Nanocellulose / Nanocarbon Composites for Direct Electrochemical Detection of Small Molecules

Vasuki Durairaj

Nanocellulose / Nanocarbon Composites for Direct Electrochemical Detection of Small Molecules

Julkaisun otsikon käännös: Nanoselluloosa/nanohiilikomposiitit pienten molekyylien suoraan sähkökemialliseen havaitsemiseen

Vasuki Durairaj

Tutkimustuotos: Doctoral Thesis › Collection of Articles

Abstrakti

Nanoselluloosamateriaalit ovat nopeasti kehittymässä monipuoliseksi ja kestäväksi synteettisten polymeerien korvaajaksi useissa korkean lisäarvon sovelluksissa. Erityisen kiinnostava sovellusalue on erilaiset anturit, joissa nanoselluloosan käyttöä puoltavat sen ainutlaatuiset materiaaliominaisuudet: suuri lujuus ja ominaispinta-ala, laajalti kartoitetut kemialliset muokkausmekanismit, hygroskooppisuus sekä taipumus muodostaa kalvoja. Lisäksi nanoselluloosan kyky dispergoida hiilinanomateriaaleja stabiileihin vesisuspensioihin on mahdollistanut viime vuosina nanoselluloosa/nanohiili-pohjaisten sähkökemiallisten alustojen kehittämisen erilaisten lääkkeiden ja biomolekyylien havaitsemiseksi.Tämä ala on kuitenkin vielä lapsenkengissään, ja lisää ymmärrystä tarvitaan eri nanoselluloosamateriaalien vaikutuksesta syntyvien nanoselluloosa/nanohiilikomposiittien elektroanalyyttiseen suorituskykyyn. Tässä opinnäytetyössä olemme valmistaneet komposiittielektrodirakenteita yhdistämällä muodoltaan ja funktionaalisuudeltaan erilaisiananoselluloosamateriaaleja kaupallisten moniseinäisten hiilinanoputkien (MWCNT) kanssa. Nanoselluloosamateriaalien, MWCNT:n ja näitä yhdistävien komposiittien fysikaalista ja kemiallista luonnetta on tutkittu useilla pinta- ja bulkkikarakterisointimenetelmillä. Komposiittien ominaisuuksien on havaittu korreloivan niiden sähkökemiallisen suorituskyvyn kanssa, jota on arvioitu sekä ulko- että sisäkehän redox-molekyylejä käyttämällä. Olemme osoittaneet, että niin eri tavoin pintafunktionalisoituja selluloosan nanokiteitä (CNC) kuin selluloosan nanofibrillejäkin (CNF) voidaan käyttää MWCNT:n kanssa erittäin stabiilien ja kestävien sähkökemiallisten alustojen valmistamiseen vaarantamatta MWCNT:n sähkökemiallista aktiivisuutta. Nanoselluloosan muodolla on osoitettu olevan merkittävä vaikutus komposiittimorfologiaan; tiheästi funktionalisoidun CNF:n käyttö johtaa avoimiin rakenteisiin, joissa on enemmän esillä olevaa MWCNT-pintaa, kun taas CNC:n käyttö johtaa tiheämpiin rakenteisiin, joissa CNC on pakkautuneena tiiviisti MWCNT:n ympärille. Vastaavasti CNF-pohjaisilla komposiiteilla on suurempi sähkökemiallisesti aktiivinen pinta-ala, lisääntyneet sähköstaattiset vuorovaikutukset ja voimakkaammat redox-virrat kaikille mitatuille analyyteille. Nanoselluloosan funktionalisoinnin luonteen ja määrän on osoitettu vaikuttavan merkittävästi komposiitin sähköstaattisten vuorovaikutusten voimakkuuteen, mikä tarjoaa mahdollisuuksia ionisen selektiivisyyden räätälöintiin. Lopuksi olemme osoittaneet, että kaikki tässä työssä ehdotetut nanoselluloosa / MWCNT-komposiitit pystyvät saavuttamaan huomattavasti korkeamman herkkyyden ja selektiivisyyden kationiselle sisäkehän redox-molekyylille, kuten dopamiinille, verrattuna nykyisiin kaupallisiin MWCNT-pohjaisiin standardielektrodeihin.

Julkaisun otsikon käännös	Nanoselluloosa/nanohiilikomposiitit pienten molekyylien suoraan sähkökemialliseen havaitsemiseen
Alkuperäiskieli	Englanti
Pätevyys	Tohtorintutkinto
Myöntävä instituutio	Aalto-yliopisto
Valvoja/neuvonantaja	Koskinen, Jari, Vastuuprofessori Laurila, Tomi, Ohjaaja
Kustantaja	Aalto University
Painoksen ISBN	978-952-64-1024-1
Sähköinen ISBN	978-952-64-1025-8
Tila	Julkaistu - 2022
OKM-julkaisutyyppi	G5 Artikkeliväitöskirja

Tutkimusalat

nanoselluloosa
hiilinanoputket
sähkökemialliset anturit

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http://urn.fi/URN:ISBN:978-952-64-1025-8

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@phdthesis{5c75ad382aed46469921c3dacdfb6e7a,

title = "Nanocellulose / Nanocarbon Composites for Direct Electrochemical Detection of Small Molecules",

abstract = "Nanocellulosic materials are rapidly developing into highly versatile and sustainable alternatives for synthetic polymers in several high value applications. They are of particular interest in various sensor architectures due to their unique properties such as high strength, large surface area with potential for functionalization, hygroscopicity and film forming tendency. Further, their ability to disperse carbon nanomaterials in stable aqueous suspensions has resulted in an increased interest towards the development of nanocellulose / nanocarbon electrochemical platforms for detection of various drugs and biomolecules in the recent years. However, this field is still in its infancy, and there is an evident need to understand the role of different nanocellulosic materials in tailoring the electroanalytical performance of the resultant nanocellulose / nanocarbon composites. In this thesis, we have used nanocellulosic materials with different geometries and functionalizations, to develop composite electrode architectures with commercial multiwalled carbon nanotubes (MWCNT). The physical and chemical nature of the nanocellulosic materials, MWCNT, and their composites, are studied using several surface and bulk characterization methods and are correlated to the electrochemical performances of the composites evaluated using both outer and inner sphere redox molecules. We have shown that both cellulose nanocrystals (CNC) and cellulose nanofibrils (CNF) having different surface functionalizations, can be used to develop highly stable, robust electrochemical platforms with MWCNT, without compromising the electrochemical activity of the MWCNT. The nanocellulose geometry is clearly demonstrated to have a significant effect upon the composite morphology, where the highly functionalized CNFs result in open architectures with more exposed MWCNT surface, and CNCs result in denser architectures with the CNC packed closely around the MWCNT. Correspondingly, the CNF-based composites exhibit higher electrochemically active surface area, increased electrostatic effects and stronger redox currents for all measured analytes. The nature and degree of nanocellulose functionalization is shown to have a significant effect on the extent of electrostatic effects in the composite, offering a promising route towards tailoring the ionics electivity. Finally, we demonstrate that all the nanocellulose / MWCNT composites proposed in this work are capable of achieving significantly higher sensitivity and selectivity towards a cationic inner sphere redox molecule such as dopamine, compared to current commercial standard MWCNT electrodes.",

keywords = "nanocellulose, carbon nanotubes, MWCNT, composites, electrochemical sensors, nanoselluloosa, hiilinanoputket, s{\"a}hk{\"o}kemialliset anturit, nanocellulose, carbon nanotubes, MWCNT, composites, electrochemical sensors",

author = "Vasuki Durairaj",

year = "2022",

language = "English",

isbn = "978-952-64-1024-1",

series = "Aalto University publication series DOCTORAL THESES",

publisher = "Aalto University",

number = "169",

address = "Finland",

school = "Aalto University",

}

TY - BOOK

T1 - Nanocellulose / Nanocarbon Composites for Direct Electrochemical Detection of Small Molecules

AU - Durairaj, Vasuki

PY - 2022

Y1 - 2022

N2 - Nanocellulosic materials are rapidly developing into highly versatile and sustainable alternatives for synthetic polymers in several high value applications. They are of particular interest in various sensor architectures due to their unique properties such as high strength, large surface area with potential for functionalization, hygroscopicity and film forming tendency. Further, their ability to disperse carbon nanomaterials in stable aqueous suspensions has resulted in an increased interest towards the development of nanocellulose / nanocarbon electrochemical platforms for detection of various drugs and biomolecules in the recent years. However, this field is still in its infancy, and there is an evident need to understand the role of different nanocellulosic materials in tailoring the electroanalytical performance of the resultant nanocellulose / nanocarbon composites. In this thesis, we have used nanocellulosic materials with different geometries and functionalizations, to develop composite electrode architectures with commercial multiwalled carbon nanotubes (MWCNT). The physical and chemical nature of the nanocellulosic materials, MWCNT, and their composites, are studied using several surface and bulk characterization methods and are correlated to the electrochemical performances of the composites evaluated using both outer and inner sphere redox molecules. We have shown that both cellulose nanocrystals (CNC) and cellulose nanofibrils (CNF) having different surface functionalizations, can be used to develop highly stable, robust electrochemical platforms with MWCNT, without compromising the electrochemical activity of the MWCNT. The nanocellulose geometry is clearly demonstrated to have a significant effect upon the composite morphology, where the highly functionalized CNFs result in open architectures with more exposed MWCNT surface, and CNCs result in denser architectures with the CNC packed closely around the MWCNT. Correspondingly, the CNF-based composites exhibit higher electrochemically active surface area, increased electrostatic effects and stronger redox currents for all measured analytes. The nature and degree of nanocellulose functionalization is shown to have a significant effect on the extent of electrostatic effects in the composite, offering a promising route towards tailoring the ionics electivity. Finally, we demonstrate that all the nanocellulose / MWCNT composites proposed in this work are capable of achieving significantly higher sensitivity and selectivity towards a cationic inner sphere redox molecule such as dopamine, compared to current commercial standard MWCNT electrodes.

AB - Nanocellulosic materials are rapidly developing into highly versatile and sustainable alternatives for synthetic polymers in several high value applications. They are of particular interest in various sensor architectures due to their unique properties such as high strength, large surface area with potential for functionalization, hygroscopicity and film forming tendency. Further, their ability to disperse carbon nanomaterials in stable aqueous suspensions has resulted in an increased interest towards the development of nanocellulose / nanocarbon electrochemical platforms for detection of various drugs and biomolecules in the recent years. However, this field is still in its infancy, and there is an evident need to understand the role of different nanocellulosic materials in tailoring the electroanalytical performance of the resultant nanocellulose / nanocarbon composites. In this thesis, we have used nanocellulosic materials with different geometries and functionalizations, to develop composite electrode architectures with commercial multiwalled carbon nanotubes (MWCNT). The physical and chemical nature of the nanocellulosic materials, MWCNT, and their composites, are studied using several surface and bulk characterization methods and are correlated to the electrochemical performances of the composites evaluated using both outer and inner sphere redox molecules. We have shown that both cellulose nanocrystals (CNC) and cellulose nanofibrils (CNF) having different surface functionalizations, can be used to develop highly stable, robust electrochemical platforms with MWCNT, without compromising the electrochemical activity of the MWCNT. The nanocellulose geometry is clearly demonstrated to have a significant effect upon the composite morphology, where the highly functionalized CNFs result in open architectures with more exposed MWCNT surface, and CNCs result in denser architectures with the CNC packed closely around the MWCNT. Correspondingly, the CNF-based composites exhibit higher electrochemically active surface area, increased electrostatic effects and stronger redox currents for all measured analytes. The nature and degree of nanocellulose functionalization is shown to have a significant effect on the extent of electrostatic effects in the composite, offering a promising route towards tailoring the ionics electivity. Finally, we demonstrate that all the nanocellulose / MWCNT composites proposed in this work are capable of achieving significantly higher sensitivity and selectivity towards a cationic inner sphere redox molecule such as dopamine, compared to current commercial standard MWCNT electrodes.

KW - nanocellulose

KW - carbon nanotubes

KW - MWCNT

KW - composites

KW - electrochemical sensors

KW - nanoselluloosa

KW - hiilinanoputket

KW - sähkökemialliset anturit

KW - nanocellulose

KW - carbon nanotubes

KW - MWCNT

KW - composites

KW - electrochemical sensors

M3 - Doctoral Thesis

SN - 978-952-64-1024-1

T3 - Aalto University publication series DOCTORAL THESES

PB - Aalto University

ER -

Nanocellulose / Nanocarbon Composites for Direct Electrochemical Detection of Small Molecules

Abstrakti

Tutkimusalat

Pääsy asiakirjaan

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