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Zeta Potential Titration
Zeta potential titration is a titration of heterogeneous systems, for example colloids and emulsions. Solids in such systems have very high surface area. This type of titration is used to study the zeta potential of these surfaces under different conditions. Details of zeta potential definition and measuring techniques can be found in the International Standard.International Standard ISO 13099-1, 2012, "Colloidal systems – Methods for Zeta potential determination- Part 1: Electroacoustic and Electrokinetic phenomena" Iso-electric Point The iso-electric point is one such property. The iso-electric point is the pH value at which the zeta potential is approximately zero. At a pH near the iso-electric point (± 2 pH units), colloids are usually unstable; the particles tend to coagulate or flocculate. Such titrations use acids or bases as titration reagents. Tables of iso-electric points for different materials are available. The attached figure illustrates results of such titra ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Titration
Titration (also known as titrimetry and volumetric analysis) is a common laboratory method of quantitative chemical analysis to determine the concentration of an identified analyte (a substance to be analyzed). A reagent, termed the ''titrant'' or ''titrator'', is prepared as a standard solution of known concentration and volume. The titrant reacts with a solution of ''analyte'' (which may also be termed the ''titrand'') to determine the analyte's concentration. The volume of titrant that reacted with the analyte is termed the ''titration volume''. History and etymology The word "titration" descends from the French word ''titrer'' (1543), meaning the proportion of gold or silver in coins or in works of gold or silver; i.e., a measure of fineness or purity. ''Tiltre'' became ''titre'', which thus came to mean the "fineness of alloyed gold", and then the "concentration of a substance in a given sample". In 1828, the French chemist Joseph Louis Gay-Lussac first used ''titre'' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rutile
Rutile is an oxide mineral composed of titanium dioxide (TiO2), the most common natural form of TiO2. Rarer polymorphs of TiO2 are known, including anatase, akaogiite, and brookite. Rutile has one of the highest refractive indices at visible wavelengths of any known crystal and also exhibits a particularly large birefringence and high dispersion. Owing to these properties, it is useful for the manufacture of certain optical elements, especially polarization optics, for longer visible and infrared wavelengths up to about 4.5 micrometres. Natural rutile may contain up to 10% iron and significant amounts of niobium and tantalum. Rutile derives its name from the Latin ('red'), in reference to the deep red color observed in some specimens when viewed by transmitted light. Rutile was first described in 1803 by Abraham Gottlob Werner. Occurrence Rutile is a common accessory mineral in high-temperature and high-pressure metamorphic rocks and in igneous rocks. Thermodynamically, ru ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Condensed Matter Physics
Condensed matter physics is the field of physics that deals with the macroscopic and microscopic physical properties of matter, especially the solid and liquid phases which arise from electromagnetic forces between atoms. More generally, the subject deals with "condensed" phases of matter: systems of many constituents with strong interactions between them. More exotic condensed phases include the superconducting phase exhibited by certain materials at low temperature, the ferromagnetic and antiferromagnetic phases of spins on crystal lattices of atoms, and the Bose–Einstein condensate found in ultracold atomic systems. Condensed matter physicists seek to understand the behavior of these phases by experiments to measure various material properties, and by applying the physical laws of quantum mechanics, electromagnetism, statistical mechanics, and other theories to develop mathematical models. The diversity of systems and phenomena available for study makes condensed ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Colloidal Chemistry
Interface and colloid science is an interdisciplinary intersection of branches of chemistry, physics, nanoscience and other fields dealing with colloids, heterogeneous systems consisting of a mechanical mixture of particles between 1 nm and 1000 nm dispersed in a continuous medium. A colloidal solution is a heterogeneous mixture in which the particle size of the substance is intermediate between a true solution and a suspension, i.e. between 1–1000 nm. Smoke from a fire is an example of a colloidal system in which tiny particles of solid float in air. Just like true solutions, colloidal particles are small and cannot be seen by the naked eye. They easily pass through filter paper. But colloidal particles are big enough to be blocked by parchment paper or animal membrane. Interface and colloid science has applications and ramifications in the chemical industry, pharmaceuticals, biotechnology, ceramics, minerals, nanotechnology, and microfluidics, among others. Ther ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chemical Mixtures
A chemical substance is a form of matter having constant chemical composition and characteristic properties. Some references add that chemical substance cannot be separated into its constituent elements by physical separation methods, i.e., without breaking chemical bonds. Chemical substances can be simple substances (substances consisting of a single chemical element), chemical compounds, or alloys. Chemical substances are often called 'pure' to set them apart from mixtures. A common example of a chemical substance is pure water; it has the same properties and the same ratio of hydrogen to oxygen whether it is isolated from a river or made in a laboratory. Other chemical substances commonly encountered in pure form are diamond (carbon), gold, table salt (sodium chloride) and refined sugar (sucrose). However, in practice, no substance is entirely pure, and chemical purity is specified according to the intended use of the chemical. Chemical substances exist as solid ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electroacoustic Phenomena
Electroacoustic phenomena arise when ultrasound propagates through a fluid containing ions. The associated particle motion generates electric signals because ions have electric charge. This coupling between ultrasound and electric field is called electroacoustic phenomena. The fluid might be a simple Newtonian liquid, or complex heterogeneous dispersion, emulsion or even a porous body. There are several different electroacoustic effects depending on the nature of the fluid.Dukhin, A.S. and Goetz, P.J. ''Characterization of liquids, nano- and micro- particulates and porous bodies using Ultrasound'', Elsevier, 2017 * Ion vibration current (IVI) and potential, an electric signal that arises when an acoustic wave propagates through a homogeneous fluid. *Streaming vibration current (SVI) and potential, an electric signal that arises when an acoustic wave propagates through a porous body in which the pores are filled with fluid. * Colloid vibration current (CVI) and potential, an elect ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electrophoretic Light Scattering
Electrophoretic light scattering (also known as laser Doppler electrophoresis and phase analysis light scattering ) is based on dynamic light scattering. The frequency shift or phase shift of an incident laser beam depends on the dispersed particles mobility. With ''dynamic light scattering'', Brownian motion causes particle motion. With ''electrophoretic'' light scattering, oscillating electric field performs this function. The method is used for measuring electrophoretic mobility, from which zeta potential can then be calculated. Instruments for applying the method are commercially available from several manufacturers. The last set of calculations requires information on viscosity and dielectric permittivity of the dispersion medium; appropriate electrophoresis theory is also required. Sample dilution is often necessary to eliminate multiple scattering of the incident laser beam and/or particle interactions. Instrumentation A laser beam passes through the electrophoresis cel ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Microelectrophoresis
Microelectrophoresis is a method of studying electrophoresis of various dispersed particles using optical microscopy. This method provides image of moving particles, which is its unique advantage. e.g. observation of RBCs, neutrophiles and bacteria. This type of electrophoresis is carried out in a closed medium with critical observations by focusing and adjusting the lens of microscope. :Complexity of this method is associated with electro-osmosis generated by electric field influence on the double layers of the sample cell walls. In the usually used closed cells this creates Poiseuille type back flow, leading to parabolic velocity profile. There are two stationary layers, where fluid does not move. Position of these stationary layer regarding cell walls depends on the cell geometry. It is possible to focus microscope on this stationary layers and observe particles motion not affected with electro-osmosis. The second complexity comes from necessity of diluting sample, if it was ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Indicator
Indicator may refer to: Biology * Environmental indicator of environmental health (pressures, conditions and responses) * Ecological indicator of ecosystem health (ecological processes) * Health indicator, which is used to describe the health of a population * Honeyguides, also known as "indicator birds", a family of Old World tropical birds ** ''Indicator'' (genus), a genus of birds in the honeyguide family * Indicator species, a species that defines a characteristic of an environment * Indicator bacteria, bacteria used to detect and estimate the level of fecal contamination of water * Indicator organism, organisms used to measure such things as potential fecal contamination of environmental samples * Indicator plant, a plant that acts as a measure of environmental conditions * Indicator value, one of two terms in ecology referring to the classification of organisms * Iodine–starch test, a method to test for the presence of starch or iodine. Chemistry * Complexometric i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Zeta Potential
Zeta potential is the electrical potential at the slipping plane. This plane is the interface which separates mobile fluid from fluid that remains attached to the surface. Zeta potential is a scientific term for electrokinetic potential in colloidal dispersions. In the colloidal chemistry literature, it is usually denoted using the Greek letter zeta (ζ), hence ''ζ-potential''. The usual units are volts (V) or, more commonly, millivolts (mV). From a theoretical viewpoint, the zeta potential is the electric potential in the interfacial double layer (DL) at the location of the slipping plane relative to a point in the bulk fluid away from the interface. In other words, zeta potential is the potential difference between the dispersion medium and the stationary layer of fluid attached to the dispersed particle. The zeta potential is caused by the net electrical charge contained within the region bounded by the slipping plane, and also depends on the location of that plane. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chemical Stability
In chemistry, chemical stability is the thermodynamic stability of a chemical system. Thermodynamic stability occurs when a system is in its lowest energy state A quantum mechanical system or particle that is bound—that is, confined spatially—can only take on certain discrete values of energy, called energy levels. This contrasts with classical particles, which can have any amount of energy. The te ..., or in chemical equilibrium with its environment. This may be a dynamic equilibrium in which individual atoms or molecules change form, but their overall number in a particular form is conserved. This type of chemical thermodynamic equilibrium will persist indefinitely unless the system is changed. Chemical systems might undergo changes in the phase of matter or a set of chemical reactions. State A is said to be more thermodynamically stable than state B if the Gibbs free energy of the change from A to B is positive. Versus reactivity Thermodynamic stability appl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Surfactant
Surfactants are chemical compounds that decrease the surface tension between two liquids, between a gas and a liquid, or interfacial tension between a liquid and a solid. Surfactants may act as detergents, wetting agents, emulsifiers, foaming agents, or dispersants. The word "surfactant" is a blend of ''surface-active agent'', coined . Agents that increase surface tension are "surface active" in the literal sense but are not called surfactants as their effect is opposite to the common meaning. A common example of surface tension increase is salting out: by adding an inorganic salt to an aqueous solution of a weakly polar substance, the substance will precipitate. The substance may itself be a surfactant – this is one of the reasons why many surfactants are ineffective in sea water. Composition and structure Surfactants are usually organic compounds that are amphiphilic, meaning each molecule contains both a hydrophilic "water-seeking" group (the ''head''), a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
