| 1. |
- Cervin, Matti, et al.
(författare)
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Measuring misophonia in youth: A psychometric evaluation of child and parent measures
- 2023
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Ingår i: Journal of Affective Disorders. - 0165-0327. ; 338, s. 180-186
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Tidskriftsartikel (refereegranskat)abstract
- BackgroundMisophonia is characterized by intense emotional reactions to specific sounds or visual stimuli and typically onsets during childhood. An obstacle for research and clinical practice is that no comprehensively evaluated measures for pediatric misophonia exist.MethodsIn a sample of 102 youth meeting the proposed diagnostic criteria of misophonia, we evaluated the child and parent-proxy versions of the self-reported Misophonia Assessment Questionnaire (MAQ; assessing broad aspects of misophonia) and the child version of the Amsterdam Misophonia Scale (A-MISO-S; assessing misophonia severity). Confirmatory and exploratory factor analysis were used to examine factor structures of the measures. Further, child-parent agreement on the MAQ and associations between MAQ/A-MISO-S and impairment, quality of life, and misophonia-related school interference were examined to evaluate aspects of convergent validity.ResultsFor both youth- and parent-ratings, four MAQ factors emerged: pessimism, distress, interference, and non-recognition. A-MISO-S showed a unidimensional structure, but the item ‘effort to resist’ did not load significantly onto the unidimensional factor. Good child-parent agreement on the MAQ scales were found and both MAQ and A-MISO-S were moderately to strongly associated with misophonia-related impairment and school interference, and inversely associated with quality of life.LimitationsMAQ and A-MISO-S assess sensitivity to auditory but not visual stimuli, the sample size was modest, and repeated assessments were not conducted.ConclusionsThe combination of MAQ and A-MISO-S shows promise as a multidimensional assessment approach for pediatric misophonia. Future evaluations should include known-groups validity, screening performance, and sensitivity to change in symptom severity.
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| 2. |
- Cervin, Nicholas, et al.
(författare)
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Lightweight and strong cellulose materials made from aqueous foams stabilized by NanoFibrillated Cellulose (NFC)
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- A novel, lightweight and strong porous cellulose material has been prepared by drying aqueous foams stabilized with surface-modified NanoFibrillated Cellulose (NFC). This material differs from other particle stabilized foams in that we use renewable cellulose as stabilizing particle. Confocal microscopy and high speed video imaging show that the long-term stability of the wet foams can be attributed to the octylamine-coated, rod-shaped NFC nanoparticles residing at the air-liquid interface which prevent the air bubbles from collapsing or coalescing. This can be achieved at solids content around 1 % by weight. Careful removal of the water results in a cellulose-based material with a porosity of 98 % and a density of 30 mg cm-3. These porous cellulose materials have a higher Young’s modulus than other cellulose materials made by freeze drying and a compressive energy absorption of 56 kJ m-3 at 80 % strain. Measurement with the aid of an autoporosimeter revealed that most pores are in the range of 300 to 500 μm.
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| 3. |
- Cervin, Nicholas, 1982-
(författare)
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Porous Cellulose Materials from Nano Fibrillated Cellulose
- 2012
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Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- In the first part of this work a novel type of low-density, sponge-like material for the separation of mixtures of oil and water has been prepared by vapour deposition of hydrophobic silanes on ultra-porous nanocellulose aerogels. To achieve this, a highly porous (> 99 %) nanocellulose aerogel with high structural flexibility and robustness is first formed by freeze-drying an aqueous dispersion of the nanocellulose. The density, pore size distribution and wetting properties of the aerogel can be tuned by selecting the concentration of the nanocellulose dispersion before freeze-drying. The hydrophobic light-weight aerogels are almost instantly filled with the oil phase when they selectively absorb oil from water, with a capacity to absorb up to 45 times their own weight. The oil can also be drained from the aerogel and the aerogel can then be subjected to a second absorption cycle.In the second part of the work a novel, lightweight and strong porous cellulose material has been prepared by drying aqueous foams stabilized with surface-modified NanoFibrillated Cellulose (NFC). Confocal microscopy and high-speed video imaging show that the long-term stability of the wet foams can be attributed to the octylamine-coated, rod-shaped NFC nanoparticles residing at the air-liquid interface which prevent the air bubbles from collapsing or coalescing. Careful removal of the water yields a porous cellulose-based material with a porosity of 98 % and a density of 30 mg cm-3. These porous cellulose materials have a higher Young’s modulus than other cellulose materials made by freeze drying and a compressive energy absorption of 56 kJ m-3 at 80 % strain. Measurements with an autoporosimeter reveal that most pores are in the range of 300 to 500 μm.
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| 4. |
- Cervin, Nicholas Tchang, et al.
(författare)
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Mechanisms behind the Stabilizing Action of Cellulose Nanofibrils in Wet-Stable Cellulose Foams
- 2015
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Ingår i: Biomacromolecules. - : American Chemical Society (ACS). - 1525-7797 .- 1526-4602. ; 16:3, s. 822-831
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Tidskriftsartikel (refereegranskat)abstract
- The principal purpose of the investigation was to clarify the mechanisms behind the stabilizing action of cellulose nanofibrils (CNFs) in wet-stable cellulose foams. Following the basic theories for particle-stabilized foams, the investigation was focused on how the surface energy of the stabilizing CNF particles, their aspect ratio and charge density, and the concentration of CNF particles at the air-water interface affect the foam stability and the mechanical properties of a particle-stabilized air-liquid interface. The foam stability was evaluated from how the foam height changed over time, and the mechanical properties of the interface were evaluated as the complex viscoelastic modulus of the interface using the pendant drop method. The most important results and conclusions are that CNFs can be used as stabilizing particles for aqueous foams already at a concentration as low as 5 g/L. The major reasons for this were the small dimensions of the CNF and their high aspect ratio, which is important for gel-formation and the complex viscoelastic modulus of the particle-filled air-water interface. The influence of the aspect ratio was also demonstrated by a much higher foam stability of foams stabilized with CNFs than of foams stabilized by cellulose nanocrystals (CNC) with the same chemical composition. The charge density of the CNFs affects the level of liberation within larger aggregates and hence also the number of contact points at the interface and the gel formation and complex viscoelastic modulus of the air-water interface. The charges also result in a disjoining pressure related to the long-range repulsive electrostatic pressure between particle-stabilized bubbles and hence contribute to foam stability. (Figure Presented).
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| 5. |
- Cervin, Nicholas Tchang, et al.
(författare)
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Strong, Water-Durable, and Wet-Resilient Cellulose Nanofibril-Stabilized Foams from Oven Drying
- 2016
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Ingår i: ACS Applied Materials and Interfaces. - : American Chemical Society (ACS). - 1944-8244 .- 1944-8252. ; 8:18, s. 11682-11689
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Tidskriftsartikel (refereegranskat)abstract
- Porous materials from cellulose nanofibrils (CNFs) have been prepared using Pickering foams from aqueous dispersions. Stable wet foams were first produced using surface-modified CNFs as stabilizing particles. To better maintain the homogeneous pore structure of the foam after drying, the foams were dried in an oven on a liquid-filled porous ceramic frit. The cell structure was studied by scanning electron microscopy and liquid porosimetry, the mechanical properties were studied by compression testing, and the liquid absorption capacity was determined both with liquid porosimetry and by soaking in water. By controlling the charge density of the CNFs, it was possible to prepare dry foams with different densities, the lowest density being 6 kg m(-3), that is, a porosity of 99.6%. For a foam with a density of 200 kg m(-3) the compressive Young's modulus was 50 MPa and the energy absorption to 70% strain was 2.3 MJ M-3. The use of chemically modified CNFs made it possible to prepare cross-linked foams with water-durable and wet-resilient properties. These foams absorbed liquid up to 34 times their own weight and were able to release this liquid under compression and to reabsorb the same amount when the pressure was released.
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| 6. |
- Cervin, Nicholas Tchang, et al.
(författare)
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Ultra porous nanocellulose aerogels as separation medium for mixtures of oil/water liquids
- 2012
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Ingår i: Cellulose. - : Springer Science and Business Media LLC. - 0969-0239 .- 1572-882X. ; 19:2, s. 401-410
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Tidskriftsartikel (refereegranskat)abstract
- A novel type of sponge-like material for the separation of mixed oil and water liquids has been prepared by the vapour deposition of hydrophobic silanes on ultra-porous nanocellulose aerogels. To achieve this, a highly porous (> 99%) nanocellulose aerogel with high structural flexibility and robustness is first formed by freeze-drying an aqueous dispersion of the nanocellulose. The density, pore size distribution and wetting properties of the aerogel can be tuned by selecting the concentration of the nanocellulose dispersion before freeze-drying. The hydrophobic light- weight aerogels are almost instantly filled with the oil phase when selectively absorbing oil from water, with a capacity to absorb up to 45 times their own weight in oil. The oil can also be drained from the aerogel and the aerogel can then be reused for a second absorption cycle.
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| 7. |
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| 8. |
- Guzick, Andrew, et al.
(författare)
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Clinical characteristics, impairment, and psychiatric morbidity in 102 youth with misophonia
- 2022
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Ingår i: Journal of Affective Disorders. - : Elsevier BV. - 0165-0327. ; 324, s. 395-402
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Tidskriftsartikel (refereegranskat)abstract
- BackgroundThere is little information on the clinical presentation, functional impact, and psychiatric characteristics of misophonia in youth, an increasingly recognized syndrome characterized by high emotional reactivity to certain sounds and associated visual stimuli.MethodOne-hundred-two youth (8–17 years-old) with misophonia and their parents were recruited and compared with 94 youth with anxiety disorders. Participants completed validated assessments of misophonia severity, quality of life, as well as psychiatric symptoms and diagnoses.ResultsThe most common misophonia triggers included eating (96 %), breathing (84 %), throat sounds (66 %), and tapping (54 %). Annoyance/irritation, verbal aggression, avoidance behavior, and family impact were nearly universal. Misophonia severity was associated with internalizing symptoms, child-reported externalizing behaviors, and poorer quality of life. High rates of comorbidity with internalizing and neurodevelopmental disorders were found. Quality of life and externalizing behaviors were not significantly different between misophonia and anxiety samples; internalizing symptoms and autism characteristics were significantly higher among youth with anxiety disorders.LimitationsThis self-selected sample was characterized by limited multicultural diversity.ConclusionsThis study presents misophonia as a highly impairing psychiatric syndrome. Future interdisciplinary work should clarify the mechanisms of misophonia, establish evidence-based treatments, and extend these findings to randomly sampled and more culturally diverse populations.
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| 9. |
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| 10. |
- Murphy, Nicholas, et al.
(författare)
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Alterations in attentional processing in youth with misophonia: A phenotypical cross-comparison with anxiety patients
- 2024
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Ingår i: Journal of Affective Disorders. - 0165-0327. ; 347, s. 429-436
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Tidskriftsartikel (refereegranskat)abstract
- BackgroundMisophonia is a complex condition characterized by extreme emotional distress in response to specific sounds or specific visual stimuli. Despite a growing body of clinical and neuroscientific literature, the etiology of this condition remains unclear. Hyperarousal, that is, a state of heightened alertness and disinhibition, as a core feature of misophonia is supported by behavioral and neuroimaging literature and might represent a viable clinical target for the development of both behavioral and pharmacological interventions. The aim of this study was to investigate how hyperarousal might be linked to neurocognitive processes associated with vigilance and stimulus discrimination in youth with misophonia.MethodsWe compared 72 children and adolescents with misophonia (13.74 ± 2.44 years) (64 % female) and 89 children and adolescents with anxiety (12.35 ± 2.57 years) (58.4 % female) on behavioral and signal detection performance of the immediate memory task (IMT). Anxiety patients were used as a clinical control group to distinguish attentional processes specific for misophonia.ResultsBoth groups demonstrated similar behavioral performance, including response rate and reaction time. However, misophonia was associated with elevated stimulus discrimination (d prime), which in turn was positively correlated with the severity of misophonia trigger reports.ConclusionsOur findings are in line with previous cognitive and neuroimaging studies, and support an arousal-based model of misophonia, where individuals with misophonia experience a state of heightened vigilance, being more aware of stimuli in the environment. Our findings provide a neurocognitive basis for future study of neurochemical imaging that might further progress towards clinical targets.
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| 11. |
- Mushi, Ngesa Ezekiel Zekiel, et al.
(författare)
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Nanostructurally Controlled Hydrogel Based on Small-Diameter Native Chitin Nanofibers : Preparation, Structure, and Properties
- 2016
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Ingår i: ChemSusChem. - : Wiley-VCH Verlagsgesellschaft. - 1864-5631 .- 1864-564X.
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Tidskriftsartikel (refereegranskat)abstract
- Chitin nanofibers of unique structure and properties can be obtained from crustacean and fishery waste. These chitin nanofibers have roughly 4nm diameters, aspect ratios between 25-250, a high degree of acetylation and preserved crystallinity, and can be potentially applied in hydrogels. Hydrogels with a chitin nanofiber content of 0.4, 0.6, 0.8, 1.0, 2.0, and 3.0wt% were successfully prepared. The methodology for preparation is new, environmentally friendly, and simple as gelation is induced by neutralization of the charged colloidal mixture, inducing precipitation and secondary bond interaction between nanofibers. Pore structure and pore size distributions of corresponding aerogels are characterized using auto-porosimetry, revealing a substantial fraction of nanoscale pores. To the best of our knowledge, the values for storage (13kPa at 3wt%) and compression modulus (309kPa at 2wt%) are the highest reported for chitin nanofibers hydrogels.
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| 12. |
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| 13. |
- Storch, Eric A, et al.
(författare)
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Family Accommodation in Children and Adolescents with Misophonia
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Ingår i: Behavior Therapy. - 1878-1888.
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Tidskriftsartikel (refereegranskat)abstract
- Family accommodation (e.g., reassurance, modifying routines, assisting avoidance) has not been explored among youth with misophonia but may have important clinical and intervention implications. We examined family accommodation in 102 children and adolescents with interview-confirmed misophonia and compared its frequency and content to family accommodation in 95 children and adolescents with anxiety disorders. Findings showed that family accommodation was ubiquitous in pediatric misophonia and may be even more frequent than in youth with anxiety disorders. Assisting the child, participating in misophonia-related behaviors, and modifying family routines were endorsed by more than 70% of parents of children with misophonia. Further, compared to parents of children with anxiety disorders, parents of children with misophonia more frequently reported child distress and anger when they did not accommodate. Family accommodation was a moderate to strong predictor of misophonia severity even when accounting for co-occurring internalizing and externalizing symptoms and sociodemographic factors. This first study of family accommodation in pediatric misophonia suggests accommodation may be an important clinical feature oand a potential candidate to target in interventions.
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| 14. |
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| 15. |
- Tchang Cervin, Nicholas, 1982-, et al.
(författare)
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Lightweight and Strong Cellulose Materials Made from Aqueous Foams Stabilized by Nanofibrillated Cellulose
- 2013
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Ingår i: Biomacromolecules. - : American Chemical Society (ACS). - 1525-7797 .- 1526-4602. ; 14:2, s. 503-511
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Tidskriftsartikel (refereegranskat)abstract
- A lightweight and strong porous cellulose material has been prepared by drying aqueous foams stabilized with surface-modified nanofibrillated cellulose (NFC). This material differs from other dry, particle stabilized foams in that renewable cellulose is used as stabilizing particles. Confocal microscopy and high speed video imaging show that the octylamine-coated, rod-shaped NFC nanoparticles residing at the air-liquid interface prevent the air bubbles from collapsing or coalescing. Stable wet foams can be achieved at solids content around 1% by weight. Careful removal of the water results in a cellulose-based material with a porosity of 98% and a density of 30 mg cm(-3). These porous cellulose materials have a higher Young's modulus than porous cellulose materials made from freeze-drying, at comparable densities, and have a compressive energy absorption of 56 kJ m(-3) at 80% strain. Measurement with the aid of an autoporosimeter revealed that most pores are in the range of 300 to 500 mu m.
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| 16. |
- Tchang Cervin, Nicholas, 1982-
(författare)
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NFC Stabilized Foam
- 2013
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Patent (populärvet., debatt m.m.)
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| 17. |
- Tchang Cervin, Nicholas, 1982-
(författare)
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Porous Materials from Cellulose Nanofibrils
- 2014
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- In the first part of this work a novel type of low-density, sponge-like material for the separation of mixtures of oil and water has been prepared by vapour deposition of hydrophobic tri-chloro-silanes on ultra-porous cellulose nanofibril (CNF) aerogels. To achieve this, a highly porous (>99%) robust CNF aerogel with high structural flexibility is first formed by freeze-drying an aqueous suspension of the CNFs. The density, pore size distribution and wetting properties of the aerogel can be tuned by selecting the concentration of the CNF suspension before freeze-drying. The hydrophobic light-weight aerogels are almost instantly filled with the oil phase when they selectively absorb oil from water, with a capacity to absorb up to 45 times their own weight. The oil can subsequently be drained from the aerogel and the aerogel can then be subjected to a second absorption cycle.The second part is about aerogels with different pore structures and manufactured with freeze-drying and supercritical carbon dioxide for the preparation of super slippery surfaces. Tunable super slippery liquid-infused porous surfaces (SLIPS) were fabricated through fluorination of CNFsand subsequent infusion with perfluorinated liquid lubricants. CNF-based self-standing membranes repelled water and hexadecane with roll-off angles of only a few degrees. The lifetime of the slippery surface was controlled by the rate of evaporation of the lubricant, where the low roll-off angle could be regained with additional infusion. Moreover, adjusting the porosity of the membranes allowed the amount of infused lubricant to be tuned and thereby the lifetime. The CNF-based process permitted the expansion of the concept to coatings on glass, steel, paper and silicon. The lubricant-infused films and coatings are optically transparent and also feature self-cleaning and self-repairing abilities.The third part describes how porous structures from CNFs can be prepared in a new way by using a Pickering foam technique to create CNF-stabilized foams. This technique is promising for up-scaling to enable these porous nanostructured cellulose materials to be produced on a large scale. With this technique, a novel, lightweight and strong porous cellulose material has been prepared by drying aqueous foams stabilized with surface-modified CNFs. Confocal microscopy and high-speed video imaging show that the long-term stability of the wet foams can be attributed to the octylamine-coated, rod-shaped CNF nanoparticles residing at the air-liquid interface which prevent the air bubbles from collapsing or coalescing. Careful removal of the water yields a porous cellulose-based material with a porosity of 98 %, and measurements with an autoporosimeter (APVD) reveal that most pores have a radius in the range of 300 to 500 μm.In the fourth part, the aim was to clarify the mechanisms behind the stabilizing action of CNFs in wet-stable cellulose foams. Factors that have been investigated are the importance of the surface energy of the stabilizing CNF particles, their aspect ratio and charge density, and the concentration of CNF particles at the air-water interface. In order to investigate these parameters, the viscoelastic properties of the interface have been evaluated using the pendant drop method. The properties of the interface have also been compared by foam stability tests to clarify how the interface properties can be related to the foam stability over time. The most important results and conclusions are that CNFs can be used as stabilizing particles for aqueous foams already at a concentration as low as 5 g/L. The reasons for this are the high aspect ratio which is important for gel formation and the viscoelastic modulus of the air-water interface. Foams stabilized with CNFs are therefore much more stable than foams stabilized by cellulose nanocrystals (CNC). The charge density of the CNFs affects the level of liberation of the CNFs within large CNF aggregates and hence the number of contact points at the interface, and also the gel formation and viscoelastic modulus. The charges also lead to a disjoining pressure related to the long-range repulsive electrostatic interaction between the stabilized bubbles, and this contributes to foam stability.In the fifth part, the aim was to develop the drying procedure in order to producea dry porous CNF material using the wet foam as a precursor and to evaluate the dry foam properties. The wet foam was dried in an oven while placed on a liquid-filled porous ceramic frit to preserve and enhance the porous structure in the dried material and prevent the formation of larger cavities and disruptions. The cell structure has been studied by SEM microscopy and APVD (automatic pore volume distribution). The mechanical properties have been studied by a tensile tester (Instron 5566) and the liquid absorption ability with the aid of the APVD-equipment. By changing the charge density of the CNFs it is possible to prepare dry foams with different densities and the lowest density was found to be 6 kg m-3with a porosity of 99.6 %. The Young ́s modulus in compression was 50 MPa and the energy absorption was 2340kJ m-3 for foams with a density of 200 kg m-3. The liquid absorption of the foam with a density of 13 kg m-3 is 34 times its own weight. By chemically cross-linking the foam,it wasalso possible to empty the liquid-filled foams by compression and then to reabsorb the liquid to the same degree with maintained foam integrity. This new processing method also shows great promise for preparing low-density cellulose foams continuously and could be very suitable for industrial up-scaling.
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| 18. |
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| 19. |
- Wågberg, Lars, 1956-, et al.
(författare)
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Pickering foams from cellulose nanofibrils
- 2015
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Ingår i: Abstracts of Papers of the American Chemical Society. - : AMER CHEMICAL SOC. - 0065-7727. ; 249
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)
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