 2 adsorption and desorption. It was found that the pore sizes are in two main ranges: <5 nm and 10−100 nm. Furthermore, their heating in an inert gas, CO 2, or H 2 at 800 °C did not change the pore size distribution, even thou…
The ground-state geometries, electronic structures, and vibrational frequencies of alkali metal−B 5 - MB 5 (M = Li, Na, K, Rb, and Cs) and alkaline earth metal−B 5 - MB 5 + (M = Be, Mg, Ca, and Sr) clusters were investigated using ab initio self-consistent field and density functional theory (DFT) methods. Calculation…