RT Journal Article T1 Efficiency of chitosan and their combination with bentonite as retention aids in papermaking A1 Miranda Carreño, Rubén A1 Nicu, Raluca A1 Bobu, Elena A1 Blanco Suárez, María Ángeles AB In a previous work (Nicu et al. 2013), the flocculation efficiency of three chitosans differing by molecular weight and charge density were evaluated for their potential use as wet end additives in papermaking. According to the promising results obtained, chitosan (single system) and its combination with bentonite (dual system) were evaluated as retention aids, and their efficiency was compared with poly(diallyl dimethyl ammonium chloride) (PDADMAC) and polyethylenimine (PEI). In single systems, chitosan was clearly more efficient in drainage rate than PDADMAC and PEI, especially those with the lowest molecular weights; however, retention is considerably lower. This drawback can be overcome by using dual systems with anionic bentonite microparticles, with the optimum ratio of polymer:bentonite being 1:4 (wt./wt.). In dual systems, the differences in retention were almost negligible, and the difference in drainage rate was even higher, together with better floc reversibility. The most efficient chitosan in single systems was Ch.MMW, while Ch.LMW was the most efficient in dual systems. The flocculation mechanism of chitosan was a combination of patch formation, charge neutralization, and partial bridge formation, and the predominant mechanism depended on the molecular weight and charge density of the chitosan. PB Dept. of Wood and Paper Science, College of Natural Resources, North Carolina State University SN 1930-2126 YR 2016 FD 2016 LK https://hdl.handle.net/20.500.14352/18995 UL https://hdl.handle.net/20.500.14352/18995 LA eng NO Miranda, Ruben, et al. «Efficiency of Chitosan and their Combination with Bentonite as Retention Aids in Papermaking». BioResources, vol. 11, n.o 4, octubre de 2016, pp. 10448-68. DOI.org (Crossref), https://doi.org/10.15376/biores.11.4.10448-10468. NO European Commission NO Comunidad de Madrid DS Docta Complutense RD 21 abr 2025