Glossary, Acronyms and Abbreviations The following words listed in bold are written in italic in the contributions A A H2O/Na2SiO3 molar ratio A23187 Calcium ionophore Absorption In chemistry, the process by which one substance, such as a solid or liquid, takes up another substance, such as a liquid or gas, through minute pores or spaces between its molecules. In physics, the process in which the incident radiated energy is retained without reflection or transmission on passing through a medium ACC Aerogel Cherenkov Counter Acidity Acid strength AC-ML Aerogel composite acoustic matching layer Acoustic impedance Ratio of particle velocity and the sound pressure Acoustic matching layer Antireflective layer of acoustic wave Acoustic velocity Velocity v of an acoustic wave as it travels across a solid, a liquid, a gas or a mixed material medium ADP Adenosine di-phosphate, a product which can be used to induce platelet aggregation Adsorption Surface phenomenon by which molecules of a gas or a liquid are fixed on the surface of a solid, with various types of bonding Adsorption isotherms Adsorption is usually described through isotherms, i.e., the amount of adsorbate on the adsorbent as a function of its pressure (if gas) or concentration (if liquid) at constant temperature Aerobic oxidation Oxidation by air under ambient conditions Aerocellulose Aerogels made from cellulose Aeroclay Aeroclays are clay-based aerogels generally elaborated by freeze-drying of clay-based hydrogels (for example, gels prepared with sodium-exchanged montmorillonite clay). It is accepted that the freeze-drying step results in a rearrangement of clay sheets to create the lightweight, oriented and porous structure of the final clay-based aerogel Aerocore An organic monolithic panel manufactured by American Aerogel Corporation Aerogels Defined by IUPAC as “Gels comprised of a microporous solid in which the dispersed phase is a gas” [see Pure Appl. Chem. 79(10):1801–1809, 2007]. However, the definition retained in this handbook is the one by Kistler, as “gels in which the liquid has been replaced by air, with very moderate shrinkage of the solid network” Aerogel functionalization Implementation of functional groups into aerogels AeroSand Sand bonded by aerogels M.A. Aegerter et al. (eds.), Aerogels Handbook, Advances in Sol-Gel Derived 893 Materials and Technologies, DOI 10.1007/978-1-4419-7589-8, # Springer Science+Business Media, LLC 2011 894 Glossary, Acronyms and Abbreviations Aerosculpture Word invented by the author I. Michaloudis, from air and sculpture. A pair of parenthesis – as a personal symbol of an open “space in between” – replaces the letter o and gives the visual word aer()sculpture Aerosol Suspension of colloidal solid particles or liquid droplets in a gas, such as air AFM Atomic force microscopy Ageing (or Aging) Experiment where a material is maintained for a certain time in constant environment conditions and its characteristics are slowly changing with time. Specifically speaking with gels, ageing is a curing period where gels are immerged in a specific liquid media where ageing mechanisms (generally, syneresis and/or Ostwald ripening) are promoted or frozen AIBN Azobisisobutyronitrile Alcogel A wet gel containing alcohol formed by sol-gel method ALD Atomic layer deposition Alkoxide Sol-gel precursor of chemical formula M(OR)n, where M designates a cation, R an alkyl group and OR an alkoxide group. Alkoxides are often available, in a more or less polymerized form, in solution in their parent alcohol (for example ethanol for TEOS or methanol for TMOS) Allophane Allophane is an amorphous clay from natural soil; it is a natural alumino- silicate originating from the transformation of volcanic ashes and glasses with weathering. Allophane exists for young volcanic soil and is progressively transformed into crystalline clays, halloysite, then into kaolinite Ambigels Gels dried by evaporation of their liquid with moderate shrinkage. Ambigels are considered as “aerogels” and sometimes termed “ambient pressure drying aerogels,” when their shrinkage is moderate and their specific pore volume high Ambient pressure drying Drying of gels by evaporation of their liquid with moderate shrinkage in room temperature and pressure conditions Amorphous material An “amorphous material” is a solid in which there is no long-range order of the positions of the atoms AN Ammonium nitrate Analyte The chemical species being analyzed Anaphylatoxins A toxic substance formed in the blood that is associated with bacterial polysaccharides Anthropogenic A process that results from human activity AP Aerogel powder and/or particles APD Ambient pressure drying. See also Ambigels Apparent thermal conductivity Thermal conductivity value assigned to a material that exhibits thermal transmission by at least one nondiffusive mode of heat transfer resulting in property variation with specimen thickness, or surface emittance APTES 3-Aminopropyltriethoxysilane Arrhenius law Expression describing the exponential dependence of a reaction on an activation energy ASCE Alcohol supercritical extraction ASTM American Society for Testing and Materials Attenuation length L (optical) The distance traveled across in an aerogel, where the probability that a photon has not been absorbed has dropped by 1/e (where e ¼ 2.71828) AZC Aerogel sulfated zirconia doped with cerium AZS Aerogel sulfated zirconia AZSCr Aerogel sulfated zirconia doped with chromium Glossary, Acronyms and Abbreviations 895 B BCAM Base-catalyzed, acid-modified bcc Body centered cubic structure Bending strength Strength of a material tested in a bending test most often using rectangular bars supported by two racks separated by a fixed distance. A bar is subjected in the middle by a force and bends thereby. The fracture strength is calculated from the maximum force and the geometry of the test bar BESS Balloon-borne experiment with a superconducting spectrometer BET Evaluation method named after Brunauer, Emmett, and Teller to obtain the surface area from adsorption isotherms due to a theory for multilayer adsorption BF Bright field Binder A material bonding together e.g., sand grains, very often a polymer or colloidal sodium silicate Biomimicry From bios, meaning life, and mimesis, meaning to imitate: It is an ancient concept recently returning to scientific thought that examines nature, its models, systems, processes, and elements – and emulates or takes inspiration from them to solve human problems sustainably. Scientific and engineering literature often uses the term biomimetics for the process of understanding and applying biological principles to human designs Biosensor see “Sensors (biochemical)” BJH Barret, Joyner, and Halenda who developed a methodology to determine the pore volume distribution from nitrogen adsorption isotherms using the Kelvin equation, relating the capillary pressure to pore size via the interfacial tension of a fluid condensing in a capillary BMH Born–Mayer–Huggins model for silicon dioxide, an empirical potential consisting of pairwise-additive repulsive terms and Coulombic interactions BO Bridging oxygen Bolus release Administration of a drug over a relatively quick amount of time (less than 5 min) in comparison to a sustained delivery which can last over hours Bonding bridge Bridge between two sand grains made up by a polymer or an aerogel Bronsted€ acidity Chemical compound presenting Bronsted€ acid sites that are able to lose a proton Bridgman furnace A furnace with at least three zones being at different temperatures. A hot zone and a cold zone are separated by an adiabatic zone. Directional solidification or crystal growth is achieved by either pulling the sample through the furnace from hot to cold or by moving the furnace Brittle fracture Fracture of a material being completely elastically stressed (no irreversible plastic deformation) BSA Bovine serum albumin BSE Backscattered electrons BTAC Benzyltrimethylammoniumchloride BTMSH 1,6-Bis(trimethoxysilyl)hexane BTMSPA Bis(trimethoxysilyl-propyl) amine Bulk-modified Sol–gel material prepared by adding probe to the precursor mixture (also known as predoped) C C3a A plasma inflammation marker (plasma anaphylatoxin generation) which is part of the complement pathway. C3a is the released degradation product of C3 (complement component 3) 896 Glossary, Acronyms and Abbreviations C5a A plasma inflammation marker (plasma anaphylatoxin generation) which is part of the complement pathway. C5a is the released degradation product of C5 (complement component 5) Capillary Tube of small internal diameter, typically of the order of a few mm or less, in which liquids can raise spontaneously, when one end of the tube is dipped in these liquids Capillary stresses Mechanical stresses due to surface interaction of a liquid with a capillary and the presence of a gas–liquid meniscus in a capillary pore, responsible for the liquid raise in such capillary Carbon aerogel Aerogel obtained by pyrolysis of an organic (polymeric) aerogel under protective atmosphere Carbon AeroSand Sand bonded by carbon aerogels Carman–Kozeny equation This equation is empirical and relates the permeability ¼ð À r Þ 2= r to the pore size and pore volume:D 1 r rw 4Kwwhere r is the relative density, rw is the hydraulic radius and Kw is the so-called the Kozeny constant close to 5 CARS Coherent anti-Stokes Raman scattering Cavitation Creation of cavities within a liquid or solid caused by the propagation of a pressure wave through this liquid or solid. It may also mean the formation of vaporous bubbles in