title: Temperature stability of nanocellulose dispersions.
abstract: Cellulose nanofibrils (CNF) have potential as rheology modifiers of water based fluids, e.g. drilling fluids for use in oil wells or as additives in injection water for enhanced oil recovery (EOR). The temperature in oil wells can be high (>100°C), and the retention time long; days for drilling fluids and months for EOR fluids. Hence, it is important to assess the temperature stability over time of nanocellulose dispersions to clarify their suitability as rheology modifiers of water based fluids at such harsh conditions. Dispersions of CNF produced mechanically, by using TEMPO mediated oxidation and by using carboxymethylation as pretreatment, in addition to cellulose nanocrystals (CNC), have been subjected to heat aging. Temperature stability was best for CNC and for mechanically produced CNF that were stable after heating to 140°C for three days. The effect of additives was evaluated; cesium formate and sodium formate increased the temperature stability of the dispersions, while there was no effect of using phosphate buffer.
authors.affiliation: Paper and Fibre Research Institute (PFI), Høgskoleringen 6b, NO-7491 Trondheim, Norway. Electronic address: ellinor.heggset@pfi.no.
authors.forename: Ellinor B
authors.initials: EB
authors.lastname: Heggset
authors.affiliation: Paper and Fibre Research Institute (PFI), Høgskoleringen 6b, NO-7491 Trondheim, Norway. Electronic address: gary.chinga.carrasco@pfi.no.
authors.forename: Gary
authors.initials: G
authors.lastname: Chinga-Carrasco
authors.affiliation: Paper and Fibre Research Institute (PFI), Høgskoleringen 6b, NO-7491 Trondheim, Norway; Norwegian University of Science and Technology (NTNU), Department of Chemical Engineering, NO-7491 Trondheim, Norway. Electronic address: kristin.syverud@pfi.no.
authors.forename: Kristin
authors.initials: K
authors.lastname: Syverud
keywords: Cellulose nanocrystals; Cellulose nanofibrils; Cesium formate (PubChem CID: 23663999); Drilling fluids; Enhanced oil recovery; Furfural (PubChem CID: 7362); Hydroxymethylfurfural (PubChem CID: 237332); Rheology; Sodium chlorite (PubChem CID: 23668197); Sodium formate (PubChem CID: 2723810); Sodium hypochlorite (PubChem CID: 23665760); Temperature stability