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Goetz, L., Naseri, N., Nair, S. S., Karim, Z. & Mathew, A. P. (2018). All cellulose electrospun water purification membranes nanotextured using cellulose nanocrystals. Cellulose (London), 25(5), 3011-3023
Open this publication in new window or tab >>All cellulose electrospun water purification membranes nanotextured using cellulose nanocrystals
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2018 (English)In: Cellulose (London), ISSN 0969-0239, E-ISSN 1572-882X, Vol. 25, no 5, p. 3011-3023Article in journal (Refereed) Published
Abstract [en]

Cellulose acetate (CA) fibers were electrospun on a mesh template to create specific surface and pore structures for membrane applications. The mesh template CA fiber mats were impregnated with cellulose nanocrystals at varying weight percentages. The membranes showed nanotextured surfaces and improved mechanical properties post impregnation. More importantly, the hydrophilicity of the original CA fibers was increased from a hydrophobic contact angle of 102°–0° thereby creating an anti-fouling membrane surface structure. The membranes showed rejection of 20–56% for particles of 0.5–2.0 μm, indicating potential of these membranes in rejecting microorganisms from water. Furthermore, high rejection of dyes (80–99%) by adsorption and potential application as highly functional affinity membranes was demonstrated. These membranes can therefore be utilized as all-cellulose, green, scalable and low cost high flux membranes (> 20,000 LMH) for water cleaning applications in food industry where microorganisms and charged contaminants are to be removed.

Place, publisher, year, edition, pages
Springer, 2018
National Category
Bio Materials
Research subject
Wood and Bionanocomposites
Identifiers
urn:nbn:se:ltu:diva-68002 (URN)10.1007/s10570-018-1751-1 (DOI)000431788000020 ()
Note

Validerad;2018;Nivå 2;2018-05-24 (andbra)

Available from: 2018-03-19 Created: 2018-03-19 Last updated: 2018-09-14Bibliographically approved
Zhu, C., Soldatov, A. & Mathew, A. (2017). Advanced microscopy and spectroscopy reveal the adsorption and clustering of Cu(II) onto TEMPO-oxidized cellulose nanofibers. Nanoscale, 9(22), 7419-7428
Open this publication in new window or tab >>Advanced microscopy and spectroscopy reveal the adsorption and clustering of Cu(II) onto TEMPO-oxidized cellulose nanofibers
2017 (English)In: Nanoscale, ISSN 2040-3364, E-ISSN 2040-3372, Vol. 9, no 22, p. 7419-7428Article in journal (Refereed) Published
Abstract [en]

TEMPO (2,2,6,6-tetramethylpiperidine-1-oxylradical)-mediated oxidation nanofibers (TOCNF), as a biocompatible and bioactive material, have opened up a new application of nanocellulose for the removal of water contaminants. This development demands extremely sensitive and accurate methods to understand the surface interactions between water pollutants and TOCNF. In this report, we investigated the adsorption of metal ions on TOCNF surfaces using experimental techniques atthe nano and molecular scales with Cu(II) as the target pollutant in both aqueous and dry forms. Imaging with in situ atomic force microscopy (AFM), together with a study of the physiochemical properties of TOCNF caused by adsorption with Cu(II) in liquid, were conducted using the PeakForce Quantitative NanoMechanics (PF-QNM) mode at the nano scale. The average adhesion force between the tip and the target single TOCNF almost tripled after adsorption with Cu(II) from 50 pN to 140 pN. The stiffness of the TOCNF was also enhanced because the Cu(II) bound to the carboxylate groups and hardened the fiber. AFM topography, scanning electron microscopy-energy dispersive X-ray spectroscopy (SEM-EDS) mapping and X-ray photoelectron spectroscopy (XPS) indicated that the TOCNF were covered by copper nanolayers and/or nanoparticles after adsorption. The changes in the molecular structure caused by the adsorption were demonstrated by Raman and attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR). This methodology will be of great assistance to gain qualitative and quantitative information on the adsorption process and interaction between charged entities in aqueous medium.

Place, publisher, year, edition, pages
Royal Society of Chemistry, 2017
National Category
Other Physics Topics Bio Materials
Research subject
Experimental Physics; Wood and Bionanocomposites
Identifiers
urn:nbn:se:ltu:diva-63514 (URN)10.1039/c7nr01566f (DOI)000402881600009 ()28530277 (PubMedID)2-s2.0-85021169078 (Scopus ID)
Note

Validerad;2017;Nivå 2;2017-06-14 (rokbeg)

Available from: 2017-05-24 Created: 2017-05-24 Last updated: 2018-07-10Bibliographically approved
Herrera, M. A., Mathew, A. P. & Oksman, K. (2017). Barrier and mechanical properties of plasticized and cross-linked nanocellulose coatings for paper packaging applications. Cellulose (London), 24(9), 3969-3980
Open this publication in new window or tab >>Barrier and mechanical properties of plasticized and cross-linked nanocellulose coatings for paper packaging applications
2017 (English)In: Cellulose (London), ISSN 0969-0239, E-ISSN 1572-882X, Vol. 24, no 9, p. 3969-3980Article in journal (Refereed) Published
Abstract [en]

Barrier, mechanical and thermal properties of porous paper substrates dip-coated with nanocellulose (NC) were studied. Sorbitol plasticizer was used to improve the toughness, and citric acid cross-linker to improve the moisture stability of the coatings. In general, the addition of sorbitol increased the barrier properties, maximum strength and toughness as well as the thermal stability of the samples when compared to the non-modified NC coatings. The barrier properties significantly improved, especially for plasticized NC coating’s, where the oxygen permeability value was as low as 0.7 mL μm day−1 m−2 kPa−1 at 49% RH and the water vapor permeability was reduced by 60%. Furthermore, we found that the cross-linked plasticized NC coating had a smoother surface (50% lower roughness) compared to non-modified ones. This study shows that the environmentally friendly additives sorbitol and citric acid had positive effects on NC coating properties, increasing its potential use in paper-based packaging applications.

Place, publisher, year, edition, pages
Springer, 2017
National Category
Bio Materials
Research subject
Wood and Bionanocomposites
Identifiers
urn:nbn:se:ltu:diva-65061 (URN)10.1007/s10570-017-1405-8 (DOI)000407437000026 ()2-s2.0-85023188224 (Scopus ID)
Note

Validerad;2017;Nivå 2;2017-08-17 (rokbeg)

Available from: 2017-08-14 Created: 2017-08-14 Last updated: 2018-07-10Bibliographically approved
Jalvo, B., Mathew, A. P. & Rosal, R. (2017). Coaxial poly(lactic acid) electrospun composite membranes incorporating cellulose and chitin nanocrystals. Journal of Membrane Science, 544, 261-271
Open this publication in new window or tab >>Coaxial poly(lactic acid) electrospun composite membranes incorporating cellulose and chitin nanocrystals
2017 (English)In: Journal of Membrane Science, ISSN 0376-7388, E-ISSN 1873-3123, Vol. 544, p. 261-271Article in journal (Refereed) [Artistic work] Published
Abstract [en]

In this study, we used electrospinning to produce core-shell nanofibers of poly(lactic acid) as core and polyacrylonitrile/cellulose nanocrystals (CNC) or polyacrylonitrile/chitin nanocrystals (ChNC) as shell. Electrospun materials prepared at different nanocrystal concentrations were tested and assayed as microfiltration membranes. The coaxial membranes presented a maximum pore size in the 1.2–2.6 μm range and rejections > 85% for bacterial cells (0.5 × 2.0 μm) and > 99% for fungal spores (> 2 μm). The morphological and mechanical properties and the water permeability of the nanocomposite membranes were studied. The morphological characterization showed random fibers of beadless and well-defined core/shell structured fibers with diameter generally below the micron size with presence of secondary ultrafine nanofibers. Tensile strength and Young's modulus of elasticity improved with respect to coaxial membranes without nanocrystals with best mechanical properties achieved at 5 wt% CNC and 15 wt% ChNC loadings. The enhancement was attributed to the reinforcing effect of the percolating network of cellulose nanocrystals. Water permeability increased for all membranes loaded with nanocrystals with respect to the coaxial fibers without nanocrystals, the highest corresponding to ChNC composites with up to a 240% increase over non-loaded membranes. Composite membranes prepared with CNC in their shell were hydrophilic, in contrast with the hydrophobic PLA core, while coaxial fibers with ChNC were superhydrophilic. CNC membranes were negatively charged but ChNC originated neutral or positively charged membranes due to the contribution of deacetylated chitin structural units. Upon exposure to E. coli cultures, composite membranes containing ChNC showed a high antimicrobial action and were essentially free of bacterial colonization under strong biofilm formation conditions.

Place, publisher, year, edition, pages
Elsevier, 2017
National Category
Bio Materials
Research subject
Wood and Bionanocomposites
Identifiers
urn:nbn:se:ltu:diva-65624 (URN)10.1016/j.memsci.2017.09.033 (DOI)
Note

Validerad;2017;Nivå 2;2017-09-19 (andbra)

Available from: 2017-09-13 Created: 2017-09-13 Last updated: 2017-11-24Bibliographically approved
Hooshmand, S., Aitomäki, Y., Berglund, L., Mathew, A. P. & Oksman, K. (2017). Enhanced alignment and mechanical properties through the use of hydroxyethyl cellulose in solvent-free native cellulose spun filaments. Composites Science And Technology, 150, 79-86
Open this publication in new window or tab >>Enhanced alignment and mechanical properties through the use of hydroxyethyl cellulose in solvent-free native cellulose spun filaments
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2017 (English)In: Composites Science And Technology, ISSN 0266-3538, E-ISSN 1879-1050, Vol. 150, p. 79-86Article in journal (Refereed) Published
Abstract [en]

In this study, the addition of hydroxyethyl cellulose (HEC) in cellulose nanofiber filaments is shown to improve the solvent-free processing and mechanical properties of these biobased fibers as well as their compatibility with epoxy. An aqueous dope of cellulose nanofiber (CNF) with HEC was spun and the resulting filaments cold-drawn. The HEC increased the wet strength of the dope allowing stable spinning of low concentrations of CNF. These lower concentrations promote nanofiber alignment which is further improved by cold-drawing. Alignment improves the modulus and strength and an increase of over 70% compared to the as-spun CNF only filaments was achieved. HEC also decreases hydrophilicity thus increasing slightly the interfacial shear strength of the filaments with epoxy resin. The result is continuous biobased fibers with improved epoxy compatibility that can be prepared in an upscalable and environmentally friendly way. Further optimization is expected to increase draw ratio and consequently mechanical properties.

Place, publisher, year, edition, pages
Elsevier, 2017
National Category
Bio Materials
Research subject
Wood and Bionanocomposites
Identifiers
urn:nbn:se:ltu:diva-65051 (URN)10.1016/j.compscitech.2017.07.011 (DOI)000412041300008 ()2-s2.0-85024383663 (Scopus ID)
Note

Validerad; 2017; Nivå 2; 2017-08-14 (andbra)

Available from: 2017-08-14 Created: 2017-08-14 Last updated: 2018-03-05Bibliographically approved
Karim, Z., Hakalahti, M., Tammelin, T. & Mathew, A. P. (2017). In situ TEMPO surface functionalization of nanocellulose membranes for enhanced adsorption of metal ions from aqueous medium. RSC Advances, 7(9), 5232-5241
Open this publication in new window or tab >>In situ TEMPO surface functionalization of nanocellulose membranes for enhanced adsorption of metal ions from aqueous medium
2017 (English)In: RSC Advances, ISSN 2046-2069, E-ISSN 2046-2069, Vol. 7, no 9, p. 5232-5241Article in journal (Refereed) Published
Abstract [en]

The current work demonstrates an innovative approach to develop nanocellulose based membranes with high water permeability, mechanical stability and high functionality via (1) tailoring the composition of the support layer of sludge microfibers/cellulose nanofibers (CNFSL) and (2) in situ TEMPO functionalization of the thin functional layer of cellulose nanocrystals (CNCBE) to enhance the metal ion adsorption capacity. SEM studies showed a porous network structure of the cellulose support layer and a denser functional layer with CNCBE embedded within gelatin matrix. AFM studies indicated the presence of a nanoscaled coating and increased roughness of membranes surface after TEMPO modification whereas FT-IR and conductometric titration confirmed the introduction of carboxyl groups upon TEMPO oxidation. The contact angle measurement results showed improved hydrophilic nature of membranes after in situ TEMPO functionalization. High networking potential of CNFSL made the membrane support layer tighter with a concomitant decrease in the average pore size from 6.5 to 2.0 μm. The coating with CNCBE further decreased the average pore size to 0.78 and 0.58 μm for S/CNCBE and S–CNFSL/CNCBE, respectively. In parallel, a drastic decrease in water flux (8000 to 90 L MPa−1 h−1 m−2) after coating with CNCBE was recorded but interestingly in situ functionalization of top CNCBE layer did not affect water flux significantly. The increase in adsorption capacity of ≈1.3 and ≈1.2 fold was achieved for Cu(II) and Fe(II)/Fe(III), respectively after in situ TEMPO functionalization of membranes. Biodegradation study confirmed the stability of layered membranes in model wastewater and a complete degradation of membranes was recorded after 15 days in soil.

Place, publisher, year, edition, pages
Royal Society of Chemistry, 2017
National Category
Bio Materials
Research subject
Wood and Bionanocomposites
Identifiers
urn:nbn:se:ltu:diva-61628 (URN)10.1039/C6RA25707K (DOI)000393753200042 ()2-s2.0-85010409286 (Scopus ID)
Note

Validerad; 2017; Nivå 2; 2017-02-07 (andbra)

Available from: 2017-01-25 Created: 2017-01-25 Last updated: 2018-11-16Bibliographically approved
Naseri, N., Poirier, J.-M., Girandon, L., Fröhlich, M., Oksman, K. & Mathew, A. P. (2016). 3-Dimensional Porous Nanocomposite Scaffolds Based on Cellulose Nanofibers for Cartilage Tissue Engineering (ed.). Paper presented at . RSC Advances, 6(8), 5999-6007
Open this publication in new window or tab >>3-Dimensional Porous Nanocomposite Scaffolds Based on Cellulose Nanofibers for Cartilage Tissue Engineering
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2016 (English)In: RSC Advances, ISSN 2046-2069, E-ISSN 2046-2069, Vol. 6, no 8, p. 5999-6007Article in journal (Refereed) Published
Abstract [en]

Fully bio-based three-dimensional porous scaffold for cartilage repair was prepared via freeze-drying where cellulose nanofibers, which were cytocompatible, were used as mechanical reinforcement (70-90 wt%) in a matrix of gelatin and chitosan (9:1) and crosslinked using genipin. Morphology studies showed that the scaffolds had interconnected pores with favorable pore diameters (< 250 μm) for cell growth. Compression modulus of the scaffolds (1-3 MPa) at room conditions was in the range for natural cartilage and decreased significantly (0.03-0.05 MPa) in phosphate buffered saline (PBS) at 37°C. The high PBS uptake shown by the scaffolds (< 3000 wt%) was attributed to liquid trapped in the pores during immersion in PBS. Furthermore, the scaffolds showed good cytocompatibility towards chondrocytes, which attached and proliferated properly. The scaffolds are considered to have potential in cartilage tissue engineering due to high porosity (≈ 95%) and good mechanical performance that promote cell attachment and extracellular matrix (ECM) production.

National Category
Bio Materials
Research subject
Wood and Bionanocomposites
Identifiers
urn:nbn:se:ltu:diva-14773 (URN)10.1039/c5ra27246g (DOI)000368858000002 ()2-s2.0-84955488655 (Scopus ID)e329b88d-c446-43d6-ae32-ad7c516c5318 (Local ID)e329b88d-c446-43d6-ae32-ad7c516c5318 (Archive number)e329b88d-c446-43d6-ae32-ad7c516c5318 (OAI)
Note
Validerad; 2016; Nivå 2; 20140922 (narnas)Available from: 2016-09-29 Created: 2016-09-29 Last updated: 2018-07-10Bibliographically approved
Goetz, L., Karim, Z. & Mathew, A. P. (2016). Effect of micropatterned cellulose acetate membranes impregnated with cellulose and chitin nanocrystals on water filtration membrane behavior (ed.).
Open this publication in new window or tab >>Effect of micropatterned cellulose acetate membranes impregnated with cellulose and chitin nanocrystals on water filtration membrane behavior
2016 (English)Manuscript (preprint) (Other academic)
National Category
Bio Materials
Research subject
Wood and Bionanocomposites
Identifiers
urn:nbn:se:ltu:diva-12827 (URN)bfa1e171-295f-4a4a-8edf-ca98d501f082 (Local ID)bfa1e171-295f-4a4a-8edf-ca98d501f082 (Archive number)bfa1e171-295f-4a4a-8edf-ca98d501f082 (OAI)
Available from: 2016-09-29 Created: 2016-09-29 Last updated: 2017-11-24
Naseri, N., Mathew, A. P. & Oksman, K. (2016). Electrospinnability of bionanocomposites with high nanocrystal loadings: The effect of nanocrystal surface characteristics (ed.). Carbohydrate Polymers, 147, 464-472
Open this publication in new window or tab >>Electrospinnability of bionanocomposites with high nanocrystal loadings: The effect of nanocrystal surface characteristics
2016 (English)In: Carbohydrate Polymers, ISSN 0144-8617, E-ISSN 1879-1344, Vol. 147, p. 464-472Article in journal (Refereed) Published
Abstract [en]

This paper deals with the effect of solution properties and nanoparticle surface chemistry on the spinnability of a chitosan/polyethylene oxide (PEO) with high concentration (50 wt%) of chitin and cellulose nanocrystals and the properties of the resultant nanocomposite fibers/fiber mats. Electrospinning dispersions with cellulose nanocrystals having sulphate surface groups showed poor spinnability compared to chitin nanocrystals with amide and amino groups. Chitin nanocrystal based dispersions showed good spinnability and continuous fiber formation whereas cellulose nanocrystal system showed discontinuous fibers and branching. The viscosity and surface tension are shown to impact this behavior, but conductivity did not. Poor spinnability observed for cellulose nanocrystal based fibers was attributed to the coagulation of negatively charged cellulose nanocrystals and positively charged chitosan. The study showed that the nanocrystal surface charge and interactions with the chitosan/PEO matrix have a significant impact on the spinnability of bionanocomposites.

National Category
Bio Materials
Research subject
Wood and Bionanocomposites
Identifiers
urn:nbn:se:ltu:diva-5058 (URN)10.1016/j.carbpol.2016.04.018 (DOI)27178953 (PubMedID)2-s2.0-84964556478 (Scopus ID)313b97d0-0dbf-41ee-844c-e29802d90d50 (Local ID)313b97d0-0dbf-41ee-844c-e29802d90d50 (Archive number)313b97d0-0dbf-41ee-844c-e29802d90d50 (OAI)
Note

Validerad; 2016; Nivå 2; 20160411 (andbra)

Available from: 2016-09-29 Created: 2016-09-29 Last updated: 2018-07-10Bibliographically approved
Vuddanda, P. R., Mathew, A. P. & Velaga, S. (2016). Electrospun nanofiber Mats for ultrafast release of ondansetron (ed.). Reactive & functional polymers, 99, 65-72
Open this publication in new window or tab >>Electrospun nanofiber Mats for ultrafast release of ondansetron
2016 (English)In: Reactive & functional polymers, ISSN 1381-5148, E-ISSN 1873-166X, Vol. 99, p. 65-72Article in journal (Refereed) Published
Abstract [en]

Nanofiber mats or films are promising platforms that can offer unique opportunities in oromucosoal drug delivery. However, the conventional film forming technologies are unable to produce mats with unique internal microstructure and properties. Thus, the present study was aimed to develop electrospun nanofiber mats of a model drug -ondansetron hydrochloride (OND) for ultrafast drug release. Polyvinyl alcohol (PVA), a water soluble synthetic polymer was used in the preparation of nanofiber mats and casting film. The OND nanofiber mats and conventional films were prepared by electrospinning and casting methods, respectively. Different electrospinning process variables (feed rate, electric voltage and tip to collector distance) were investigated. Nanofiber mats and casted films were characterized using Scanning electron microscopy (SEM), Atomic force microscopy (AFM), Differential scanning calorimetry (DSC), Powder X-ray diffraction (PXRD), and Attenuated total reflection – Fourier transform infrared spectroscopy (ATR-FTIR). The folding endurance, drug content, wetting behaviour and disintegration properties and in-vitro drug release studies were also performed.The SEM and AFM had revealed that the nanofiber mats were formed with smooth uniform texture. Solid state studies indicated that the OND was in amorphous state and uniformly dispersed in PVA mats and a film. The electrospun nanofiber mat and casted film of OND showed sufficient mechanical properties. Wet sponge method suggested that OND nanofiber mats were simultaneously wetted and disintegrated within 10 s, which is ultrafast compared to casted films. The total amount of OND was released in 90 s (1.5 min) and 1800 s (30 min) from OND-PVA electrospun nanofiber mats and casted film, respectively. OND nanofiber mats can be promising alternatives to existing solid dosage forms for ultrafast release of drugs.

National Category
Other Health Sciences Bio Materials
Research subject
Health Science; Wood and Bionanocomposites
Identifiers
urn:nbn:se:ltu:diva-3577 (URN)10.1016/j.reactfunctpolym.2015.12.009 (DOI)000370884800010 ()2-s2.0-84952333009 (Scopus ID)166f6320-be38-44c2-8610-1266f4c5fd13 (Local ID)166f6320-be38-44c2-8610-1266f4c5fd13 (Archive number)166f6320-be38-44c2-8610-1266f4c5fd13 (OAI)
Note

Validerad; 2016; Nivå 2; 20151221 (andbra)

Available from: 2016-09-29 Created: 2016-09-29 Last updated: 2018-07-10Bibliographically approved
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