Forskning

• Material för miljön
• Helt biobaserade membran/filter för vattenrening
• Ytkemi och interaktioner, mekaniska egenskaper, viskoelastiska egenskaper, in situ SAXS
• Atomkraftsmikroskopi (förstå egenskaper i nanoskala, kolloidal sond)

Material för hälsa

• Biobaserat material för medicinska tillämpningar
• Vävnadsteknik, sårförband, antifouling och antibakteriella material

Syntes- och bearbetningsmetoder för hållbara material

• Nanocellulosa och nanochitin isolering och karakterisering
• Design av återvinning och cirkularitet av material
• Bearbetning och karakterisering av bionanokompositer, hybrider och tvärbundna polymerer

Pågående projekt

Katalytisk fraktionering av skogsrester och återvunna textilier för att generera material och kemikalier)

Mistra Safechem, 2020-2024

Forskningsprogrammet Safe and Efficient Chemistry by Design (SafeChem) syftar till att förbättra industrins förmåga att minska farlig kemikalieexponering för människor och miljön genom implementering av det verktyg som utvecklats inom programmet.

Cirkularitet av material och förlängning av värdekedjan för producerade varor är ett område av yttersta relevans i gröna och hållbara industrier och samhällen. Den här uppgiften kommer att fokusera på återvinning och omvandling av bomullsbaserade textilier samt fraktionering och omvandling av lågvärderade lignocellulosaråvaror som toppar, rötter och grenar från skogsbruket till kemikalier, nanocellulosa och förnybara produkter framställda av dessa material.

Projektet sker i samarbete med textil-, skogs- samt biobränsle- och kemisk industri.

3D-utskrift av biobaserade filter funktionaliserade med nanocellulosa för vattenrening

Wallenberg Wood Science Center Finansiering, Functional Materials Research vid Stockholms universitet, 2019-2022 (www.wwsc.se)

Det övergripande projektet syftar till att utveckla nya vägar för att bearbeta och producera filter genom 3D-utskrivet material. Den aktiva delen i filtren kommer att baseras på nanokompositer med nanocellulosa som komponenter, för att belysa hur porositeten och ytkemin kan skräddarsys för att ge högt vattenflöde, hög separationseffektivitet och långtidsstabilitet i våt miljö.

Förstå nanocellulosahybridmembran med hjälp av avancerad atomkraftsmikroskopi (AFM), Raman/NMR-spektroskopi, röntgenspridning och beräkningskemi

Vetenskapsrådet (2018-2021)

Projektet utvecklar experimentella procedurer för att undersöka biobaserade hybrider i flytande medium/våta förhållanden med hjälp av atomkraftsmikroskopi och spektroskopi och in situ röntgenspridning, kombinerat med beräkningskemi, är tänkt i projektet för att utvärdera och förutsäga självmontering mellan nanocellulosa och andra nanopartiklar och förstå hur de självmonterade morfologierna driver porstrukturbildningen och adsorptionen i biobaserade membran och filter som används för vattenrening.

Mistra, Smarta material, TERRACLEAN 2017-2024
www.mistraterraclean.com

Oavsett källan måste reningstekniken förbättras. Inte minst eftersom dagens lösningar som ofta bygger på olika typer av filter och membran inte kan fånga in alla typer av föroreningar, framförallt inte ämnen som förekommer i små mängder. Här bidrar vi med lösningar för att utveckla smarta material ör att utveckla smarta material för borttagning av kemiska ämnen, avfall och föroreningar från omgivande vatten och luft i miljön och industriavlopp.

Tidigare finansiering

Projektkoordinator: FP7-NMP-2011-SMALL-5, förslagets referensnummer: 280519-2 2011, budget: 4 miljoner euro, samordnare, 2012-2016

Principal Investigator:

• Wallenberg Wood Science Center Finansiering, Funktionell materialforskning vid Stockholms universitet, 2015-2019
• Stockholms universitets fakultetsstöd, 2015-2019
• VR 2013, 2014-2017.; Svenska forskningslänkar
• Internationella forskningsanslag, Sydafrika, 2009-2011
• Svenska forskningslänkar, Internationella forskningsanslag, Indien 2009-2011
• Nanomembran för rening av gaser och vätskor, Innovationsbron, (2009)
• Biobaserade byggnadsställningar, membran och hydrogeler för förbättrad sårläkning och benregenerering (Bioheal) 
• Svenska forskningslänkar, Internationellt samarbete: 2017-2020

Partner: CEREAL (ERANET-SUSFOOD, 2014–2017; n-POSSCOG, nr: 2011-02071 MNT-ERA.NET

Transnationell utlysning 2011; H2020, NanoTextsurf, 2017-2020. www.nanotextsurf.eu

I urval från Stockholms universitets publikationsdatabas

• In-Situ Growth of Metal Oxide Nanoparticles on Cellulose Nanofibrils for Dye Removal and Antimicrobial Applications

  2020. Luis Valencia (et al.). ACS Applied Nano Materials 3 (7), 7172-7181

  Artikel

  Nanocellulose is known to act as a platform for the in-situ formation of metal oxide nanoparticles, where the multiple components of the resultant hybrids act synergistically toward specific applications. However, typical mineralization reactions require hydrothermal conditions or addition of further reducing agents. Herein, we demonstrate that carboxylated cellulose nanofibril-based films can spontaneously grow functional metal oxide nanoparticles during the adsorption of heavy metal ions from water, without the need of any further chemicals or temperature. Despite the apparent universality of this behavior with different metal ions, this work focuses on studying the in-situ formation of copper oxide nanoparticles on TOCNF films as well as the resultant hybrid films with improved functionality toward dye removal from water and antimicrobial activity. Using a combination of cutting-edge techniques (e.g., in-situ SAXS and QCMD) to systematically follow the nanoparticle formation on the nanocellulosic films in real time, we suggest a plausible mechanism of assembly. Our results confirm that carboxylated cellulose nanofibril films act as universal substrate for the formation of metal oxide nanoparticles, and thus hybrid nanomaterials, during metal ion adsorption processes. This phenomenon enables the upcycling of nanocellulosic materials through multistage applications, thus increasing its sustainability and efficiency in terms of an optimal use of resources.

  Läs mer om In-Situ Growth of Metal Oxide Nanoparticles on Cellulose Nanofibrils for Dye Removal and Antimicrobial Applications

• CelloMOF

  2019. Sahar Sultan (et al.). Advanced Functional Materials 29 (2)

  Artikel

  3D printing is recognized as a powerful tool to develop complex geometries for a variety of materials including nanocellulose. Herein, a one-pot synthesis of 3D printable hydrogel ink containing zeolitic imidazolate frameworks (ZIF-8) anchored on anionic 2,2,6,6-tetramethylpiperidine-1-oxylradical-mediated oxidized cellulose nanofibers (TOCNF) is presented. The synthesis approach of ZIF-8@TOCNF (CelloZIF8) hybrid inks is simple, fast (approximate to 30 min), environmentally friendly, takes place at room temperature, and allows easy encapsulation of guest molecules such as curcumin. Shear thinning properties of the hybrid hydrogel inks facilitate the 3D printing of porous scaffolds with excellent shape fidelity. The scaffolds show pH controlled curcumin release. The synthesis route offers a general approach for metal-organic frameworks (MOF) processing and is successfully applied to other types of MOFs such as MIL-100 (Fe) and other guest molecules as methylene blue. This study may open new venues for MOFs processing and its large-scale applications.

  Läs mer om CelloMOF

• Mechanically robust high flux graphene oxide - nanocellulose membranes for dye removal from water

  2019. Peng Liu, Chuantao Zhu, Aji P. Mathew. Journal of Hazardous Materials 371, 484-493

  Artikel

  Ultrathin graphene oxide (GO) layer was fabricated on cellulose nanofiber (CNF) membrane to achieve robust crosslinker free layered membrane with synergistic water flux and separation performance. Unlike pristine cellulosic or GO membranes, GO-CNF hybrid membranes exhibited significantly improved mechanical stability in both dry and wet states. All membranes showed negative surface zeta potential. GO: CNF membrane (1:100) exhibited significantly high water flux (18,123 +/- 574 Lm(-2) h(-1) bar(-1)); higher than that of CNF membrane or the hydrophilic commercial reference membrane with comparable pore structure (Nylon 66, 0.2 mu m). We hypothyse that a unique surface structure of standing inserted GO nanosheets observed at low concentrations of GO contributes enormously to its ultrafast water permeability through creation of numerous water transport nanochannels. The aniosptropic layered membranes exhibited > 90% rejection of positively and negatively charged dyes through a combination of electrostatic interaction, hydrophobic interactions and molecular size exclusion. Construction of an ultrathin GO layer on CNF offers a unique and efficient way to prepare highly functional, economical and scalable water purification membranes having significant advantage with respect to flux, mechanical stability and rejection of dyes compared to isotropic membrane with GO nanosheets randomly dispersed in the cellulose nanofibrous network.

  Läs mer om Mechanically robust high flux graphene oxide - nanocellulose membranes for dye removal from water

• Waterborne nanocellulose coatings for improving the antifouling and antibacterial properties of polyethersulfone membranes

  2020. Andrea Aguilar-Sanchez (et al.). Journal of Membrane Science

  Artikel

  This article presents a waterborne nanocellulose coating process to change the surface characteristics and mitigate fouling of commercially available polyethersulfone (PES) microfiltration membranes. An extensive comparative study between nanoporous and nano-textured layers composed of cellulose nanocrystals (CNC) or TEMPO-oxidized cellulose nanofibrils (T-CNF), which were coated on the PES membrane by taking advantage of the electrostatic interactions between the PES substrate, a polyallylamine hydrochloride (PAHCl) anchoring layer, and the nanocellulose functional layer. Coated PES membranes exhibited decreased surface roughness and pore sizes as well as rejection of compounds with a M_w above 150 kDa, while the water permeability and mechanical properties of remained largely unaffected. The coatings improved the wettability as confirmed by a reduction of the contact angle by up to 52% and exhibited a higher negative surface charge compared to the uncoated membranes over a pH range of 4–8. A significant reduction in organic fouling was observed for the coated membranes demonstrated by bovine serum albumin (BSA) adsorption studies on T-CNF and CNC surfaces using Quartz Crystal Microbalance with Dissipation monitoring (QCM-D), UV–vis spectroscopy and FTIR mapping after exposing the membranes to dynamic adsorption of BSA. The T-CNF coating exhibited effective antibacterial action against Escherichia coli (E. coli) attributed to the pH reduction effect induced by the carboxyl groups; while CNC coatings did not show this property. This work demonstrates a simple, green, and easy-to-scale layer-by-layer coating process to tune the membrane rejection and to improve antifouling and antibacterial properties of commercially available membranes.

  Läs mer om Waterborne nanocellulose coatings for improving the antifouling and antibacterial properties of polyethersulfone membranes

• All-cellulose functional membranes for water treatment

  2021. Dimitrios Georgouvelas (et al.). Carbohydrate Polymers 264

  Artikel

  In this study, we present a facile, one-step method for the manufacturing of all-cellulose, layered membranes containing cellulose nanocrystals (CNC), TEMPO (2,2,6,6-tetramethylpiperidine-1-oxyl radical)-mediated oxidized cellulose nanofibers (TO-CNF), or zwitterionic polymer grafted cellulose nanocrystals (CNC-g-PCysMA) as functional entities in combination with cellulose fibers and commercial grade microfibrillated cellulose. The presence of active sites such as hydroxyl, carbonyl, thioethers, and amines, gave the membranes high adsorption capacities for the metal ions Au (III), Co (II), and Fe (III), as well as the cationic organic dye methylene blue (MB). Furthermore, the membranes served as excellent metal-free catalysts for the decolorization of dyes via hydrogenation. A 3-fold increase of the hydrogenation efficiency for cationic dyes such as rhodamine B (RhB) and methylene blue was obtained in the presence of membranes compared to NaBH₄ alone. Water-based processing, the abundance of the component materials, and the multifunctional characteristics of the membranes ensure their potential as excellent candidates for water purification systems.

  Läs mer om All-cellulose functional membranes for water treatment

• Converting cellulose nanocrystals into photocatalysts by functionalisation with titanium dioxide nanorods and gold nanocrystals

  2020. Santhosh S. Nair (et al.). RSC Advances 10 (61), 37374-37381

  Artikel

  Cellulose nanocrystals (CNCs) are promising building blocks for water purification due to their high surface area, tuneability of surface charge and grafting of surface groups depending on the pollutants. In this report we have converted CNCs into photocatalysts, without altering the surface groups, byin situgrowth of TiO(2)nanorods (NRs) and functionalization with Au nanocrystals (NCs) for enhanced light absorption. The control of the density of the NRs assures that the CNC surface and functionalities are accessible for the pollutant, followed by the photocatalytic degradation on the light absorption layer under solar illumination. This seed-mediated NR synthesis can be applied to realize a series of CNC-inorganic NR photocatalysts. The low temperature (90 degrees C compared to commonly reported growth at 150 degrees C) of the NR growth provides the opportunity to use nanostructured biopolymers as functional substrates for preparation of photocatalysts using a bio-inspired design.

  Läs mer om Converting cellulose nanocrystals into photocatalysts by functionalisation with titanium dioxide nanorods and gold nanocrystals

Visa alla publikationer av Aji Mathew vid Stockholms universitet