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A microfluidic approach is described for generating capsules of biopolymer hydrogels at room temperature and with good control of particle size distribution and internal structure. The time of gelation and/or the concentration of the cross-linking agent in the continuous phase are controlled in order to achieve control over the internal structure of biomicrogels from capsules to gradient microgels to microgels with a uniform structure.

A method to measure charge within a molecular circuit that shows negative differential resistance by conducting probe atomic force microscopy is presented. It is observed that the voltage region over which conduction was enhanced correlated strongly with the region over which the scanning probe tip experienced capacitive attraction to the surface.

A study was conducted to report the coupling of vibrational excitations to photo induced electron transfer in a mixed-valence transition metal complex [(CN)(sub 5)OsCNRu(NH(sub 3))(sub 5)](super -). The studies observed excitations in the non-totally symmetric vibrational mode accompanying the reverse electron transfer process in both formamide (FA) and deuterium oxide (D(sub 2)O) solutions.

A semi classical theory of vibrational energy relaxation (VER) was studied which was extended to the case of molecular liquids and was used for calculating the VER rate constant in neat liquid oxygen at 77 K. The studies stated that VER in liquid oxygen was dominated by a purely quantum mechanical term which vanishes at the classical limit.

The first application of semiclassical methodology to the calculation of vibrational energy relaxation (VER) rate constants in condensed phase systems is presented. The studies stated that VER of high-frequency molecular vibrations was dominated by a purely quantum-mechanical term which vanishes in the classical limit.

The studies stated the dynamics of photochemical reactions exhibiting chemically which induced electron spin polarization (CIDEP) were modeled by kinetic equations that included all relevant parameters, including reaction of excited precursor as both a singlet and a triplet and spin exchange during radical encounters.

Quasielastic helium atom scattering (QHAS) techniques are used to study the diffusion and lateral vibrations of a low coverage Theta(sub Na)=0.043 of sodium atoms on a Pt(111) surface. On account of the competition between on-top and hollow site adsorption on the hexagonal Pt(111) surface, this system provides a comparison with the diffusion of Na/Cu(001).

The barrier to internal rotation of a methyl group attached to an unsaturated linkage in an organic molecule is changed by complex formation with a weakly bound argon atom. This is a result of a dispersion interaction between the argon and pie-electrons of the molecule in the vicinity of the methyl group.

A variable temperature scanning tunneling microscope was used to characterize interactions between diffusing hydrogen sulfide and water molecules and various coadsorbates on Cu(001). A single hydrogen atom abstraction in simple bimolecular reactions was induced and observed with atomic resolution.

The electronic excited-state at the air/water solvation dynamics of coumarin 314 adsorbed at the air/water interface was investigated Using femtosecond time-resolved second-harmonic generation (TRSHG). With the aid of a tunable optical parametric generator giving a spectral peak at 419+/- 3nm, the second-harmonic spectra of C314 was determined at air/water interface.

Potential pulse perturbation time-resolved scanning tunneling microscopy is used to investigate the growth and dissolution dynamics of nanoscale islands. It is concluded that the properties of the islands can be controlled by tailoring the potential pulse perturbation.

Gold and silicon nanostructures are produced by condensing vacuum-evaporated materials onto nanometer-sized etch-pit templates performed on the surface of highly oriented pyrolytic graphite. Scanning tunneling spectroscopy is used to further investigate the electronic properties of multilayered silicon nanostructures.

Atomic Force Microscopy has great scope to analyze contour lengths of polymers/macromolecules at surfaces. The values of persistence, lengths and other parameters obtained from filling the force-distance profiles indicate that the measurements typically involved stretching single PDMS molecules grafted to the underlying surfaces.

Vibrational excitations after reverse electron transfer in a CN-bridged mixed valance complex are reported. The relationship between the observed spectral dynamics and the reverse electron transfer process are discussed.

The impact of the polymer-solvent interfacial free energy on the collapse of the polystyrene chain in water, as well as the aqueous solutions is determined. The change in the free energy is shown to be directly related to the force of the collapsed polymer in a bad solvent.

An evaluation of absolute rate models for electron transfer was undertaken, but the comparison is only limited to water since it is the only solvent for which the necessary parameters are available. The experimental absolute rates were obtained from ultrafast pump-probe measurements on the metal-metal charge-transfer (MMCT) band of electron transfer reactions. On the other hand, the theoretical calculations were obtained by combining MMCT resonance Raman data with an MMCT band shape analysis.

The article describes the force-induced mechanics of individual polystyrene (PS130000) in strongly poor, moderately poor, and good solvent conditions.

Single-molecule electrical conduction studies are used to evaluate the way molecular linking unit influences the tunneling efficiency in metal-molecule-metal junctions. The results demonstrate that the molecule with conjugated double thiol linkers displays higher conduction in gold-molecule-gold junctions than non-conjugated single thiol-gold contacts.

An experimental data to characterize the diblock copolymer interactions with a silicon nitride AFM tip is described. The surface unbinding of individual polymer blocks under conditions where a specific solvent-polymer-surface structure is expected, is also described.

Noncovalent functionalization of carbon nanotubes enables on e to tailor their properties while still preserving nearly all of the nanotube's intrinsic properties. The report describes a new nonwrapping approach to noncovalent engineering of carbon nanotube surfaces that leads to a more than 20 -fold enhancement of solubility of small SWNTs and enables superior control of the relative placement of functionalities on the nanotube surface.

Researchers collected and studied the resonance Raman spectra of (CN)5FeCNRu(NH3)5 in three solvents including water, formamide and N-methylformamide as well as the excitation profile of this compound in D2O. Findings showed that solvent dependence of the resonance Raman and infrared spectra may reflect solvent electrostatic effects on the ground electronic state wave function of the solute which is localized in the iron center. Strong solute-solvent interactions may result in solvent-induced alterations in solute electronic and nuclear structure.

Nitric oxide (NO) is important in bioregulation, and RS-NOs have an important role in regulating NO reactivity and toxicity. RS-NO was characterized using circular dichroism (CD), and NO, bound to the cystein (Cys) thiol, glutathione (GSB) or bovine serum albumin (BSA), is located with respect to the asymmetric centre of the amino acid.

Hydrophobic interactions guide protein folding, multidomain protein assembly, receptor–ligand binding, membrane formation, and cellular transportation. On the macroscale, hydrophobic interactions consist of the aggregation of “oil-like” objects in water by minimizing the interfacial energy. However, studies of the hydration behavior of small hydrophobic molecules have shown that the microscopic (∼1 nm) hydration mechanism differs fundamentally from its macroscopic counterpart. Theoretical studies over the last two decades have pointed to an intricate dependence of molecular hydration mechanisms on the length scale. The microscopic-to-macroscopic crossover length scale is critically important to hydrophobic interactions in polymers, proteins, and other macromolecules. Accurate experimental determination of hydration mechanisms and interaction strengths directly influence our understanding of protein folding. [ABSTRACT FROM AUTHOR]