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Hydrothermal recycling of natural and synthetic polymers to functional carbon materials
KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi.
2019 (engelsk)Doktoravhandling, med artikler (Annet vitenskapelig)
Abstract [en]

Utilizing renewable recourses and waste recycling are necessary for reaching a circular resource society. The concept of this thesis was to set up a sustainable recycling route, suitable even for low quality biopolymer and plastic waste for production of functional carbon materials. Carbonaceous materials were prepared by mild hydrothermal carbonizations of cellulose and polypropylene (PP) under acidic conditions. The carbonization of cellulose resulted mainly in micro-/nanometer sized carbon spheres (CS) with polar functionalities. After carbonization of PP, products were found in solid and liquid phase. Completely carbonized solid carbons products were obtained from PP at 250 °C after 60 min. The liquid products from the same process displayed aromatics and exhibited fluorescence properties. In addition, new carbon materials were prepared by acid, base and thermal treatments of the carbonized products at low temperatures. Thermally resistant carbon products and antibacterial CS towards both Staphylococcus aureus and Pseudomonas aeruginosa were demonstrated as possible applications for these products. The minimum inhibitory concentrations of CS were 200-400 µg mL-1 depending on the bacteria strain and reached after only 3 h. Furthermore, nanometer sized carbon nanodots with high oxygenation degree and fluorescence properties were derived together with carbon flakes (CF) from the carbonized products. The CF with flat and micrometer sized morphology and polar groups were utilized for coating of cationized cellulose filters, applied as adsorbents and then subsequently as surfaces for SALDI-MS analysis of environmental contaminants. This work contributes with new routes to and applications for functional carbon materials.

sted, utgiver, år, opplag, sider
KTH Royal Institute of Technology, 2019. , s. 75
Serie
TRITA-CBH-FOU ; 2019:18
HSV kategori
Identifikatorer
URN: urn:nbn:se:kth:diva-248720ISBN: 978-91-7873-156-5 (tryckt)OAI: oai:DiVA.org:kth-248720DiVA, id: diva2:1303759
Disputas
2019-05-09, sal F3, Lindstedtsvägen 26, Stockholm, 10:00 (engelsk)
Opponent
Veileder
Merknad

QC 20190411

Tilgjengelig fra: 2019-04-11 Laget: 2019-04-10 Sist oppdatert: 2019-04-23bibliografisk kontrollert
Delarbeid
1. Valorization of cellulose and waste paper to graphene oxide quantum dots
Åpne denne publikasjonen i ny fane eller vindu >>Valorization of cellulose and waste paper to graphene oxide quantum dots
2015 (engelsk)Inngår i: RSC Advances, ISSN 2046-2069, E-ISSN 2046-2069, Vol. 5, nr 34, s. 26550-26558Artikkel i tidsskrift (Fagfellevurdert) Published
Abstract [en]

Biobased graphene oxide quantum dots (GOQD) were derived from cellulose via carbon nanospheres (CN) as intermediate products. Solid CN were synthesized from cellulose through microwave-assisted hydrothermal degradation of alpha-cellulose with H2SO4 as a catalyst at 160 degrees C. The obtained CN were further utilized for the synthesis of GOQD by a two-step reaction including 30 minutes of sonication followed by heating at 90 degrees C under O-rich acidic conditions (HNO3). This process broke down the 3D CN to 2D GOQD. The size of the synthesized GOQD was controlled by the heating time, reaching a dot diameter of 3.3 nm and 1.2 nm after 30 and 60 minutes of heating, respectively. The synthesis process and products were characterized by multiple analytical techniques including FTIR, TGA, SEM, TEM, XPS, XRD, BET, DLS and AFM. Interesting optical properties in aqueous solutions were demonstrated by UV/Vis and fluorescence spectroscopy. Finally we demonstrated that corresponding GOQD can be synthesized from waste paper. This production route thus uses renewable and cheap starting materials and relatively mild synthesis procedures leads to instant nanometric production of 2D dots. In addition it enables recycling of low quality waste to value-added products.

HSV kategori
Identifikatorer
urn:nbn:se:kth:diva-165246 (URN)10.1039/c5ra01805f (DOI)000351556800015 ()2-s2.0-84925262617 (Scopus ID)
Merknad

QC 20150504

Tilgjengelig fra: 2015-05-04 Laget: 2015-04-24 Sist oppdatert: 2019-04-10bibliografisk kontrollert
2. Microwave Assisted Hydrothermal Carbonization and Solid State Postmodification of Carbonized Polypropylene
Åpne denne publikasjonen i ny fane eller vindu >>Microwave Assisted Hydrothermal Carbonization and Solid State Postmodification of Carbonized Polypropylene
2018 (engelsk)Inngår i: ACS SUSTAINABLE CHEMISTRY & ENGINEERING, ISSN 2168-0485, Vol. 6, nr 8, s. 11105-11114Artikkel i tidsskrift (Fagfellevurdert) Published
Abstract [en]

Functional carbon materials produced through a hydrothermal treatment of waste products have gained interest. Particularly, the method is considered more facile and green compared to conventional decomposition methods. Here, we demonstrated an upcycling of polypropylene (PP) waste to carbon materials by a microwave assisted hydro thermal treatment. The solid product obtained from the hydrothermal treatment was analyzed by multiple techniques to reveal the structure and the influence of processing conditions on PP degradation and hydrothermal carbonization. Chemical analyses showed the presence of carbonaceous material independent of acid amount (20 and 30 mL), temperature (210 and 250 degrees C), and time (20-80 min). A complete transformation of PP content to amorphous carbon required 60 min at 250 degrees C. The mass yield of the solid product decreased as a function of harsher processing conditions. At the same time, thermogravimetric analysis illustrated products with increasing thermal stability and a larger amount of remaining residue at 600 degrees C. The solid products consisted of irregular fragments and sheet-like structures. A solid state microwave process in air atmosphere was performed on a product with incomplete carbonization. The modification resulted in a decreased C/O ratio, and TGA analysis in nitrogen showed high thermal stability and degree of carbonization as indicated by the remaining residue of 86.4% at 600 degrees C. The new insights provided on the hydrothermal carbonization, and postmodification in air atmosphere, can catalyze effective handling of plastic waste by enabling transformation of low quality waste into functional carbon materials.

sted, utgiver, år, opplag, sider
AMER CHEMICAL SOC, 2018
Emneord
Plastic waste, Polypropylene, Microwave, Hydrothermal, Hydrochar, Carbonization
HSV kategori
Identifikatorer
urn:nbn:se:kth:diva-234193 (URN)10.1021/acssuschemeng.8b02580 (DOI)000441475500170 ()2-s2.0-85049957721 (Scopus ID)
Merknad

QC 20181001

Tilgjengelig fra: 2018-10-01 Laget: 2018-10-01 Sist oppdatert: 2019-04-10bibliografisk kontrollert
3. Importance of Surface Functionalities for Antibacterial Properties of Carbon Spheres
Åpne denne publikasjonen i ny fane eller vindu >>Importance of Surface Functionalities for Antibacterial Properties of Carbon Spheres
Vise andre…
2019 (engelsk)Inngår i: Advanced Sustainable Systems, ISSN 2366-7486Artikkel i tidsskrift (Fagfellevurdert) Published
Abstract [en]

Carbon spheres (CS) are interesting materials for antibacterial applications. Herein, CS are produced by a green process utilizing microwave-assisted hydrothermal treatment of cellulose. The CS are then postmodified in acidic and basic solutions to evaluate the influence of different functionalities on antibacterial properties. CS contain OH/COOH, C Symbol of the Klingon Empire C, and C Symbol of the Klingon Empire O functionalities, while O-CS produced by acid treatment of CS have additional COOH, and NH/NH2 groups, resulting in carbon spheres with negatively and positively charged groups in dispersion. Treatment with base (Na-CS) removes low molecular weight species with oxygen and results in carbon spheres with the highest C/O ratio. CS, O-CS, and Na-CS have nonporous morphology and are in micro/nanometer sizes, although, smaller sized spheres, hollow spheres, and fragments are also attained in the case of O-CS. O-CS show antibacterial activity toward both Gram-positive Staphylococcus aureus (S. aureus) and Gram-negative Pseudomonas aeruginosa (P. aeruginosa). The minimum inhibitory concentration is 200 and 400 mu g mL(-1) for S. aureus and P. aeruginosa, respectively, and is achieved only after 3 h of incubation. Neither CS nor Na-CS exhibit antibacterial activity. The antibacterial activity is suggested to originate from electrostatic interactions between O-CS and the bacteria.

Emneord
antibacterial; carbon spheres; carbonization; electrostatic interactions; microwaves; surface functionality
HSV kategori
Identifikatorer
urn:nbn:se:kth:diva-248712 (URN)10.1002/adsu.201800148 (DOI)000465001800001 ()
Merknad

QC 20190514

Tilgjengelig fra: 2019-04-09 Laget: 2019-04-09 Sist oppdatert: 2019-05-14bibliografisk kontrollert
4. Carbon flake coated cellulose filters as dual function devices for rapid environmental contaminant detection
Åpne denne publikasjonen i ny fane eller vindu >>Carbon flake coated cellulose filters as dual function devices for rapid environmental contaminant detection
(engelsk)Manuskript (preprint) (Annet vitenskapelig)
HSV kategori
Identifikatorer
urn:nbn:se:kth:diva-249229 (URN)
Merknad

QC 20190411

Tilgjengelig fra: 2019-04-11 Laget: 2019-04-11 Sist oppdatert: 2019-04-11bibliografisk kontrollert

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