Effect of sodium dodecylsulfate monomers and micelles on the stability of aqueous dispersions of titanium dioxide pigment nanoparticles against agglomeration and sedimentation.

Hypothesis: As more sodium dodecylsulfate (SDS) monomers adsorb at the water/titanium dioxide (TiO2) nanoparticles interface, the particles become more stable against agglomeration and sediment more slowly. SDS micelles are not expected to adsorb on the particles and affect the stability against agglomeration or sedimentation. Since micelles are smaller than the 300 nm TiO2 nanoparticles studied, they may introduce depletion forces which may affect the dispersion stability.

Benchmark Database for Ylidic Bond Dissociation Energies and Its Use for Assessments of Electronic Structure Methods.

We report a database of 18 ylidic bond dissociation energies obtained by using highly accurate quantum mechanical methods, and we use it to test approximate electronic structure methods. The new benchmark database is called YBDE18 and is used to test a large number of electronic structure methods, including eight wave function methods and 98 density functional exchange-correlation functionals. Among them, we include some very recent density functionals, including the SOGGA11 GGA functional, the SOGGA11-X hybrid GGA functional, the M11-L local meta-GGA functional, and the M11 range-separated hybrid meta-GGA functional.

Effect of Triton X-100 on the stability of aqueous dispersions of copper phthalocyanine pigment nanoparticles.

The effect of Triton X-100 on the colloidal dispersion stability of CuPc-U (unsulfonated and hydrophobic) and CuPc-S (surface sulfonated and hydrophilic) particles in aqueous solutions (water and NaNO(3)) was investigated at 25 °C. Its adsorption density was determined from surfactant concentrations analyzed by an HPLC method with a UV detector. The experimental dispersion stability ratios of the particles were determined from dynamic light scattering (DLS) data, with the Rayleigh-Debye-Gans (RDG) light scattering theory.

Computation of Nonretarded London Dispersion Coefficients and Hamaker Constants of Copper Phthalocyanine.

A time-dependent density functional theory (TDDFT) scheme has been validated for predictions of the dispersion coefficients of five molecules (H2O, NH3, CO2, C6H6, and pentane) and for predictions of the static dipole polarizabilities of three organometallic compounds (TiCl4, OsO4, and Ge(CH3)4). The convergence of grid spacing has been examined, and two types of pseudopotentials and 13 density functionals have been tested. The nonretarded Hamaker constants A11 are calculated by employing a semiempirical parameter a along with the standard Hamaker constant equation.

Colloidal dispersion stability of CuPc aqueous dispersions and comparisons to predictions of the DLVO theory for spheres and parallel face-to-face cubes.

The dispersion stability and the zeta potentials of nonspherical crystalline (beta-form) copper phthalocyanine (CuPc) particles of hydrodynamic diameter d(h) approximately = 90 nm were investigated at 25 degrees C in water and in aqueous solutions of NaNO(3). The electrolyte concentrations c ranged from 1 to 500 mM and the particle concentrations ranged from 50 to 10,000 ppm (0.005 to 1 wt %).

Benchmark Data for Noncovalent Interactions in HCOOH···Benzene Complexes and Their Use for Validation of Density Functionals.

We present benchmark energetic data for the HCOOH···benzene complexes. The benchmark data were determined by a composite approach based on CCSD(T) calculations. Final binding energies (kcal/mol) are in the range of 1.

Carbon nanotubes and nanowires for biological sensing.

This chapter reviews the recent development in biological sensing using nanotechnologies based on carbon nanotubes and various nanowires. These 1D materials have shown unique properties that are efficient in interacting with biomolecules of similar dimensions, i.e.

Ultrasensitive label-free DNA analysis using an electronic chip based on carbon nanotube nanoelectrode arrays.

We report the detection of DNA PCR amplicons using an ultrasensitive label-free electronic technique based on multiwalled carbon nanotube (MWNT) nanoelectrode arrays embedded in an SiO(2) matrix. Specific PCR amplicons are reliably detected using electrochemical (EC) methods through allele-specific oligonucleotide hybridization. The inherent guanine bases in the DNA amplicon target of [Formula: see text] bases serve as signal moieties with the aid of Ru(bpy)(3)(2+) mediators, providing an amplified anodic current associated with the oxidation of guanine groups at the nanoelectrode surface.

A high-performance glucose biosensor based on monomolecular layer of glucose oxidase covalently immobilised on indium-tin oxide surface.

In this paper, a mediatorless amperometric glucose biosensor based on direct covalent immobilisation of monomolecular layer of glucose oxidase (GOx) on a semiconducting indium-tin oxide (ITO) is demonstrated. The abundance of surface hydroxyl functional group of ITO allows it to be used as a suitable platform for direct covalent immobilisation of the enzyme for sensor architecture. The anodic current corresponding to electrochemical oxidation of the enzymatic product, hydrogen peroxide, at a sputtered Pt electrode at 0.