Litmus "Lecanora tartarea" (Norway, Sweden), "Variolaria dealbata", "Ochrolechia parella", "Parmotrema tinctorum", and "Parmelia". Currently, the main sources are "Roccella montagnei" (Mozambique) and "Dendrographa leucophoea" (California). The main use of litmus is to test whether a solution is acidic or basic. Wet litmus paper can also be used to test for water-soluble gases that affect acidity or alkalinity; the gas dissolves in the water and the resulting solution colors the litmus paper. For instance, ammonia gas, which is alkaline, turn the red litmus paper blue. Blue litmus paper turns red under acidic conditions and red litmus paper turns blue under basic or
Chemistry of biofilm prevention stabilization of colloids. Polymer chains are grafting to a surface via covalent bonding or adsorption. The solubility of these polymers stems from the high conformational entropy of polymer chains in solution. The Χ (Chi) parameter is used to determine whether a polymer will be soluble in a given solution. Χ is given by the equation: where formula_6 and formula_7 are the cohesive energy densities of the polymer and solvent, respectively, formula_8 is the molar volume of the solution (assuming formula_9), R is the ideal gas constant, and T is temperature in Kelvins. If 0 < formula_10< 2, the polymer will