Profiles

Aji Mathew

Aji Mathew

Professor

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Arbetar vid Institutionen för material- och miljökemi
Telefon 08-16 12 56
E-post aji.mathew@mmk.su.se
Besöksadress Svante Arrhenius väg 16 C
Rum C432
Postadress Institutionen för material- och miljökemi 106 91 Stockholm

Om mig

I hold a PhD in Polymer chemistry (2001) from Mahatma Gandhi University, India on the topic of Interpenetrating Polymer Networks based on Naural Rubber and Polystyrene. After PhD  I carried out postdoctoral  research at CERMAV, Universitet Joseph Fourier, Grenoble, France and  Norwegian University of Science and Technology (NTNU),  Trondheim, Norway working  on  the processing and characterisation of nanocellulose  and its nanocomposites. I started my academic career as  Assistant Professor, in 2007   at  Luleå  University of Science and Technology, Luleå, Sweden and was appionted as Associate Professor in 2011 with focus on biobased nanocomposites. I took up the Associate Professor position at the Department of Materials and Environmental  Chemistry, Stockholm University in 2015 and  was promoted to full professor in  Feb 2017 with focus on Biobased functional materials.  My current research have a strong focus on designing materials in the nanoscale  for   a sustainable society.

 

2. Research (10-30 words)

Materials for environment

  • Fully biobased membranes/ filters for water purification
  • Surface chemistry and interactions, mechanical properties, viscoelastic properties, in situ SAXS
  • Atomic force microscopy (understanding properties at nano scale, colloidal probe)

Materials for  health

  • Biobased materials for medical applications
  • Tissue engineering, wound dressing, antifouling and antibacterial materials 

Synthesis and processing  methods for sustainable  materials

  • Nanocellulose and nanochitin isolation and characterization
  • Designing of recycling and circularity of materials 
  • Processing and characterisation of bionanocomposites, hybrids and crosslinked polymers

On-going projects

Catalytic fractionation of forest residues and recycled textiles to generate materials and chemicals ) Mistra Safechem, 2020-2024 

The research programme Safe and Efficient Chemistry by Design (SafeChem) aims to improve the ability of industry to reduce hazardous chemical exposure to the human population and the environment through implementation of the toolbox system developed within the programme. Circularity of materials and extension of the value chain of produced goods is an area of utmost relevance in green and sustainable industries and society. This task will focus on recycling and conversion of cottonbased textiles, and fractionation and conversion of low valued lignocellulosic feedstocks such as tops, roots and branches from forestry into chemicals, nanocellulose and renewable products produced from these materials . The project will interact with, and contribute to, industries along the value chain including e.g. the textile industry, forest industry, and the biofuel and chemical industry.

3D printing of biobased filters functionalised with nanocellulose for water purification Wallenberg Wood Science Centre Funding, Functional Materials Research at Stockholm University, 2019-2022 (www.wwsc.se)

The overall project aims to develop new routes to process and produce filters by melt-based 3D printing. The active part in the filters will be based on nanocomposites having nanocellulose as a component. to elucidate how the  porosity and surface chemistry can be tailored to provide high water flux, high separation efficiency, and long-term stability in wet environment. 

Understanding nanocellulose hybrid membranes by means of advanced atomic force microscopy (AFM), Raman/NMR spectroscopy, X-ray scattering and computational chemistry methodologies, Swedish Research Council (2018-2021)

The project develops experimental procedures to probe biobased hybrids in liquid medium/ wet conditions using atomic force microscopy and spectroscopy and in situ X-ray scattering , combined with computational chemistry is envisioned in the project to evaluate and predict the self-assembling between nanocellulose and other nanoparticles and understand how the self-assembled morphologies drive the pore structure formation and adsorption in biobased membarnes and filters used  for water purification.

Mistra, Smart Materials, TERRACLEAN, 2017-2021 www.mistraterraclean.com

With a vision to address global sustainability challenges, the Mistra TerraClean program will use naturally occurring and commercially important raw materials indigenous to Sweden, such as (nano)cellulose and mesoporous inorganic materials invented and developed in Sweden, to develop smart materials for removal of chemical wastes and pollutants from ambient water and air in the environment and industrial effluents. 

H2020 ,NanoTextsurf, 2017-2020. www.nanotextsurf.eu

The NanoTextSurf project, a 3-year project launched in November 2017, focuses on manufacturing technologies of the nanotextued surfaces  for membarnes,  textiles, abrasion materials and friction materials with nano-scaled materials as nanocellulose . The goal is to upgrade and optimize existing pilot lines, and use them to demonstrate  the scalability of novel nanotextured surfaces.

Biobased scaffolds, membranes and hydrogels for imporved wound healing and bone regeneration (Bioheal) Swedish Research Links, International collaboration: 2017-2020

The aim of the project is to establish a fruitful collaboration and exchange of knowledge/expertise between Swedish and Indian material scientists and medical team to develop polymer based bioglass scaffold, cellulose nanocomposite membranes and hydrogels for wound and dental care and also joint supervision of a PhD students and master students.

Earlier fundings 

Project Co-ordinator: FP7-NMP-2011-SMALL-5, Proposal reference number: 280519-2 2011, Budget: 4M €uros, Co-ordinator, 2012-2016

Principal Investigator: Wallenberg Wood Science Centre Funding, Functional Materials Research at Stockholm University, 2015-2019 ; Stockholm University Faculty support, 2015- 2019  ; VR  2013, 2014- 2017.; Swedish research links, International collaborative research grants, South Africa, 2009-2011, Swedish research links, International collaborative research grants,  India; 2009-2011, Nanomembran för rening av gaser och vätskor, Innovationsbron, (2009) 

Partner: CEREAL (ERANET-SUSFOOD, 2014- 2017; n-POSSCOG , no: 2011-02071
 MNT-ERA.NET Transnational Call 2011.

Publikationer

I urval från Stockholms universitets publikationsdatabas
  • 2020. Andrea Aguilar-Sanchez (et al.). Journal of Membrane Science

    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 Mw 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.

  • 2020. Chuantao Zhu, Susanna Monti, Aji P. Mathew. Carbohydrate Polymers 229

    Atomic Force Microscope (AFM) probes were successfully functionalized with two types of nanocellulose, namely 2,2,6,6-tetramethylpiperidine-1-oxylradical (TEMPO)-mediated oxidized cellulose nanofibers (TOCNF) and cellulose nanocrystals (CNC) and used to study interfacial interactions of nanocellulose with Cu(II) ions and the Victoria blue B dye in liquid medium. TOCNF modified tip showed higher adhesion force due to adsorption of Cu(II) ions and dye molecules compared to CNC ones. Exploring the adsorption properties through classical reactive molecular dynamics simulations (ReaxFF) at the atomic scale confirmed that the Cu(II) ions promptly migrated and adsorbed onto the nanocelluloses through the co-operative chelating action of carboxyl and hydroxyl species. The adsorbed Cu(II) ions showed the tendency to self-organize by forming nano-clusters of variable size, whereas the dye adopted a flat orientation to maximize its adsorption. The satisfactory agreement between the two techniques suggests that functionalized AFM probes can be successfully used to study nanocellulose surface interactions in dry or aqueous environment.

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

    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.

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

    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.

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

    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.

Visa alla publikationer av Aji Mathew vid Stockholms universitet

Senast uppdaterad: 30 november 2020

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