Effects of ionic strength, monoethanolamine, copper, and pH on adsorption of alkyl dimethyl benzyl ammonium chloride in wood

Various factors were investigated that could affect the adsorption of alkyl dimethyl benzyl ammonium chloride (ADBAC) on red pine wood. An increase in ionic strength of ADBAC solution had little effect on ion exchange (chemisorption) but allowed higher hydrophobic uptake (physisorption) of ADBAC in wood. ADBAC solution containing high amounts of monoethanolamine (MEA) and Cu decreased the chemisorption of ADBAC; free MEA and Cu appear to compete with ADBAC cations for the same bonding sites in wood. When ADBAC in MEA solution was adsorbed on wood under different pH conditions, ADBAC adsorption increased with increasing pH, but was considerably lower than the cation exchange capacity of red pine. Red pine blocks were treated radially and longitudinally with alkaline copper quat solution to verify how the micelle form of ADBAC penetrates into wood. Copper penetrated evenly into 50 mm thick wood samples with little gradient with depth; however, high amounts of ADBAC were concentrated on the surface creating a steep gradient with depth. After accelerated leaching, considerable amounts of physically adsorbed ADBAC leached out, especially from the surface.