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  • silica gel
  • The most notable modification was the chemical bonding of alkane functional groups to silica gel to produce reversed-phase media. (wikipedia.org)
  • In this way (tedious though it may be) an octapeptide can be built onto the silica gel. (chromatography-online.org)
  • The reactions described are a meager sample of the many synthetic procedures that have been proposed and established for attaching a wide variety of organic groups to the silica gel surface. (chromatography-online.org)
  • Silica gel is a granular, vitreous, porous form of silicon dioxide made synthetically from sodium silicate. (wikipedia.org)
  • Silica gel contains a nano-porous silica micro-structure, suspended inside a liquid. (wikipedia.org)
  • Most applications of silica gel require it to be dried, in which case it is called silica xerogel. (wikipedia.org)
  • For practical purposes, silica gel is often interchangeable with silica xerogel. (wikipedia.org)
  • Silica gel is most commonly encountered in everyday life as beads in a small (typically 2 x 3 cm) paper packet. (wikipedia.org)
  • Since such packets may resemble sachets of sugar or salt and because silica gel may have added toxic chemical indicators (see below), silica gel packets usually bear warnings for the user not to eat the contents. (wikipedia.org)
  • Silica gel was in existence as early as the 1640s as a scientific curiosity. (wikipedia.org)
  • citation needed] The synthetic route for producing silica gel was patented by chemistry professor Walter A. Patrick at Johns Hopkins University in 1918. (wikipedia.org)
  • In World War II, silica gel was indispensable in the war effort for keeping penicillin dry, protecting military equipment from moisture damage[citation needed], as a fluid cracking catalyst for the production of high octane gasoline, and as a catalyst support for the manufacture of butadiene from ethanol, feedstock for the synthetic rubber program. (wikipedia.org)
  • Type C - translucent, micro-pored structure, raw material for preparation of silica gel cat litter. (wikipedia.org)
  • Additionally dried and screened, it forms macro-pored silica gel which is used as drier, adsorbent and catalyst carrier. (wikipedia.org)
  • Superficial polarity, thermal stability, performance greater than fine-pored silica gel. (wikipedia.org)
  • Stabilizing silica gel - non-crystalline micro-porous solid powder, nontoxic, flame-resisting, used in brewery of grains for beer to improve taste, clearness, color and foam, removal of non-micro-organism impurities. (wikipedia.org)
  • Silica gel is often described as "absorbing" moisture, which may be appropriate when the gel's microscopic structure is ignored, as in silica gel packs or other products. (wikipedia.org)
  • However, material silica gel removes moisture by adsorption onto the surface of its numerous pores rather than by absorption into the bulk of the gel. (wikipedia.org)
  • Some types of silica gel will "pop" when exposed to enough water. (wikipedia.org)
  • An aqueous solution of sodium silicate is acidified to produce a gelatinous precipitate that is washed, then dehydrated to produce colorless silica gel. (wikipedia.org)
  • When a visible indication of the moisture content of the silica gel is required, ammonium tetrachlorocobaltate(II) (NH4)2CoCl4 or cobalt chloride CoCl2 is added. (wikipedia.org)
  • Due to the connection between cancer and cobalt chloride, it has been forbidden in Europe on silica gel. (wikipedia.org)
  • Through the inclusion of silica gel packets, these items can be preserved longer. (wikipedia.org)
  • Silica gel may also be used to keep the relative humidity (RH) inside a high frequency radio or satellite transmission system waveguide as low as possible (see also Humidity buffering). (wikipedia.org)
  • It is common for a small compressed air system (similar to a small home aquarium pump) to be employed to circulate the air inside the waveguide over a jar of silica gel. (wikipedia.org)
  • Aqueous
  • Aqueous and polymer phases were used in the development of a novel partitioning scale. (wikipedia.org)
  • Its proton conductivity up to 0.2 S/cm depending on temperature and hydration state The solid phase and the aqueous phase of Nafion are both permeable to gases, which is a drawback for energy conversion devices such as artificial leaves, fuel cells, and water electrolyzers. (wikipedia.org)
  • Liquids
  • Both by weight and volume, gels are mostly fluid in composition and thus exhibit densities similar to those of their constituent liquids. (wikipedia.org)
  • particles
  • R&D in the field is driven by the realization that when the particle size is reduced to the point where critical length scales of physical phenomena become comparable to or larger than the particle size, the fundamental characteristics of these particles are very different from those of bulk materials. (mrs.org)
  • Unlike the lower concentrations where the arrangement of clay particles was continually in flux, the particles above 1% concentration locked into a stable structure which is known as equilbrium gel. (wikipedia.org)
  • Clay particles interact in an anisotropic way differing from the typical isotropic way of colloidal particles, which normally interact with all of their nearest neighbors when forming a gel. (wikipedia.org)
  • This lets clay particles connect in a chain and allows the gel to form at a low density. (wikipedia.org)
  • process
  • Here, after an overview of this technology, the current state of knowledge on the role of flame process variables (additives, mixing etc.) on the characteristics of product powders is summarized in a tutorial fashion. (mrs.org)
  • colloidal
  • Synthesis and processing of nanoparticles with controlled monodispersity and phase purity will require new aerosol, colloidal, thermal, chemical and physical vapor deposition approaches. (mrs.org)
  • Play media A hydrogel is a network of polymer chains that are hydrophilic, sometimes found as a colloidal gel in which water is the dispersion medium. (wikipedia.org)