Change search
Link to record
Permanent link

Direct link
Publications (10 of 58) Show all publications
Eriksson, M., Claesson, P. M., Järn, M., Wallqvist, V., Tuominen, M., Kappl, M., . . . Swerin, A. (2024). Effects of Gas Layer Thickness on Capillary Interactions at Superhydrophobic Surfaces. Langmuir, 40(9), 4801-4810
Open this publication in new window or tab >>Effects of Gas Layer Thickness on Capillary Interactions at Superhydrophobic Surfaces
Show others...
2024 (English)In: Langmuir, ISSN 0743-7463, E-ISSN 1520-5827, Vol. 40, no 9, p. 4801-4810Article in journal (Refereed) Published
Abstract [en]

Strongly attractive forces act between superhydrophobic surfaces across water due to the formation of a bridging gas capillary. Upon separation, the attraction can range up to tens of micrometers as the gas capillary grows, while gas molecules accumulate in the capillary. We argue that most of these molecules come from the pre-existing gaseous layer found at and within the superhydrophobic coating. In this study, we investigate how the capillary size and the resulting capillary forces are affected by the thickness of the gaseous layer. To this end, we prepared superhydrophobic coatings with different thicknesses by utilizing different numbers of coating cycles of a liquid flame spraying technique. Laser scanning confocal microscopy confirmed an increase in gas layer thickness with an increasing number of coating cycles. Force measurements between such coatings and a hydrophobic colloidal probe revealed attractive forces caused by bridging gas capillaries, and both the capillary size and the range of attraction increased with increasing thickness of the pre-existing gas layer. Hence, our data suggest that the amount of available gas at and in the superhydrophobic coating determines the force range and capillary growth. © 2024 The Authors.

Place, publisher, year, edition, pages
American Chemical Society, 2024
Keywords
Coatings; Flame spraying; Hydrophobicity; Molecules; Sols; Surface properties; water; Attractive force; Capillary force; Capillary interactions; Coating cycles; Different thickness; Gas layers; Gas molecules; Layer thickness; Super-hydrophobic surfaces; Superhydrophobic coatings; adult; article; capillary; confocal laser scanning microscopy; flame; gas; liquid; middle aged; thickness; Gases
National Category
Chemical Sciences
Identifiers
urn:nbn:se:ri:diva-72784 (URN)10.1021/acs.langmuir.3c03709 (DOI)2-s2.0-85186451464 (Scopus ID)
Note

Paxton Juuti and Janne Haapanen (Tampere University, Tampere, Finland) are acknowledged for preparing the LFS coatings and Oskar Karlsson (Swerim, Stockholm, Sweden) for cross-sectional SEM imaging. M.E. thanks SSF, the Swedish Foundation for Strategic Research (grant no. FID15-0029) and Omya International AG for funding. H.T. acknowledges the Alexander von Humboldt Foundation for financial support. D.V. would like to acknowledge financial support via the Priority Programme 2171. A.S. is a researcher in Pro2BE at Karlstad University, a research environment for processes and products for a circular forest-based bioeconomy. 

Available from: 2024-05-16 Created: 2024-05-16 Last updated: 2024-05-16Bibliographically approved
Wojas, N., Tyrode, E., Corkery, R., Ernstsson, M., Wallqvist, V., Järn, M., . . . Claesson, P. M. (2023). Calcite Surfaces Modified with Carboxylic Acids (C2 to C18): Layer Organization, Wettability, Stability, and Molecular Structural Properties. Langmuir, 39(42), 14840-14852
Open this publication in new window or tab >>Calcite Surfaces Modified with Carboxylic Acids (C2 to C18): Layer Organization, Wettability, Stability, and Molecular Structural Properties
Show others...
2023 (English)In: Langmuir, ISSN 0743-7463, E-ISSN 1520-5827, Vol. 39, no 42, p. 14840-14852Article in journal (Refereed) Published
Abstract [en]

A fundamental understanding of the interactions between mineral surfaces and amphiphilic surface modification agents is needed for better control over the production and uses of mineral fillers. Here, we controlled the carboxylic acid layer formation conditions on calcite surfaces with high precision via vapor deposition. The properties of the resulting carboxylic acid layers were analyzed using surface-sensitive techniques, such as atomic force microscopy (AFM), contact angle measurements, angle resolved X-ray photoelectron spectroscopy (XPS), and vibrational sum-frequency spectroscopy. A low wettability was achieved with long hydrocarbon chain carboxylic acids such as stearic acid. The stearic acid layer formed by vapor deposition is initially patchy, but with increasing vapor exposure time, the patches grow and condense into a homogeneous layer with a thickness close to that expected for a monolayer as evaluated by AFM and XPS. The build-up process of the layer occurs more rapidly at higher temperatures due to the higher vapor pressure. The stability of the deposited fatty acid layer in the presence of a water droplet increases with the chain length and packing density in the adsorbed layer. Vibrational sum frequency spectroscopy data demonstrate that the stearic acid monolayers on calcite have their alkyl chains in an all-trans conformation and are anisotropically distributed on the plane of the surface, forming epitaxial monolayers. Vibrational spectra also show that the stearic acid molecules interact with the calcite surface through the carboxylic acid headgroup in both its protonated and deprotonated forms. The results presented provide new molecular insights into the properties of adsorbed carboxylic acid layers on calcite.

National Category
Mechanical Engineering
Identifiers
urn:nbn:se:ri:diva-67911 (URN)10.1021/acs.langmuir.3c01252 (DOI)2-s2.0-85175357225 (Scopus ID)
Note

This work was funded by Omya International AG. ET acknowledges support from the Swedish Research Council (VR).

Available from: 2023-11-27 Created: 2023-11-27 Last updated: 2024-02-28Bibliographically approved
Eriksson, M., Claesson, P. M., Järn, M., Wallqvist, V., Tuominen, M., Kappl, M., . . . Swerin, A. (2023). Effects of liquid surface tension on gas capillaries and capillary forces at superamphiphobic surfaces. Scientific Reports, 13(1), Article ID 6794.
Open this publication in new window or tab >>Effects of liquid surface tension on gas capillaries and capillary forces at superamphiphobic surfaces
Show others...
2023 (English)In: Scientific Reports, E-ISSN 2045-2322, Vol. 13, no 1, article id 6794Article in journal (Refereed) Published
Abstract [en]

The formation of a bridging gas capillary between superhydrophobic surfaces in water gives rise to strongly attractive interactions ranging up to several micrometers on separation. However, most liquids used in materials research are oil-based or contain surfactants. Superamphiphobic surfaces repel both water and low-surface-tension liquids. To control the interactions between a superamphiphobic surface and a particle, it needs to be resolved whether and how gas capillaries form in non-polar and low-surface-tension liquids. Such insight will aid advanced functional materials development. Here, we combine laser scanning confocal imaging and colloidal probe atomic force microscopy to elucidate the interaction between a superamphiphobic surface and a hydrophobic microparticle in three liquids with different surface tensions: water (73 mN m−1), ethylene glycol (48 mN m−1) and hexadecane (27 mN m−1). We show that bridging gas capillaries are formed in all three liquids. Force-distance curves between the superamphiphobic surface and the particle reveal strong attractive interactions, where the range and magnitude decrease with liquid surface tension. Comparison of free energy calculations based on the capillary menisci shapes and the force measurements suggest that under our dynamic measurements the gas pressure in the capillary is slightly below ambient. © 2023, The Author(s).

Place, publisher, year, edition, pages
Nature Research, 2023
National Category
Physical Chemistry
Identifiers
urn:nbn:se:ri:diva-64423 (URN)10.1038/s41598-023-33875-9 (DOI)2-s2.0-85153917455 (Scopus ID)
Note

M.E. thanks SSF, the Swedish Foundation for Strategic Research (Grant No. FID15-0029) and Omya International AG for funding. H.T. acknowledges the Alexander von Humboldt Foundation for financial support. D.V. likes to acknowledge financial support via the Priority Programme 2171. A.S. is researcher at Pro2BE at Karlstad University, a research environment for Processes and products for a circular forest-based bioeconomy. M.E. thanks SSF, the Swedish Foundation for Strategic Research (Grant No. FID15-0029) and Omya International AG for funding. H.T. acknowledges the Alexander von Humboldt Foundation for financial support. D.V. likes to acknowledge financial support via the Priority Programme 2171. A.S. is researcher at Pro2BE at Karlstad University, a research environment for Processes and products for a circular forest-based bioeconomy.

Available from: 2023-05-12 Created: 2023-05-12 Last updated: 2023-12-20Bibliographically approved
Yin, H., Ringman, R., Sedighi Moghaddam, M., Tuominen, M., Dėdinaitė, A., Wålinder, M., . . . Bardage, S. (2023). Susceptibility of surface-modified superhydrophobic wood and acetylated wood to mold and blue stain fungi. Progress in organic coatings, 182, Article ID 107628.
Open this publication in new window or tab >>Susceptibility of surface-modified superhydrophobic wood and acetylated wood to mold and blue stain fungi
Show others...
2023 (English)In: Progress in organic coatings, ISSN 0300-9440, E-ISSN 1873-331X, Vol. 182, article id 107628Article in journal (Refereed) Published
Abstract [en]

The susceptibility of surface-modified wood, surface-modified acetylated wood and acetylated wood to mold and blue stain fungi was investigated. The surface modifications were based on fluorinated and non-fluorinated silicone nanofilaments for increased hydrophobicity. Results showed an increased mold resistance of the surface-modified superhydrophobic wood with mold appearing later or with less intensity on the modified surfaces than on the untreated wood in accelerated mold chamber tests due to the increased water resistance of the samples. All acetylated wood samples exhibited good mold resistance as the available water in acetylated wood was reduced. The surface modifications on acetylated wood had a slightly negative effect on mold resistance due to side effects from the modification. The surface-modified wood showed high blue stain fungi coverage, whereas almost no blue stain fungi were observed on the acetylated wood and surface-modified acetylated wood. The surface-modified superhydrophobic wood showed high mold coverage after conditioning in a high-humidity environment or after exposure to UV irradiation. Meanwhile, the acetylated wood and surface-modified superhydrophobic acetylated wood showed a small amount of mold coverage in these conditions. © 2023 The Authors

Place, publisher, year, edition, pages
Elsevier B.V., 2023
Keywords
Acetylated wood, Blue stain, Mold, Silicone nanofilaments, Superhydrophobic surface modifications, Fungi, Hydrophobicity, Irradiation, Molds, Nanostructures, Surface properties, Wood, Nanofilaments, Silicone nanofilament, Stain fungi, Super-hydrophobic surfaces, Superhydrophobic, Superhydrophobic surface modification, Surface-modification, Surface-modified, Silicones
National Category
Wood Science
Identifiers
urn:nbn:se:ri:diva-64384 (URN)10.1016/j.porgcoat.2023.107628 (DOI)2-s2.0-85153096634 (Scopus ID)
Note

Correspondence Address: Bardage, S.; RISE Research Institutes of Sweden, Sweden; email: stig.bardage@ri.se; Funding details: 2016-01362; Funding details: 2017-02712; Funding details: Karlstads universitet, KAU; Funding text 1: This work was supported by the Formas research council [grant no. 2016-01362 ] and the Vinnova project [grant no. 2017-02712 ]. AS is a researcher at Pro2BE at Karlstad University, the research environment for Processes and Products for a circular Biobased Economy.; Funding text 2: This work was supported by the Formas research council [grant no. 2016-01362] and the Vinnova project [grant no. 2017-02712]. AS is a researcher at Pro2BE at Karlstad University, the research environment for Processes and Products for a circular Biobased Economy.

Available from: 2023-05-05 Created: 2023-05-05 Last updated: 2023-06-08Bibliographically approved
Yin, H., Sedighi Moghaddam, M., Tuominen, M., Dėdinaitė, A., Wålinder, M. & Swerin, A. (2022). Wettability performance and physicochemical properties of UV exposed superhydrophobized birch wood. Applied Surface Science, 584, Article ID 152528.
Open this publication in new window or tab >>Wettability performance and physicochemical properties of UV exposed superhydrophobized birch wood
Show others...
2022 (English)In: Applied Surface Science, ISSN 0169-4332, E-ISSN 1873-5584, Vol. 584, article id 152528Article in journal (Refereed) Published
Abstract [en]

The effect of prolonged ultraviolet (UV) irradiation on the performance of superhydrophobized birch and acetylated birch wood was investigated. The surface modification of the wood was based on a newly developed method using silicone nanofilaments. The combination of surface modification and acetylation of wood showed good wetting resistance also after 600 h of UV exposure, with water contact angles greater than 140° and water uptake 30 times lower by weight than that of the non-surface-modified wood as determined by multicycle Wilhelmy plate measurements. Scanning electron microscopy images revealed that the silicone nanofilaments can still be observed on the wood samples after UV irradiation. The surface-modified wood samples exhibited significant color change after UV exposure. FTIR spectra showed that lignin was degraded on both the non-surface-modified wood surfaces and the wood surface-modified with the silicone nanofilaments. © 2022 The Authors

Place, publisher, year, edition, pages
Elsevier B.V., 2022
Keywords
Acetylated wood, Lignin degradation, Superhydrophobicity, Surface modification, UV irradiation, Wettability, Acetylation, Hydrophobicity, Irradiation, Lignin, Physicochemical properties, Scanning electron microscopy, Silicones, Surface treatment, Wetting, Wood products, Birch wood, Modified wood, Nanofilaments, Surface-modification, Surface-modified, Ultraviolet exposure, Ultraviolet irradiations, Wood samples, Fourier transform infrared spectroscopy, Polysilicones, Radiation Effects, Water Repellence
National Category
Wood Science
Identifiers
urn:nbn:se:ri:diva-58496 (URN)10.1016/j.apsusc.2022.152528 (DOI)2-s2.0-85123687684 (Scopus ID)
Note

 Funding details: 2016-01362; Funding details: 2017-02712; Funding details: Karlstads universitet, KAU; Funding text 1: This work was supported by the Formas research council [grant no. 2016-01362] and the Vinnova project [grant no. 2017-02712]. AS is a researcher at Pro2BE at Karlstad University, the research environment for Processes and Products for a circular Biobased Economy.; Funding text 2: This work was supported by the Formas research council [grant no. 2016-01362] and the Vinnova project [grant no. 2017-02712]. AS is a researcher at Pro2BE at Karlstad University, the research environment for Processes and Products for a circular Biobased Economy.

Available from: 2022-02-18 Created: 2022-02-18 Last updated: 2023-05-17Bibliographically approved
Wojas, N., Dobryden, I., Wallqvist, V., Swerin, A., Järn, M., Schoelkopf, J., . . . Claesson, P. M. (2021). Nanoscale Wear and Mechanical Properties of Calcite: Effects of Stearic Acid Modification and Water Vapor. Langmuir, 37(32), 9826-9837
Open this publication in new window or tab >>Nanoscale Wear and Mechanical Properties of Calcite: Effects of Stearic Acid Modification and Water Vapor
Show others...
2021 (English)In: Langmuir, ISSN 0743-7463, E-ISSN 1520-5827, Vol. 37, no 32, p. 9826-9837Article in journal (Refereed) Published
Abstract [en]

Understanding the wear of mineral fillers is crucial for controlling industrial processes, and in the present work, we examine the wear resistance and nanomech. properties of bare calcite and stearic acid-modified calcite surfaces under dry and humid conditions at the nanoscale. Measurements under different loads allow us to probe the situation in the absence and presence of abrasive wear. The sliding motion is in general characterized by irregular stick-slip events that at higher loads lead to abrasion of the brittle calcite surface. Bare calcite is hydrophilic, and under humid conditions, a thin water layer is present on the surface. This water layer does not affect the friction force. However, it slightly decreases the wear depth and strongly influences the distribution of wear particles. In contrast, stearic acid-modified surfaces are hydrophobic. Nevertheless, humidity affects the wear characteristics by decreasing the binding strength of stearic acid at higher humidity. A complete monolayer coverage of calcite by stearic acid results in a significant reduction in wear but only a moderate reduction in friction forces at low humidity and no reduction at 75% relative humidity (RH). Thus, our data suggest that the wear reduction does not result from a lowering of the friction force but rather from an increased ductility of the surface region as offered by the stearic acid layer. An incomplete monolayer of stearic acid on the calcite surface provides no reduction in wear regardless of the RH investigated. Clearly, the wear properties of modified calcite surfaces depend crucially on the packing d. of the surface modifier and also on the air humidity.

Place, publisher, year, edition, pages
American Chemical Society, 2021
National Category
Tribology (Interacting Surfaces including Friction, Lubrication and Wear)
Identifiers
urn:nbn:se:ri:diva-56145 (URN)10.1021/acs.langmuir.1c01390 (DOI)
Available from: 2021-09-01 Created: 2021-09-01 Last updated: 2023-06-08Bibliographically approved
Yin, H., Sedighi Moghaddam, M., Tuominen, M., Dėdinaitė, A., Wålinder, M. & Swerin, A. (2021). Non-fluorine surface modification of acetylated birch for improved water repellence. Holzforschung, 75(9), 857
Open this publication in new window or tab >>Non-fluorine surface modification of acetylated birch for improved water repellence
Show others...
2021 (English)In: Holzforschung, ISSN 0018-3830, E-ISSN 1437-434X, Vol. 75, no 9, p. 857-Article in journal (Refereed) Published
Abstract [en]

In this work, a non-fluorinated surface treatment, i.e., hydrophobized silicone nanofilaments, was applied on both birch and acetylated birch wood samples via a gas-phase based reaction. A superhydrophobic behavior was observed on both the surface-modified samples as revealed by the static water contact angles (CAs) greater than 160°, also valid for samples prepared with the shortest reaction time of 1 h. The dynamic wettability behavior of the samples was studied by a multicycle Wilhelmy plate method. The surface-modified acetylated birch exhibited a pronounced enhanced water resistance, resulting in very low water uptake of 3 ± 1 wt% after 100 cycles, which was not only about 29 and 5 times lower than that of the non-surface-modified birch and acetylated birch, respectively, but also three times lower than that of the surface-modified birch. Moreover, the aesthetic appearance of the acetylated wood was maintained as the surface modification only resulted in a small color change. This work shows the potential of preparing super water-repellent wood by non-fluorinated surface modification. 

Place, publisher, year, edition, pages
De Gruyter Open Ltd, 2021
Keywords
Acetylated wood, Multicycle Wilhelmy plate method, Non-fluorine surface modification, Silicone nanofilaments, Superhydrophobic coating, Fluorine, Silicones, Superhydrophobicity, Dynamic wettabilities, Fluorinated surface, Superhydrophobic behavior, Surface-modified, Surface-modified samples, Water repellence, Water repellents, Water-resistances, Surface treatment
National Category
Wood Science
Identifiers
urn:nbn:se:ri:diva-53030 (URN)10.1515/hf-2020-0236 (DOI)2-s2.0-85104404837 (Scopus ID)
Note

 Funding details: 2016-01362; Funding details: VINNOVA, 2017-02712; Funding text 1: Research funding: Formas research council is acknowledged for funding the project “Durable water-, oil- and soil repellent wood for outdoor applications via smart surface modification”, grant no. 2016-01362. The Vinnova project 2017-02712 “Bärande utomhusträ” within the BioInnovation program is also acknowledged for supporting the project.

Available from: 2021-05-25 Created: 2021-05-25 Last updated: 2023-05-17Bibliographically approved
Wojas, N., Swerin, A., Wallqvist, V., Järn, M., Schoelkopf, J., Gane, P. & Claesson, P. M. (2021). Surface-Modified and Unmodified Calcite: Effects of Water and Saturated Aqueous Octanoic Acid Droplets on Stability and Saturated Fatty Acid Layer Organization. Langmuir, 37(48), 14135
Open this publication in new window or tab >>Surface-Modified and Unmodified Calcite: Effects of Water and Saturated Aqueous Octanoic Acid Droplets on Stability and Saturated Fatty Acid Layer Organization
Show others...
2021 (English)In: Langmuir, ISSN 0743-7463, E-ISSN 1520-5827, Vol. 37, no 48, p. 14135-Article in journal (Refereed) Published
Abstract [en]

A profound understanding of the properties of unmodified and saturated fatty acid-modified calcite surfaces is essential for elucidating their resistance and stability in the presence of water droplets. Additional insights can be obtained by also studying the effects of carboxylic acid-saturated aqueous solutions. We elucidate surface wettability, structure, and nanomechanical properties beneath and at the edge of a deposited droplet after its evaporation. When calcite was coated by a highly packed monolayer of stearic acid, a hydrophilic region was found at the three-phase contact line. In atomic force microscopy mapping, this region is characterized by low adhesion and a topographical hillock. The surface that previously was covered by the droplet demonstrated a patchy structure of about 6 nm height, implying stearic acid reorganization into a patchy bilayer-like structure. Our data suggest that during droplet reverse dispensing and droplet evaporation, pinning of the three-phase contact line leads to the transport of dissolved fatty carboxylic acid and possibly calcium bicarbonate Ca(HCO3)2 molecules to the contact line boundary. Compared to the surface of intrinsically hydrophobic materials, such as polystyrene, the changes in contact angle and base diameter during droplet evaporation on stearic acid-modified calcite are strikingly different. This difference is due to stearic acid reorganization on the surface and transport to the water-air interface of the droplet. An effect of the evaporating droplet is also observed on unmodified calcite due to dissolution and recrystallization of the calcite surface in the presence of water. In the case where a water droplet saturated with octanoic acid is used instead of water, the stearic acid-coated calcite remains considerably more stable. Our findings are discussed in terms of the coffee-ring effect. © 2021 The Authors. 

Place, publisher, year, edition, pages
American Chemical Society, 2021
Keywords
Calcite, Contact angle, Drops, Evaporation, Magnetic bubbles, Phase interfaces, Saturated fatty acids, Calcite surface, Droplet evaporation, Effect of water, Octanoic acids, Presence of water, Property, Reorganisation, Surface-modified, Three-phase contact line, Water droplets, Stearic acid
National Category
Tribology (Interacting Surfaces including Friction, Lubrication and Wear)
Identifiers
urn:nbn:se:ri:diva-57359 (URN)10.1021/acs.langmuir.1c02387 (DOI)2-s2.0-85120076956 (Scopus ID)
Note

Funding text 1: This work was funded by the Omya International AG. A.S. is a researcher at Pro2BE at the Karlstad University, the research environment on Processes and Products for a Circular Biobased Economy.

Available from: 2021-12-22 Created: 2021-12-22 Last updated: 2023-06-08Bibliographically approved
Abitbol, T., Ahniyaz, A., Alvarez-Asencio, R., Fall, A. & Swerin, A. (2020). Nanocellulose-Based Hybrid Materials for UV Blocking and Mechanically Robust Barriers. ACS Applied Bio Materials, 3(4), 2245-2254
Open this publication in new window or tab >>Nanocellulose-Based Hybrid Materials for UV Blocking and Mechanically Robust Barriers
Show others...
2020 (English)In: ACS Applied Bio Materials, E-ISSN 2576-6422, Vol. 3, no 4, p. 2245-2254Article in journal (Refereed) Published
Abstract [en]

Nanocellulose (NC)-based hybrid coatings and films containing CeO2 and SiO2 nanoparticles (NPs) to impart UV screening and hardness properties, respectively, were prepared by solvent casting. The NC film-forming component (75 wt % of the overall solids) was composed entirely of cellulose nanocrystals (CNCs) or of CNCs combined with cellulose nanofibrils (CNFs). Zeta potential measurements indicated that the four NP types (CNC, CNF, CeO2, and SiO2) were stably dispersed in water and negatively charged at pH values between 6 and 9. The combination of NPs within this pH range ensured uniform formulations and homogeneous coatings and films, which blocked UV light, the extent of which depended on film thickness and CeO2 NP content, while maintaining good transparency in the visible spectrum (∼80%). The addition of a low amount of CNFs (1%) reduced the film hardness, but this effect was compensated by the addition of SiO2 NPs. Chiral nematic self-assembly was observed in the mixed NC film; however, this ordering was disrupted by the addition of the oxide NPs. The roughness of the hybrid coatings was reduced by the inclusion of oxide NPs into the NC matrix perhaps because the spherical oxide NPs were able to pack into the spaces between cellulose fibrils. We envision these hybrid coatings and films in barrier applications, photovoltaics, cosmetic formulations, such as sunscreens, and for the care and maintenance of wood and glass surfaces, or other surfaces that require a smooth, hard, and transparent finish and protection from UV damage.

Place, publisher, year, edition, pages
American Chemical Society, 2020
Keywords
barrier, ceria, coatings, films, nanocellulose, silica, UV, UV blocking
National Category
Engineering and Technology
Identifiers
urn:nbn:se:ri:diva-45002 (URN)10.1021/acsabm.0c00058 (DOI)2-s2.0-85084737634 (Scopus ID)
Note

Funding details: VINNOVA, 2016-04055; Funding text 1: This research was funded through a Marie Curie research fellowship (Vinnova grant 2016-04055) and the RISE NC hybrid materials competence platform.

Available from: 2020-05-27 Created: 2020-05-27 Last updated: 2023-12-06Bibliographically approved
Koppolu, R., Lahti, J., Abitbol, T., Swerin, A., Kuusipalo, J. & Toivakka, M. (2019). Continuous Processing of Nanocellulose and Polylactic Acid into Multilayer Barrier Coatings. ACS Applied Materials and Interfaces, 11(12), 11920-11927
Open this publication in new window or tab >>Continuous Processing of Nanocellulose and Polylactic Acid into Multilayer Barrier Coatings
Show others...
2019 (English)In: ACS Applied Materials and Interfaces, ISSN 1944-8244, E-ISSN 1944-8252, Vol. 11, no 12, p. 11920-11927Article in journal (Refereed) Published
Abstract [en]

Recent years have seen an increased interest toward utilizing biobased and biodegradable materials for barrier packaging applications. Most of the abovementioned materials usually have certain shortcomings that discourage their adoption as a preferred material of choice. Nanocellulose falls into such a category. It has excellent barrier against grease, mineral oils, and oxygen but poor tolerance against water vapor, which makes it unsuitable to be used at high humidity. In addition, nanocellulose suspensions' high viscosity and yield stress already at low solid content and poor adhesion to substrates create additional challenges for high-speed processing. Polylactic acid (PLA) is another potential candidate that has reasonably high tolerance against water vapor but rather a poor barrier against oxygen. The current work explores the possibility of combining both these materials into thin multilayer coatings onto a paperboard. A custom-built slot-die was used to coat either microfibrillated cellulose or cellulose nanocrystals onto a pigment-coated baseboard in a continuous process. These were subsequently coated with PLA using a pilot-scale extrusion coater. Low-density polyethylene was used as for reference extrusion coating. Cationic starch precoating and corona treatment improved the adhesion at nanocellulose/baseboard and nanocellulose/PLA interfaces, respectively. The water vapor transmission rate for nanocellulose + PLA coatings remained lower than that of the control PLA coating, even at a high relative humidity of 90% (38 °C). The multilayer coating had 98% lower oxygen transmission rate compared to just the PLA-coated baseboard, and the heptane vapor transmission rate reduced by 99% in comparison to the baseboard. The grease barrier for nanocellulose + PLA coatings increased 5-fold compared to nanocellulose alone and 2-fold compared to PLA alone. This approach of processing nanocellulose and PLA into multiple layers utilizing slot-die and extrusion coating in tandem has the potential to produce a barrier packaging paper that is both 100% biobased and biodegradable.

Keywords
barrier coatings, multilayer coatings, nanocellulose, polylactic acid, roll-to-roll process, Adhesion, Cellulose, Coatings, Extrusion, High speed cameras, Humidity control, Multilayers, Oxygen, Packaging materials, Polyesters, Suspensions (fluids), Water vapor, Yield stress, High relative humidities, Microfibrillated cellulose, Multi-layer-coating, Oxygen transmission rates, Poly lactic acid, Water vapor transmission rate
National Category
Natural Sciences
Identifiers
urn:nbn:se:ri:diva-38266 (URN)10.1021/acsami.9b00922 (DOI)2-s2.0-85063139115 (Scopus ID)
Available from: 2019-04-02 Created: 2019-04-02 Last updated: 2021-06-17Bibliographically approved
Organisations
Identifiers
ORCID iD: ORCID iD iconorcid.org/0000-0002-6394-6990

Search in DiVA

Show all publications