Change search
Link to record
Permanent link

Direct link
BETA
Publications (10 of 10) Show all publications
Ottenhall, A. (2018). Antimicrobial materials from cellulose using environmentally friendly techniques. (Doctoral dissertation). KTH Royal Institute of Technology
Open this publication in new window or tab >>Antimicrobial materials from cellulose using environmentally friendly techniques
2018 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

The transition to a more biobased society introduces both new opportunities and new challenges as we replace nonrenewable materials with renewable alternatives. One important challenge will be to control microbial growth on materials, both to protect the materials from biological degradation and to prevent the spread of infections and toxins that can cause illness.

In this thesis, both existing and new types of cellulose-based materials were treated with environmentally friendly alternatives to usual biocides to prevent microbial growth and remove bacteria from water. Two types of antimicrobial systems were studied, and the antimicrobial effects were evaluated for bacteria and fungi using both model organisms and wild-type cultures.

The first antimicrobial approach employed was a nonleaching and contact-active layer-by-layer adsorption of polyelectrolytes to provide the cellulose fibers with a cationic surface charge, which attracts and captures bacteria onto the fiber surface. The study showed that paper filters with pores much larger than bacteria could remove more than 99.9 % of E. coli from water when used in filtration mode. The polyelectrolyte-modified materials showed a good antibacterial effect but did not prevent fungal growth.

The second approach was to utilize biobased compounds with antimicrobial properties, which were applied to cellulose fiber foam materials. Chitosan and extractives from birch bark were selected as biobased options for antimicrobial agents. Two types of cellulose fiber foam materials were developed and evaluated for their antimicrobial properties.

This thesis shows the importance of understanding both the application and the targeted microorganism when selecting an environmentally friendly antimicrobial system for treating biobased materials. It highlights that a good understanding of both material science and microbiology is important when designing new antimicrobial materials.

Abstract [sv]

Satsningen på ett mer biobaserat samhälle, där vi ersätter icke-förnybara material med förnyelsebara alternativ, är en pusselbit för en mer hållbar framtid samtidigt som den medför nya utmaningar. En viktig uppgift är att minska och kontrollera mikrobiell tillväxt, både för att skydda material från biologisk nedbrytning men också för att förhindra spridning av infektioner och toxiner.

Cellulosabaserade material har behandlats med miljövänliga alternativ till traditionella biocider för att förhindra mikrobiell tillväxt och för ta bort bakterier från vatten. Två typer av antimikrobiella system har använts varefter den antimikrobiella effekten mot både mögel och bakterier utvärderats, med hjälp av både modellorganismer och mikrobiella odlingar från naturen.

Den första typen av antimikrobiell metod som använts baseras på en kontakt-aktivt teknik. Cellulosafibrer har modifierats genom lager-på-lager polyelektrolytadsorption för att skapa en positiv ytladdning som kan attrahera och binda bakterier till fiberytan. Studien visar att modifierade pappersfilter, med porer som är mycket större än bakterier, kan filtrera bort mer än 99,9 % av E. coli från kontaminerat vatten. De polyelektrolyt-modifierade cellulosamaterialen påvisade goda antibakteriella egenskaper men förhindrade inte tillväxt av mögel.

Den andra metoden som undersökts var att tillsätta biobaserade ämnen med antimikrobiella egenskaper till cellulosabaserade fiberskum. Kitosan och extraktivämnen från björkbark valdes ut som miljövänliga alternativ till vanliga biocider. Två typer av cellulosabaserade fiberskum har tagits fram och utvärderats för deras antimikrobiella egenskaper.

Avhandlingen visar hur viktigt det är att veta hur materialet är tänkt att användas och vilken typ av mikroorganism som skall undvikas när man väljer antimikrobiell behandling av biobaserade material. God förståelse för både materialvetenskap och mikrobiologi är nödvändig när nya biobaserade material med antimikrobiella egenskaper skall designas.

Place, publisher, year, edition, pages
KTH Royal Institute of Technology, 2018. p. 68
Series
TRITA-CBH-FOU ; 2018:57
Keywords
Antibacterial, antifungal, cellulosic, mold, bacteria, biobased, bio-based, renewable, insulation, packaging, water treatment, water purification, paper filter, paper, membrane, Antibakteriell, fungicid, mögel, antimögel, pappersfilter, vattenrening, membran, papper, bakterier, cellulosa, förpackning, isolering, förnyelsebar, biobaserade, nya material
National Category
Paper, Pulp and Fiber Technology Water Treatment Microbiology
Research subject
Fibre and Polymer Science
Identifiers
urn:nbn:se:kth:diva-238843 (URN)978-91-7873-031-5 (ISBN)
Public defence
2018-12-07, F3, Lindstedtsvägen 26, KTH Campus, Stockholm, 14:00 (English)
Opponent
Supervisors
Funder
ÅForsk (Ångpanneföreningen's Foundation for Research and Development), 17-391Swedish Research Council Formas, 2014-00959
Note

QC 20181114

Available from: 2018-11-14 Created: 2018-11-12 Last updated: 2018-11-14Bibliographically approved
Ottenhall, A., Henschen, J., Illergård, J. & Ek, M. (2018). Cellulose-based water purification using paper filters modified with polyelectrolyte multilayers to remove bacteria from water through electrostatic interactions. Environmental Science: Water Research & Technology
Open this publication in new window or tab >>Cellulose-based water purification using paper filters modified with polyelectrolyte multilayers to remove bacteria from water through electrostatic interactions
2018 (English)In: Environmental Science: Water Research & Technology, ISSN 2053-1400Article in journal (Refereed) Published
Abstract [en]

Filtration is a common way to obtain pure drinking water by removing particles and microorganisms based on size exclusion. Cellulose-based filters are affordable and biobased option for the removal of particles but bacteria are usually too small to be removed by size exclusion alone. In this article, the surfaces of cellulose fibres in two types of commercial paper filters have been given a positive net charge to trap bacteria through electrostatic interactions without releasing any biocides. The fibres were modified with the cationic polyelectrolyte polyvinylamine polymer in single layers (1 L) or in multilayers together with the anionic polyelectrolyte polyacrylic acid (3 L or 5 L) using a water-based process at room temperature. Filtration tests show that all filters, using both types of filter papers and a number of layers, can physically remove more than 99.9% of E. coli from water and that the 3 L modified filters can remove more than 97% of cultivatable bacteria from natural water samples. The bacterial reduction increased with increasing number of filter sheets used for the filtration and the majority of the bacteria were trapped in the top sheets of the filter. The results show the potential for creating water purification filters from bio-based everyday consumable products with a simple modification process. The filters could be used in the future for point-of-use water purification that may be able to save lives without releasing bactericides.

Keywords
Cellulose, water treatment, paper filter, membrane, filter, antibacterial, remove bacteria, layer-by-layer, Cellulosa, pappersfilter, vattenrening, membran, lager-på-lager, antibakteriell
National Category
Water Treatment
Research subject
Fibre and Polymer Science
Identifiers
urn:nbn:se:kth:diva-238838 (URN)10.1039/C8EW00514A (DOI)000451072500017 ()2-s2.0-85057384523 (Scopus ID)
Funder
ÅForsk (Ångpanneföreningen's Foundation for Research and Development), 17-391
Note

QC 20181112

Available from: 2018-11-12 Created: 2018-11-12 Last updated: 2019-08-27Bibliographically approved
Ottenhall, A., Seppänen, T. & Ek, M. (2018). Water-stable cellulose fiber foam with antimicrobial properties for bio based low-density materials. Cellulose (London), 25(4), 2599-2613
Open this publication in new window or tab >>Water-stable cellulose fiber foam with antimicrobial properties for bio based low-density materials
2018 (English)In: Cellulose (London), ISSN 0969-0239, E-ISSN 1572-882X, Vol. 25, no 4, p. 2599-2613Article in journal (Refereed) Published
Abstract [en]

New bio-based packaging materials are highly interesting for replacing conventional fossil based products for a more sustainable society. Water-stable cellulose fiber foams have been produced in a simple one-batch foam-forming process with drying under ambient conditions. The cellulose fiber foams have a low density (33–66 kg/m3) and can inhibit microbial growth; two highly valuable features for insulating packaging materials, especially in combination with stability in water. Cationic chitosan and/or polyvinylamine have been added during the foam-forming process to give the foams water-stability and antimicrobial properties. The structural and mechanical properties of the cellulose fiber foams have been studied and the antimicrobial properties have been evaluated with respect to both Escherichia coli, a common model bacteria and Aspergillus brasiliensis, a sporulating mold. The cellulose foams containing chitosan had both good water-stability and good antibacterial and antifungal properties, while the foams containing PVAm did disintegrate in water and did not inhibit fungal growth when nutrients were added to the foam, showing that it is possible to produce a bio-based foam material with the desired characters. This can be an interesting low-density packaging material for protection from both mechanical and microbial damage without using any toxic compounds.

Place, publisher, year, edition, pages
Springer Netherlands, 2018
Keywords
Antibacterial, Antifungal, Cellulosic, Chitosan, Citric acid, Insulation, Packaging, Polyvinylamine, Wet-stable
National Category
Polymer Technologies
Identifiers
urn:nbn:se:kth:diva-227639 (URN)10.1007/s10570-018-1738-y (DOI)000428925300032 ()2-s2.0-85042912355 (Scopus ID)
Note

QC 20180509

Available from: 2018-05-09 Created: 2018-05-09 Last updated: 2018-11-12Bibliographically approved
Ottenhall, A., Seppänen, T. & Ek, M. (2017). Purification of water using cellulose: A safe way to remove bacteria. Paper presented at 253rd National Meeting of the American-Chemical-Society (ACS) on Advanced Materials, Technologies, Systems, and Processes, APR 02-06, 2017, San Francisco, CA. Abstracts of Papers of the American Chemical Society, 253
Open this publication in new window or tab >>Purification of water using cellulose: A safe way to remove bacteria
2017 (English)In: Abstracts of Papers of the American Chemical Society, ISSN 0065-7727, Vol. 253Article in journal, Meeting abstract (Other academic) Published
Place, publisher, year, edition, pages
AMER CHEMICAL SOC, 2017
National Category
Organic Chemistry
Identifiers
urn:nbn:se:kth:diva-242594 (URN)000430568503482 ()
Conference
253rd National Meeting of the American-Chemical-Society (ACS) on Advanced Materials, Technologies, Systems, and Processes, APR 02-06, 2017, San Francisco, CA
Note

QC 20190226

Available from: 2019-02-26 Created: 2019-02-26 Last updated: 2019-08-20Bibliographically approved
Ottenhall, A., Illergård, J. & Ek, M. (2017). Water Purification Using Functionalized Cellulosic Fibers with Nonleaching Bacteria Adsorbing Properties. Environmental Science and Technology, 51, 7616-7623
Open this publication in new window or tab >>Water Purification Using Functionalized Cellulosic Fibers with Nonleaching Bacteria Adsorbing Properties
2017 (English)In: Environmental Science and Technology, ISSN 0013-936X, E-ISSN 1520-5851, Vol. 51, p. 7616-7623Article in journal (Refereed) Published
Abstract [en]

Portable purification systems are easy ways to obtain clean drinking water when there is no large-scale water treatment available. In this study, the potential to purify water using bacteria adsorbing cellulosic fibers, functionalized with polyelectrolytes according to the layer-by-layer method, is investigated. The adsorbed polyelectrolytes create a positive charge on the fiber surface that physically attracts and bonds with bacteria. Three types of cellulosic materials have been modified and tested for the bacterial removal capacity in water. The time, material-water ratio and bacterial concentration dependence, as well as the bacterial removal capacity in water from natural sources, have been evaluated. Freely dispersed bacteria adsorbing cellulosic fibers can remove greater than 99.9% of Escherichia coli from nonturbid water, with the most notable reduction occurring within the first hour. A filtering approach using modified cellulosic fibers is desirable for purification of natural water. An initial filtration test showed that polyelectrolyte multilayer modified cellulosic fibers can remove greater than 99% of bacteria from natural water. The bacteria adsorbing cellulosic fibers do not leach any biocides, and it is an environmentally sustainable and cheap option for disposable water purification devices.

Place, publisher, year, edition, pages
American Chemical Society (ACS), 2017
Keywords
Water treatment, membrane, filter, cellulose, cationic, contact-active, antibacterial, paper, Point-of-Use, polyelectrolyte, layer-by-layer, Vattenrening, pappersfilter, filter, cellulosa, kontaktaktiv, antibakteriell, positiv laddning, lager-på-lager, polyelektrolytmodifiering
National Category
Water Treatment
Research subject
Fibre and Polymer Science
Identifiers
urn:nbn:se:kth:diva-238837 (URN)10.1021/acs.est.7b01153 (DOI)
Note

QC 20181112

Available from: 2018-11-12 Created: 2018-11-12 Last updated: 2018-11-12Bibliographically approved
Ottenhall, A., Ek, M. & Illergård, J. (2017). Water Purification Using Functionalized Cellulosic Fibers with Nonleaching Bacteria Adsorbing Properties. Environmental Science and Technology, 13, 7616-7623
Open this publication in new window or tab >>Water Purification Using Functionalized Cellulosic Fibers with Nonleaching Bacteria Adsorbing Properties
2017 (English)In: Environmental Science and Technology, ISSN 0013-936X, E-ISSN 1520-5851, Vol. 13, p. 7616-7623Article in journal (Refereed) Published
Abstract [en]

 Portable purifi cation systems are easy ways to obtain clean drinking water when there is no large-scale water treatment available. In this study, the potential to purify water using bacteria adsorbing cellulosic fi bers, functionalized with polyelectrolytes according to the layer-by-layer method, is investigated. The adsorbed polyelectrolytes create a positive charge on the fi ber surface that physically attracts and bonds with bacteria. Three types of cellulosic materials have been modifi ed and tested for the bacterial removal capacity in water. The time, material-water ratio and bacterial concentration dependence, as well as the bacterial removal capacity in water from natural sources, have been evaluated. Freely dispersed bacteria adsorbing cellulosic fi bers can remove greater than 99.9% of Escherichia coli  from nonturbid water, with the most notable reduction occurring within the fi rst hour. A fi ltering approach using modifi ed cellulosic fi bers is desirable for purifi cation of natural water. An initial fi ltration test showed that polyelectrolyte multilayer modifi ed cellulosic fi bers can remove greater than 99% of bacteria from natural water. The bacteria adsorbing cellulosic fi bers do not leach any biocides, and it is an environmentally sustainable and cheap option for disposable water purification devices.

Place, publisher, year, edition, pages
American Chemical Society (ACS), 2017
Keywords
cellulose, water treatment, water purification, layer by layer, multilayer adsorption, bacteria removing, Vattenrening, cellulosa, pappersmassa, multilager, bakterieadsorption
National Category
Paper, Pulp and Fiber Technology
Research subject
Fibre and Polymer Science
Identifiers
urn:nbn:se:kth:diva-218668 (URN)10.1021/acs.est.7b01153 (DOI)000405056200035 ()2-s2.0-85024408693 (Scopus ID)
Note

QC 20171204

Available from: 2017-11-30 Created: 2017-11-30 Last updated: 2018-11-12Bibliographically approved
Ottenhall, A. (2017). Water purification using polyelectrolyte modified cellulose fibers and filters to adsorb bacteria. (Licentiate dissertation). Stockholm: Kungliga Tekniska högskolan
Open this publication in new window or tab >>Water purification using polyelectrolyte modified cellulose fibers and filters to adsorb bacteria
2017 (English)Licentiate thesis, comprehensive summary (Other academic)
Abstract [en]

Clean water is necessary for human survival and there is a need for development of cheap and easy water purification techniques to use in emergency situations when there is no access to safe drinking water. Bacteria contaminated water can cause lethal diarrheal diseases and is globally the second most common cause of death among children less than five years of age.

Bacteria adsorbing filter paper made from cellulose could be an environmentally and economically sustainable alternative for disposable water purification filters. This thesis investigates the possibility to use polyelectrolyte multilayer modified cellulose pulp fibers and filter papers to adsorb and remove bacteria from water. The bacterial removal efficiency of the modified materials has been tested both in suspension and through filtration.

The surface modification provides the cellulose fibers with a positively charged surface that can attract and bind the negatively charged bacteria. The bacterial adsorption through electrostatic interactions makes it possible to remove bacteria, even when the pore size of the cellulose filters is larger than bacteria. Bacterial reduction tests shows that it is possible to remove over 99.9 % of the bacteria when filtering water through the modified materials. An increased amount of adsorbed cationic polyelectrolyte, polyvinylamine, resulted in an increased bacterial removal capacity. It has also been shown that the bacterial removal efficiency increases with an increased the amount of bacteria adsorbing materials in the filter.

The modified materials have been compared with a commercial product and the filtration efficiency has shown to be greater for the polyelectrolyte-modified materials, under the test conditions used in this thesis. Tests with natural water samples shows that it is important to use a filtration mode to remove particles from the water in combination with the bacterial adsorption, as the particles interfere with the bacterial adsorption.

Abstract [sv]

Säkert dricksvatten är nödvändigt för överlevnad och det finns ett stort behov av att utveckla nya billiga och enkla tekniker för att rena vatten i nödsituationer där det inte finns tillgång till detta. Dricksvatten förorenat av bakterier kan orsaka dödliga diarrésjukdomar och är globalt den näst vanligaste dödsorsaken bland barn under fem år.

Denna avhandling undersöker möjligheten att använda cellulosafibrer och filterpapper, ytmodifierade med multilager av katjoniska polyelektrolyter, för att adsorbera och avlägsna bakterier från vatten. Bakterieradsorberande filterpapper tillverkat av cellulosa kan vara ett miljövänligt och ekonomiskt hållbart alternativ för vattenreningsfilter för engångsbruk. De modifierade materialens förmåga att adsorbera bakterier har testats både i suspension och via filtrering.

Ytmodifieringen ger cellulosafibrerna en positivt laddad yta som kan attrahera och binda de negativt laddade bakterierna. Avlägsnandet av bakterier genom elektrostatisk interaktion gör det möjligt att ta bort bakterier, även när filtret har en porstorleken som är större än bakterierna.

Bakteriereduktionstesterna visar att det är möjligt att avlägsna mer än 99,9 % av bakterierna vid filtrering genom de modifierade materialen. En ökad mängd adsorberad katjonisk polyelektrolyt, polyvinylamin, resulterade i en ökad bakterieavlägsningskapacitet. Det har också visat sig att effektivitet ökar väsentligt med ökad mängd bakterieadsorberande material i vattenfiltren.

De ytmodifierade materialen har jämförts med en kommersiell produkt för vattenrening med goda resultat. Filtreringstesterna utförda i den här avhandlingen visar att de modifierade materialen tar bort mer bakterier än vad det kommersiella filtret inaktiverar. Tester med naturliga vattenprov visar att det är viktigt att använda filtrering för att avlägsna partiklar från vattnet för att uppnå en önskad bakterieadsorption, eftersom partiklarna påverkar bakterieadsorptionen och minskar effektiviteten hos de bakterieadsorberande materialen

Place, publisher, year, edition, pages
Stockholm: Kungliga Tekniska högskolan, 2017. p. 50
Series
TRITA-CHE-Report, ISSN 1654-1081 ; 2017:18
Keywords
Bacterial adsorption, cellulose filter, Layer-by-Layer, water treatment
National Category
Paper, Pulp and Fiber Technology
Research subject
Fibre and Polymer Science
Identifiers
urn:nbn:se:kth:diva-204511 (URN)978-91-7729-326-2 (ISBN)
Presentation
2017-04-28, K1, Teknikringen 56, Stockholm, 10:00 (English)
Opponent
Supervisors
Note

QC 20170328

Available from: 2017-03-28 Created: 2017-03-27 Last updated: 2017-10-31Bibliographically approved
Ottenhall, A. (2016). Novel method to remove bacteria from drinking water using modified cellulose. Abstract of Papers of the American Chemical Society, 251
Open this publication in new window or tab >>Novel method to remove bacteria from drinking water using modified cellulose
2016 (English)In: Abstract of Papers of the American Chemical Society, ISSN 0065-7727, Vol. 251Article in journal, Meeting abstract (Other academic) Published
Place, publisher, year, edition, pages
AMER CHEMICAL SOC, 2016
National Category
Organic Chemistry
Identifiers
urn:nbn:se:kth:diva-242698 (URN)000431903802350 ()
Note

QC 20190221

Available from: 2019-02-21 Created: 2019-02-21 Last updated: 2019-02-21Bibliographically approved
Ottenhall, A., Seppänen, T. & Ek, M. (2016). Water-stable cellulose fiber foam with antimicrobial properties for bio based low-density materials. Cellulose (London), 5, 2599-2613
Open this publication in new window or tab >>Water-stable cellulose fiber foam with antimicrobial properties for bio based low-density materials
2016 (English)In: Cellulose (London), ISSN 0969-0239, E-ISSN 1572-882X, Vol. 5, p. 2599-2613Article in journal (Refereed) Published
Abstract [en]

New bio-based packaging materials are highly interesting for replacing conventional fossil based products for a more sustainable society. Water-stable cellulose fiber foams have been produced in a simple one-batch foam-forming process with drying under ambient conditions. The cellulose fiber foams have a low density (33–66 kg/m3) and can inhibit microbial growth; two highly valuable features for insulating packaging materials, especially in combination with stability in water. Cationic chitosan and/or polyvinylamine have been added during the foam-forming process to give the foams water-stability and antimicrobial properties. The structural and mechanical properties of the cellulose fiber foams have been studied and the antimicrobial properties have been evaluated with respect to both Escherichia coli, a common model bacteria and Aspergillus brasiliensis, a sporulating mold. The cellulose foams containing chitosan had both good water-stability and good antibacterial and antifungal properties, while the foams containing PVAm did disintegrate in water and did not inhibit fungal growth when nutrients were added to the foam, showing that it is possible to produce a bio-based foam material with the desired characters. This can be an interesting low-density packaging material for protection from both mechanical and microbial damage without using any toxic compounds.

Place, publisher, year, edition, pages
Springer, 2016
Keywords
Antibacterial, Antifungal, Cellulosic, Chitosan, Citric acid, Insulation, Packaging, Polyvinylamine, Wet-stable
National Category
Paper, Pulp and Fiber Technology
Research subject
Fibre and Polymer Science
Identifiers
urn:nbn:se:kth:diva-238841 (URN)10.1007/s10570-018-1738-y (DOI)
Note

QC 20181112

Available from: 2018-11-12 Created: 2018-11-12 Last updated: 2018-11-12Bibliographically approved
Ottenhall, A., Illergård, J. & Ek, M.Water purification using functionalized cellulose with non-leaching bacteria adsorbing properties.
Open this publication in new window or tab >>Water purification using functionalized cellulose with non-leaching bacteria adsorbing properties
(English)Manuscript (preprint) (Other academic)
Abstract [en]

Portable purification systems are easy ways to obtain clean drinking water when there is no large-scale water treatment available. In this study, the potential to purify water using bacteria adsorbing cellulose functionalized with polyelectrolytes, according to the Layer-by-Layer method, is investigated. The adsorbed polyelectrolytes create a positive charge on the cellulose surface that physically attracts and bonds with bacteria. Three types of cellulose material have been modified and tested for the bacterial removal capacity in water. The time, material-water ratio and bacterial concentration dependence, as well as the bacterial removal capacity in water from natural sources, have been evaluated. Freely dispersed bacteria adsorbing cellulose can remove greater than 99.9% of Escherichia coli from non-turbid water, with the most notable reduction occurring within the first hour. For turbid water, a filtering approach using modified cellulose fibers is desirable. This bacteria adsorbing cellulose does not leach any biocides, and it is an environmentally sustainable and cheap option for disposable water purification devices.

Keywords
Contact-active material, emergency treatment, polyelectrolyte multilayer
National Category
Paper, Pulp and Fiber Technology
Research subject
Chemistry
Identifiers
urn:nbn:se:kth:diva-204508 (URN)
Note

QC 20170328

Available from: 2017-03-27 Created: 2017-03-27 Last updated: 2017-03-28Bibliographically approved
Organisations
Identifiers
ORCID iD: ORCID iD iconorcid.org/0000-0002-1656-1465

Search in DiVA

Show all publications