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Gold Number
The gold number is the minimum weight (in milligrams) of a protective colloid/lyophilic colloid required to prevent the coagulation of 10 ml of a standard hydro gold sol when 1 ml of a 10% sodium chloride solution is added to it. It was first used by Richard Adolf Zsigmondy in 1901. An electrical double layer is normally present on the gold sol particles, resulting in electrostatic repulsion between the particles. The sodium chloride ions disrupt this electrical double layer, causing coagulation to occur. The coagulation of gold sol results in an increase in particle size, indicated by a colour change from red to blue or purple. The higher the gold number, the lower the protective power of the colloid, because a greater amount of colloid is required to prevent coagulation. The gold number of some colloid A colloid is a mixture in which one substance consisting of microscopically dispersed insoluble particles is suspended throughout another substance. Some definitions sp ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Protective Colloid/lyophilic Colloid
Protection is any measure taken to guard something against damage caused by outside forces. Protection can be provided to physical objects, including organisms, to systems, and to intangible things like civil and political rights. Although the mechanisms for providing protection vary widely, the basic meaning of the term remains the same. This is illustrated by an explanation found in a manual on electrical wiring: Some kind of protection is a characteristic of all life, as living things have evolved at least some protective mechanisms to counter damaging environmental phenomena, such as ultraviolet light. Biological membranes such as bark on trees and skin on animals offer protection from various threats, with skin playing a key role in protecting organisms against pathogens and excessive water loss. Additional structures like scales and hair offer further protection from the elements and from predators, with some animals having features such as spines or camouflage servi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gold
Gold is a chemical element; it has chemical symbol Au (from Latin ) and atomic number 79. In its pure form, it is a brightness, bright, slightly orange-yellow, dense, soft, malleable, and ductile metal. Chemically, gold is a transition metal, a group 11 element, and one of the noble metals. It is one of the least reactivity (chemistry), reactive chemical elements, being the second-lowest in the reactivity series. It is solid under standard temperature and pressure, standard conditions. Gold often occurs in free elemental (native state (metallurgy), native state), as gold nugget, nuggets or grains, in rock (geology), rocks, vein (geology), veins, and alluvial deposits. It occurs in a solid solution series with the native element silver (as in electrum), naturally alloyed with other metals like copper and palladium, and mineral inclusions such as within pyrite. Less commonly, it occurs in minerals as gold compounds, often with tellurium (gold tellurides). Gold is resistant to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sol (colloid)
A sol is a colloidal solution made out of tiny solid particles in a continuous liquid medium. Sols are stable, so that they do not settle down when left undisturbed, and exhibit the Tyndall effect, which is the scattering of light by the particles in the colloid. The size of the particles can vary from 1 nm - 100 nm. Examples include amongst others blood, pigmented ink, cell fluids, paint, antacids and mud. Artificial sols can be prepared by two main methods: dispersion and condensation. In the dispersion method, solid particles are reduced to colloidal dimensions through techniques such as ball milling and Bredig's arc method. In the condensation method, small particles are formed from larger molecules through a chemical reaction. The stability of sols can be maintained through the use of dispersing agents, which prevent the particles from clumping together or settling out of the suspension. Sols are often used in the sol-gel process, in which a sol is converted into a gel ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sodium Chloride
Sodium chloride , commonly known as Salt#Edible salt, edible salt, is an ionic compound with the chemical formula NaCl, representing a 1:1 ratio of sodium and chloride ions. It is transparent or translucent, brittle, hygroscopic, and occurs as the mineral halite. In its edible form, it is commonly used as a condiment and curing (food preservation), food preservative. Large quantities of sodium chloride are used in many industrial processes, and it is a major source of sodium and chlorine compounds used as feedstocks for further Chemical synthesis, chemical syntheses. Another major application of sodium chloride is deicing of roadways in sub-freezing weather. Uses In addition to the many familiar domestic uses of salt, more dominant applications of the approximately 250 million tonnes per year production (2008 data) include chemicals and de-icing.Westphal, Gisbert ''et al.'' (2002) "Sodium Chloride" in Ullmann's Encyclopedia of Industrial Chemistry, Wiley-VCH, Weinheim . Chem ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Richard Adolf Zsigmondy
Richard Adolf Zsigmondy (; 1 April 1865 – 23 September 1929) was an Austrian-born chemist. He was known for his research in colloids, for which he was awarded the Nobel Prize in Chemistry in 1925, as well as for co-inventing the slit- ultramicroscope, and different membrane filters. The crater Zsigmondy on the Moon is named in his honour. Biography Early years Zsigmondy was born in Vienna, Austrian Empire, to a Hungarian gentry family. His mother Irma Szakmáry, a poet born in Martonvásár, and his father, Adolf Zsigmondy Sr., a scientist from Pressburg (Pozsony, today's Bratislava) who invented several surgical instruments for use in dentistry. Zsigmondy family members were Lutherans. They originated from Johannes () Sigmondi (1686–1746, Bártfa, Kingdom of Hungary) and included teachers, priests and Hungarian freedom-fighters. Richard was raised by his mother after his father's early death in 1880, and received a comprehensive education. He enjoyed hobbies such as ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electrical Double Layer
Electricity is the set of physical phenomena associated with the presence and motion of matter possessing an electric charge. Electricity is related to magnetism, both being part of the phenomenon of electromagnetism, as described by Maxwell's equations. Common phenomena are related to electricity, including lightning, static electricity, electric heating, electric discharges and many others. The presence of either a positive or negative electric charge produces an electric field. The motion of electric charges is an electric current and produces a magnetic field. In most applications, Coulomb's law determines the force acting on an electric charge. Electric potential is the work done to move an electric charge from one point to another within an electric field, typically measured in volts. Electricity plays a central role in many modern technologies, serving in electric power where electric current is used to energise equipment, and in electronics dealing with electrica ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Particle Size
Particle size is a notion introduced for comparing dimensions of solid particles ('' flecks''), liquid particles ('' droplets''), or gaseous particles ('' bubbles''). The notion of particle size applies to particles in colloids, in ecology, in granular material (whether airborne or not), and to particles that form a granular material (see also grain size). Measurement There are several methods for measuring particle size and particle size distribution. Some of them are based on light, other on ultrasound,Dukhin, A. S. and Goetz, P. J. ''Characterization of liquids, nano- and micro- particulates and porous bodies using Ultrasound'', Elsevier, 2017 or electric field, or gravity, or centrifugation. The use of sieves is a common measurement technique, however this process can be more susceptible to human error and is time consuming. Technology such as dynamic image analysis (DIA) can make particle size distribution analyses much easier. This approach can be seen in instruments ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Colloid
A colloid is a mixture in which one substance consisting of microscopically dispersed insoluble particles is suspended throughout another substance. Some definitions specify that the particles must be dispersed in a liquid, while others extend the definition to include substances like aerosols and gels. The term colloidal suspension refers unambiguously to the overall mixture (although a narrower sense of the word '' suspension'' is distinguished from colloids by larger particle size). A colloid has a dispersed phase (the suspended particles) and a continuous phase (the medium of suspension). The dispersed phase particles have a diameter of approximately 1 nanometre to 1 micrometre. Some colloids are translucent because of the Tyndall effect, which is the scattering of light by particles in the colloid. Other colloids may be opaque or have a slight color. Colloidal suspensions are the subject of interface and colloid science. This field of study began in 1845 by Franc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gelatin
Gelatin or gelatine () is a translucent, colorless, flavorless food ingredient, commonly derived from collagen taken from animal body parts. It is brittle when dry and rubbery when moist. It may also be referred to as hydrolyzed collagen, collagen hydrolysate, gelatine hydrolysate, hydrolyzed gelatine, and collagen peptides after it has undergone hydrolysis. It is commonly used as a gelling agent in food, beverages, medications, drug or vitamin capsules, photographic films, papers, and cosmetics. Substances containing gelatin or functioning in a similar way are called gelatinous substances. Gelatin is an irreversibly hydrolyzed form of collagen, wherein the hydrolysis reduces protein fibrils into smaller peptides; depending on the physical and chemical methods of denaturation, the molecular weight of the peptides falls within a broad range. Gelatin is present in gelatin desserts, most gummy candy and marshmallows, ice creams, dips, and yogurts. Gelatin for cooking comes ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Haemoglobin
Hemoglobin (haemoglobin, Hb or Hgb) is a protein containing iron that facilitates the transportation of oxygen in red blood cells. Almost all vertebrates contain hemoglobin, with the sole exception of the fish family Channichthyidae. Hemoglobin in the blood carries oxygen from the respiratory organs (lungs or gills) to the other tissues of the body, where it releases the oxygen to enable aerobic respiration which powers an animal's metabolism. A healthy human has 12to 20grams of hemoglobin in every 100mL of blood. Hemoglobin is a metalloprotein, a chromoprotein, and a globulin. In mammals, hemoglobin makes up about 96% of a red blood cell's dry weight (excluding water), and around 35% of the total weight (including water). Hemoglobin has an oxygen-binding capacity of 1.34mL of O2 per gram, which increases the total blood oxygen capacity seventy-fold compared to dissolved oxygen in blood plasma alone. The mammalian hemoglobin molecule can bind and transport up to four oxygen ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Albumin
Albumin is a family of globular proteins, the most common of which are the serum albumins. All of the proteins of the albumin family are water- soluble, moderately soluble in concentrated salt solutions, and experience heat denaturation. Albumins are commonly found in blood plasma and differ from other blood proteins in that they are not glycosylated. Substances containing albumins are called ''albuminoids''. A number of blood transport proteins are evolutionarily related in the albumin family, including serum albumin, alpha-fetoprotein, vitamin D-binding protein and afamin. This family is only found in vertebrates. ''Albumins'' in a less strict sense can mean other proteins that coagulate under certain conditions. See ' for lactalbumin, ovalbumin and plant "2S albumin". Function Albumins in general are transport proteins that bind to various ligands and carry them around. Human types include: * Human serum albumin is the main protein of human blood plasma. It m ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Potato Starch
Potato starch is starch extracted from potatoes. The cells of the root tubers of the potato plant contain leucoplasts (starch grains). To extract the starch, the potatoes are crushed, and the starch grains are released from the destroyed cells. The starch is then left to settle out of solution or separated by Hydrocyclone, hydrocyclones, then dried to powder. Potato starch contains typical large oval spherical granules ranging in size from 5 to 100 Micrometre, μm. Potato starch is a refined starch, containing minimal protein or fat. This gives the powder a clear white colour, and the cooked starch typical characteristics of neutral taste, good clarity, high binding strength, long texture, and minimal tendency to foaming or yellowing of the solution. Potato starch contains approximately 800 Parts per million, ppm phosphate bound to the starch; this increases the viscosity and gives the solution a slightly anionic character, a low starch gelatinization, gelatinisation temperat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
