John Francis Miller

Enlighten Scientific LLC

An apparatus is described that can determine electrophoretic mobilities of polar and nonpolar colloidal dispersions down to 1 × 10−12 m2 s−1 V−1, with typical resolutions of 0.5 to 5%, depending on the nature of the dispersion being studied. The diffusion coefficient and velocity of the sample may be determined simultaneously with the electrophoret...

How To Measure Zeta Potential More Confidently * Maximize the confidence in your measurements * Learn the importance of knowing the science, instrument - and business organization * I explain the origin of zeta potential, how to measure it and the common mistakes people make * I don't go into unnecessary detail - only the basics you need * This is...

An apparatus and method to obtain electrophoretic mobility information from a dilute colloidal dispersion using electrophoretic light scattering (ELS) is disclosed. Both laser Doppler electrophoresis and phase analysis light scattering data analysis methods may be applied to a scattered light signal simultaneously. Unlike previous ELS apparatuses a...

Studies are reported of the measurement of electrophoretic mobilities of bovine serum albumin (BSA) in aqueous potassium chloride solutions as a function of ionic strength and pH using next generation electrophoretic light scattering (NG-ELS). It is demonstrated that the use of palladium or platinum electrodes should be avoided and that platinized...

We report the synthesis of sterically-stabilized diblock copolymer particles at 20% w/w solids via reversible addition-fragmentation chain transfer (RAFT) aqueous dispersion polymerization of N,N'-dimethylacrylamide (DMAC) in highly salty media (2.0 M (NH4)2SO4). This is achieved by selecting a well-known zwitterionic water-soluble polymer, poly(2-...

Introduction More than fifty years after the commercialization of the Ventolin metered-dose inhaler (MDI), its constituent active ingredient, salbutamol sulfate (SS) remains the most prescribed short-acting beta agonist for the first-line treatment of acute asthma attacks and the metered-dose inhaler remains its primary dosage form. The first gener...

A method for measuring electrophoretic mobility of particles dispersed in a liquid medium which implements electrophoretic light scattering (ELS) via directing light from a laser source through a sample of a dilute dispersion of particles in a liquid, said method comprising calculating a Doppler shift frequency distribution of the scattered light u...

For certain commercial applications such as enhanced oil recovery, sterically stabilized colloidal dispersions that exhibit high tolerance toward added salt are desirable. Herein, we report a series of new cationic diblock copolymer nanoparticles that display excellent colloidal stability in concentrated aqueous salt solutions. More specifically, p...

Measurement of zeta potential is common throughout many industries including pharmaceuticals, foodstuffs, consumer health products, and cosmetics. It has become an essential tool available to product development scientists and manufacturing quality control departments to assess the physical stability of colloidal products against unwanted phenomena...

https://www.aiche.org/conferences/aiche-annual-meeting/2012/proceeding/paper/645a-quantitative-characterization-powder-flow-under-dynamic-conditions-rotating-drum Control of the flow properties of powders during one or more unit operations of a manufacturing process is an essential part of ensuring the process is well-controlled. Many assays exist...

A new instrument based on the principles of phase analysis light scattering (PALS) applied to the measurement of electrophoretic mobilities has been produced. Such measurements are particularly useful in the study of dispersions in non-polar media since for a given zeta potential, the mobility is proportional to the dielectric constant. It is also...

We have developed a new instrument that combines phase analysis light scattering (PALS) with dielectric spectroscopy (DS) for characterizing the electrokinetic and dielectric properties of dilute colloidal suspensions. PALS measures the electrophoretic mobilities of colloidal particles, and DS provides frequency spectra of dielectric permittivity a...

The electrophoretic mobilities for an overbased calcium additive dispersed in a variety of non-polar hydrocarbon media have been determined using phase-analysis light scattering. It is evident that a significant charge exists at the particle/ liquid interface, probably as a result of the alkyl benzene sulphonate surfactant being incorporated into t...

The theory of three types of dynamic light-scattering experiments applied to colloidal dispersions subjected to an external sinusoidal field is presented. The first-order and second-order heterodyne autocorrelation functions for the scattered light are calculated. The classical correlation experiments are compared with the more recent technique of...

An apparatus is described that can determine electrophoretic mobilities of polar and nonpolar colloidal dispersions down to 1 X 10 -12 m2s-1V-1 with typical resolutions of 0.5 to 5%, depending on the nature of the dispersion being studied. The diffusion coefficient and settling/convection velocity of the sample may be determined simultaneously with...

The polymerization of aniline by persulphate anion in aqueous solution was studied as a function of oxidant/monomer initial mole ratio (r). For values of r less than ∼ 1.15, the conductivity, yield, elemental composition and degree of oxidation of the resulting polyaniline product are essentially independent of r. However, higher oxidant/monomer in...

Stable, aqueous dispersions of polypyrrole latex particles were prepared by a dispersion polymerization technique using ferric chloride as the initiator and partially hydrolyzed poly(vinyl acetate) as the stabilizer. Monodisperse particles in the approximate size range from 100 to 150 nm diameter were obtained. At the optimum PVA:pyrrole mass ratio...