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1	Strong and Flexible TEMPO-CNF/Boron Nitride Nanocomposite Films / Starka och flexibla nanokompositfilmer av TEMPO-CNF/boronnitrid Sadatifard, Sara January 2023 (has links) Nanokompositfilmer med fem olika sammansättningar av hexagonala bornitrid nanosheet och TEMPO-CNF tillverkades med hjälp av vakuumassisterad filtreringsteknik. sond-ultraljudsteknik användes som en grön väg för exfoliering av bornitridpulver i vattenhaltigt medium. TEMPO-CNF spelade nyckelroller som både matris och dispergeringsmedel för stabilisering av bornitrid nanosheets i kompositen. Nanokompositfilmerna var flexibla och formbara och de visade höga mekaniska egenskaper inklusive hög draghållfasthet och god brottöjning. / Nanocomposite films with five different compositions of hexagonal boron nitride nanosheets and TEMPO-CNF were fabricated using vacuum-assisted filtration technique. probe-ultrasonication technique was applied as a green route for exfoliation of boron nitride powder in aqueous medium. TEMPO-CNF played key roles as both matrix and dispersant agent for stabilization of the boron nitride nanosheets in the composite. The nanocomposite films were flexible and ductile, and they showed high mechanical properties including high tensile strength and good elongation at break. Hexagonal boron nitride cellulose nanofibrils mechanical properties nanocomposite thermal conductivity Hexagonal bornitrid cellulose nanofibrillar mekaniska egenskaper nanokomposit värmeledningsförmåga Composite Science and Engineering Kompositmaterial och -teknik
2	Microfibrillated cellulose: Energy-efficient preparation techniques and applications in paper Ankerfors, Mikael January 2015 (has links) This work describes three alternative processes for producing microfibrillated cellulose (MFC; also referred to as cellulose nanofibrils, CNF) in which bleached pulp fibres are first pretreated and then homogenized using a high-pressure homogenizer. In one process, fibre cell wall delamination was facilitated by a combined enzymatic and mechanical pretreatment. In the two other processes, cell wall delamination was facilitated by pretreatments that introduced anionically charged groups into the fibre wall, by means of either a carboxymethylation reaction or irreversibly attaching carboxymethylcellulose (CMC) to the fibres. All three processes are industrially feasible and enable energy-efficient production of MFC. Using these processes, MFC can be produced with an energy consumption of 500–2300 kWh/tonne. These materials have been characterized in various ways and it has been demonstrated that the produced MFCs are approximately 5–30 nm wide and up to several microns long. The MFCs were also evaluated in a number of applications in paper. The carboxymethylated MFC was used to prepare strong free-standing barrier films and to coat wood-containing papers to improve the surface strength and reduce the linting propensity of the papers. MFC, produced with an enzymatic pretreatment, was also produced at pilot scale and was studied in a pilot-scale paper making trial as a strength agent added at the wet-end for highly filled papers. / <p>QC 20150126</p> Microfibrillated cellulose microfibrillar cellulose nanofibrillated cellulose nanofibrillar cellulose cellulose nanofibrils nanocellulose MFC NFC CNF production techniques energy efficient gel properties films enzymes carboxymethylation carboxymethyl cellulose CMC mechanical properties oxygen barrier homogenization linting papermaking
3	Microfibrillated cellulose : Energy-efficient preparation techniques and key properties Ankerfors, Mikael January 2012 (has links) This work describes three alternative processes for producing microfibrillated cellulose (MFC) in which pulp fibres are first pre-treated and then homogenized using a high-pressure homogenizer. In one process, fibre cell wall delamination was facilitated with a combined enzymatic and mechanical pre-treatment. In the two other processes, cell wall delamination was facilitated by pre-treatments that introduced anionically charged groups into the fibre wall, by means of either a carboxymethylation reaction or irreversibly attaching carboxymethyl cellulose (CMC) onto the fibres. All three processes are industrially feasible and enable production with low energy consumption. Using these methods, MFC can be produced with an energy consumption of 500–2300 kWh/tonne, which corresponds to a 91–98% reduction in energy consumption from that presented in earlier studies. These materials have been characterized in various ways and it has been demonstrated that the produced MFCs are approximately 5–30 nm wide and up to several microns long. / <p>QC 20120928</p> Microfibrillated cellulose microfibrillar cellulose nanocellulose MFC NFC production techniques energy efficient gel properties films enzymes carboxymethylation carboxymethyl cellulose CMC mechanical properties oxygen barrier homogenization Paper, Pulp and Fiber Technology Pappers-, massa- och fiberteknik

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