Preparation of cellulose-based filtration membranes with stimuli-responsive properties: Master's thesis

Minna Hakalahti

    Research output: ThesisMaster's thesis

    Abstract

    Membranes are major components of many water-intensive industrial processes. Fouling, one of membrane technology's main challenges, decreases permeability and increases the need for cleaning. Anti-fouling properties of membranes can be enhanced for example by surface treatment by chemical modification. Additionally, smart cleaning behaviour can be achieved by incorporating stimuli-responsive polymers onto filtration membrane surfaces. When fouling occurs, membrane pores can be temporarily and reversibly enlarged by an external stimulus to aid cleaning. In this study, polysaccharides were chemically modified by adding allylic double bonds to their backbone. Furthermore, these highly reactive double bonds were used for crosslinking and grafting poly(N-isopropylacrylamide) (PNIPAM) to integrate a temperature-responsive property. Hydrogel and membrane samples were prepared. 13C NMR, SEM, chromatographic bromine analysis, DSC, elementary analysis and CR-filtration tests were used to characterize prepared samples. Results of this study demonstrated that cellulosic materials were modified into cellulosic derivatives containing moderate amounts of allyl double bonds. These derivatives were capable of crosslinking and could be grafted with PNIPAM with high grafting efficiencies. LCST of PNIPAM altered slightly depending on the matrix material. Commercial membranes and filter materials were modified by applying these cellulosic derivatives. Stable coatings that changed the surface morphologies were formed, but a temperature-response was not observed around the LCST of PNIPAM in permeability measurements.
    Original languageEnglish
    QualificationMaster Degree
    Awarding Institution
    • Aalto University
    Place of PublicationEspoo
    Publisher
    Publication statusPublished - 2013
    MoE publication typeG2 Master's thesis, polytechnic Master's thesis

    Fingerprint

    Cellulose
    Membranes
    Cleaning
    Fouling
    Derivatives
    Crosslinking
    Bromine
    Membrane technology
    Membrane fouling
    Hydrogel
    Chemical modification
    Surface morphology
    Polysaccharides
    Surface treatment
    Polymers
    Nuclear magnetic resonance
    Coatings
    Temperature
    Scanning electron microscopy
    poly-N-isopropylacrylamide

    Keywords

    • stimuli-responsive poymers
    • filtration membranes
    • cellulose
    • grafting
    • surface functionalization
    • PNIPAM

    Cite this

    @phdthesis{be4ed4f06eb248bda1b4f5d38a9a1e45,
    title = "Preparation of cellulose-based filtration membranes with stimuli-responsive properties: Master's thesis",
    abstract = "Membranes are major components of many water-intensive industrial processes. Fouling, one of membrane technology's main challenges, decreases permeability and increases the need for cleaning. Anti-fouling properties of membranes can be enhanced for example by surface treatment by chemical modification. Additionally, smart cleaning behaviour can be achieved by incorporating stimuli-responsive polymers onto filtration membrane surfaces. When fouling occurs, membrane pores can be temporarily and reversibly enlarged by an external stimulus to aid cleaning. In this study, polysaccharides were chemically modified by adding allylic double bonds to their backbone. Furthermore, these highly reactive double bonds were used for crosslinking and grafting poly(N-isopropylacrylamide) (PNIPAM) to integrate a temperature-responsive property. Hydrogel and membrane samples were prepared. 13C NMR, SEM, chromatographic bromine analysis, DSC, elementary analysis and CR-filtration tests were used to characterize prepared samples. Results of this study demonstrated that cellulosic materials were modified into cellulosic derivatives containing moderate amounts of allyl double bonds. These derivatives were capable of crosslinking and could be grafted with PNIPAM with high grafting efficiencies. LCST of PNIPAM altered slightly depending on the matrix material. Commercial membranes and filter materials were modified by applying these cellulosic derivatives. Stable coatings that changed the surface morphologies were formed, but a temperature-response was not observed around the LCST of PNIPAM in permeability measurements.",
    keywords = "stimuli-responsive poymers, filtration membranes, cellulose, grafting, surface functionalization, PNIPAM",
    author = "Minna Hakalahti",
    note = "BA3155 64 p. + app. 7 p.",
    year = "2013",
    language = "English",
    publisher = "Aalto University",
    address = "Finland",
    school = "Aalto University",

    }

    Preparation of cellulose-based filtration membranes with stimuli-responsive properties : Master's thesis. / Hakalahti, Minna.

    Espoo : Aalto University, 2013. 71 p.

    Research output: ThesisMaster's thesis

    TY - THES

    T1 - Preparation of cellulose-based filtration membranes with stimuli-responsive properties

    T2 - Master's thesis

    AU - Hakalahti, Minna

    N1 - BA3155 64 p. + app. 7 p.

    PY - 2013

    Y1 - 2013

    N2 - Membranes are major components of many water-intensive industrial processes. Fouling, one of membrane technology's main challenges, decreases permeability and increases the need for cleaning. Anti-fouling properties of membranes can be enhanced for example by surface treatment by chemical modification. Additionally, smart cleaning behaviour can be achieved by incorporating stimuli-responsive polymers onto filtration membrane surfaces. When fouling occurs, membrane pores can be temporarily and reversibly enlarged by an external stimulus to aid cleaning. In this study, polysaccharides were chemically modified by adding allylic double bonds to their backbone. Furthermore, these highly reactive double bonds were used for crosslinking and grafting poly(N-isopropylacrylamide) (PNIPAM) to integrate a temperature-responsive property. Hydrogel and membrane samples were prepared. 13C NMR, SEM, chromatographic bromine analysis, DSC, elementary analysis and CR-filtration tests were used to characterize prepared samples. Results of this study demonstrated that cellulosic materials were modified into cellulosic derivatives containing moderate amounts of allyl double bonds. These derivatives were capable of crosslinking and could be grafted with PNIPAM with high grafting efficiencies. LCST of PNIPAM altered slightly depending on the matrix material. Commercial membranes and filter materials were modified by applying these cellulosic derivatives. Stable coatings that changed the surface morphologies were formed, but a temperature-response was not observed around the LCST of PNIPAM in permeability measurements.

    AB - Membranes are major components of many water-intensive industrial processes. Fouling, one of membrane technology's main challenges, decreases permeability and increases the need for cleaning. Anti-fouling properties of membranes can be enhanced for example by surface treatment by chemical modification. Additionally, smart cleaning behaviour can be achieved by incorporating stimuli-responsive polymers onto filtration membrane surfaces. When fouling occurs, membrane pores can be temporarily and reversibly enlarged by an external stimulus to aid cleaning. In this study, polysaccharides were chemically modified by adding allylic double bonds to their backbone. Furthermore, these highly reactive double bonds were used for crosslinking and grafting poly(N-isopropylacrylamide) (PNIPAM) to integrate a temperature-responsive property. Hydrogel and membrane samples were prepared. 13C NMR, SEM, chromatographic bromine analysis, DSC, elementary analysis and CR-filtration tests were used to characterize prepared samples. Results of this study demonstrated that cellulosic materials were modified into cellulosic derivatives containing moderate amounts of allyl double bonds. These derivatives were capable of crosslinking and could be grafted with PNIPAM with high grafting efficiencies. LCST of PNIPAM altered slightly depending on the matrix material. Commercial membranes and filter materials were modified by applying these cellulosic derivatives. Stable coatings that changed the surface morphologies were formed, but a temperature-response was not observed around the LCST of PNIPAM in permeability measurements.

    KW - stimuli-responsive poymers

    KW - filtration membranes

    KW - cellulose

    KW - grafting

    KW - surface functionalization

    KW - PNIPAM

    M3 - Master's thesis

    PB - Aalto University

    CY - Espoo

    ER -