Rheology and Filtration Properties of Bentonite-Water Suspensionsas Influenced by Lignocellulosic Nanomaterials and Water-SolubleBiopolymer Additives

Stability, structural morphology, and rheological andfiltration proper-ties of bentonite (BT)-water suspensions as influenced by the addition oflignocellulosic nanomaterials, including bleached nanofibrillated cellulose (NFC)and lignin-containing NFC (LNFC), and water-soluble polymers (WSPs) wereinvestigated in this work. The performance of the formedfluids varied with the distinctfiber morphology and/or chemical composition of the NFC and LNFC. The NFChelped bridge BT particles for enhanced rheological performance but adverselyaffectedfiltration properties by forming thickerfilter cakes. Reground NFC led toimproved rheological properties owing to more individualizedfibers with an enlarged surface area, but its effect onfluid loss wasinsignificant. LNFC enhanced viscosity, yield stress, and gelation properties of thefluid with effectiveness varying with the actuallignin content in the system. Enhancedfiltration performance was seen with the presence of lignin in LNFC ascribed by itshydrophobic nature as well as the formation of more compactfilter cakes. The applied biopolymers depicted better compatibilitywith smaller cellulosicfibril dimensions and lower lignin content. Thus, LNFC with moderate amounts of lignin in combination withbiopolymer additives can help achieve much-improved rheological andfiltration performance of BT-basedfluids with lower cost andmore environmental friendliness

Automated summary

This study investigated the effects of lignocellulosic nanomaterials and water-soluble polymers on the properties of bentonite-water suspensions. The results showed that nanofibrillated cellulose (NFC) improved rheological performance but adversely affected filtration properties, while reground NFC improved rheological properties without significant effect on fluid loss. Lignin-containing NFC (LNFC) enhanced viscosity and filtration performance. LNFC with moderate amounts of lignin, in combination with biopolymer additives, can significantly improve the rheological and filtration performance of BT-based fluids.