uu.seUppsala University Publications
Change search
Link to record
Permanent link

Direct link
BETA
Song, Man
Publications (7 of 7) Show all publications
Song, M., Tahershamsi, L., Zhao, J., Zhang, Z.-B. & Grennberg, H. (2018). Efficient Gelation of Graphene Oxide Aqueous Dispersion Induced by Sonication-Promoted Leuckart Reaction. Paper presented at 2018/10/22. ChemNanoMat, 0(0)
Open this publication in new window or tab >>Efficient Gelation of Graphene Oxide Aqueous Dispersion Induced by Sonication-Promoted Leuckart Reaction
Show others...
2018 (English)In: ChemNanoMat, ISSN 2199-692X, Vol. 0, no 0Article in journal (Refereed) Published
Abstract [en]

Abstract Graphene oxide (GO) undergoes a rapid gelation process in the presence of ammonium hydroxide and formic acid at room temperature which is promoted by ultrasonication. Infrared and X-ray photoelectron spectroscopy proved partial reduction of GO and nitrogen incorporation, resulting from sonication-promoted Leuckart reactions at GO carbonyl groups. The amine groups produced via Leuckart reactions undergo further reactions that result in salt bridges with carboxylic groups and covalent cross-links, both of which contribute to the stabilization of the resulting hydrogel. The resultant GO hydrogel exhibits enhanced thermal stability.

Place, publisher, year, edition, pages
Wiley-Blackwell, 2018
Keywords
Gelation, graphene oxide, hydrogels, Leuckart reaction, ultrasonication
National Category
Materials Engineering
Identifiers
urn:nbn:se:uu:diva-363972 (URN)10.1002/cnma.201800286 (DOI)
Conference
2018/10/22
Funder
Swedish Foundation for Strategic Research , SE13-0061Swedish Research Council, No. 621-2014-5596
Available from: 2018-10-22 Created: 2018-10-22 Last updated: 2018-10-22
Zhao, J., Song, M., Wen, C., Majee, S., Yang, D., Wu, B., . . . Zhang, Z.-B. (2018). Microstructure-tunable highly conductive graphene-metal composites achieved by inkjet printing and low temperature annealing. Journal of Micromechanics and Microengineering, 28(3), Article ID 035006.
Open this publication in new window or tab >>Microstructure-tunable highly conductive graphene-metal composites achieved by inkjet printing and low temperature annealing
Show others...
2018 (English)In: Journal of Micromechanics and Microengineering, ISSN 0960-1317, E-ISSN 1361-6439, Vol. 28, no 3, article id 035006Article in journal (Refereed) Published
Abstract [en]

We present a method for fabricating highly conductive graphene-silver composite films with a tunable microstructure achieved by means of an inkjet printing process and low temperature annealing. This is implemented by starting from an aqueous ink formulation using a reactive silver solution mixed with graphene nanoplatelets (GNPs), followed by inkjet printing deposition and annealing at 100 degrees C for silver formation. Due to the hydrophilic surfaces and the aid of a polymer stabilizer in an aqueous solution, the GNPs are uniformly covered with a silver layer. Simply by adjusting the content of GNPs in the inks, highly conductive GNP/Ag composites (> 106 S m(-1)), with their microstructure changed from a large-area porous network to a compact film, is formed. In addition, the printed composite films show superior quality on a variety of unconventional substrates compared to its counterpart without GNPs. The availability of composite films paves the way to the metallization in different printed devices, e.g. interconnects in printed circuits and electrodes in energy storage devices.

Place, publisher, year, edition, pages
IOP PUBLISHING LTD, 2018
Keywords
graphene, composite, inkjet printing
National Category
Materials Engineering
Identifiers
urn:nbn:se:uu:diva-345709 (URN)10.1088/1361-6439/aaa450 (DOI)000423867400001 ()
Funder
Swedish Foundation for Strategic Research , Dnr SE13-0061Swedish Research Council, 621-2014-5596
Available from: 2018-03-14 Created: 2018-03-14 Last updated: 2018-03-28Bibliographically approved
Song, M., Zhao, J., Grennberg, H. & Zhang, Z.-B. (2018). Screen Printed Conductive Composites with Reduced Graphene Oxide and Silver. In: 2018 IMAPS Nordic Conference on Microelectronics Packaging (NordPac): . Paper presented at 2018 IMAPS Nordic Conference on Microelectronics Packaging (NordPac) (pp. 35-39).
Open this publication in new window or tab >>Screen Printed Conductive Composites with Reduced Graphene Oxide and Silver
2018 (English)In: 2018 IMAPS Nordic Conference on Microelectronics Packaging (NordPac), 2018, p. 35-39Conference paper, Published paper (Refereed)
Abstract [en]

This work provides a method to fabricate conductive composites by screen printing of aqueous hybrid inks with graphene oxide (GO) and silver acetate as silver source. The formulation of the aqueous hybrid inks is realized by mixing highly concentrated GO solution and reactive silver solution, which readily results in a formation of viscous pastes. Composite films with four-probe structure were fabricated by means of blade coating, followed by annealing at 160 °C in air and subsequently at 600 °C in Ar/H 2 . While the reactive silver solution without GO can be completely reduced when annealed at 90 °C in air, resulting in elemental Ag films with resistivity close to the bulk value, no reduction occurs in the hybrid inks under the same annealing condition. Silver nanoparticles are formed from the hybrid inks at 160 °C and discretely distributed on the reduced GOs (rGOs), which shows a retardation effect of GO on the reduction of silver. Further annealing at 600 °C in Ar/H 2 leads to partial restoration of sp 2 lattice in the rGOs. The resistivity of the composite films increases as the silver content is increased, which is interpreted by using a percolation model with rGO networks.

Keywords
annealing, coatings, electrical conductivity, electrical resistivity, graphene compounds, mixing, nanocomposites, nanofabrication, nanoparticles, percolation, reduction (chemical), silver, thin films, aqueous hybrid inks, silver acetate, reactive silver solution, silver nanoparticles, reduced graphene oxide, screen printed conductive composites, viscous pastes, four-probe structure, blade coating, retardation effect, percolation model, temperature 160.0 degC, temperature 600.0 degC, temperature 90.0 degC, CO-Ag, Ink, Films, Conductivity, Printing, Graphene, graphene oxide, conductive composite, screen printing
National Category
Materials Engineering
Identifiers
urn:nbn:se:uu:diva-363974 (URN)10.23919/NORDPAC.2018.8423856 (DOI)
Conference
2018 IMAPS Nordic Conference on Microelectronics Packaging (NordPac)
Funder
Swedish Research Council, No. 621-2014-5596Swedish Foundation for Strategic Research , Dnr SE13-0061
Available from: 2018-10-22 Created: 2018-10-22 Last updated: 2018-10-22
Miao, F., Majee, S., Song, M., Zhao, J., Zhang, S. & Zhang, Z.-B. (2016). Inkjet printing of electrochemically-exfoliated graphene nano-platelets. Synthetic metals, 220, 318-322
Open this publication in new window or tab >>Inkjet printing of electrochemically-exfoliated graphene nano-platelets
Show others...
2016 (English)In: Synthetic metals, ISSN 0379-6779, E-ISSN 1879-3290, Vol. 220, p. 318-322Article in journal (Refereed) Published
Abstract [en]

In this study, we report on a facile method of inkjet printing of graphene nano-platelets (GNPs). The GNPs are exfoliated from graphite by means of an electrochemical process in an inorganic salt based electrolyte. The electrochemically exfoliated GNPs with oxygen-bearing functional groups exhibit spectroscopic features similar to those of reduced graphene oxides. As a result, ink formulation with such GNPs for inkjet printing readily accomplishes without using stabilizer and various conductive objects are easily fabricated on different substrates by inkjet printing. The as-printed films of the electrochemically exfoliated GNPs deliver an electrical conductivity of 44 S/m, a typical value for as-printed pristine GNP films in the literature. A simple thermal treatment results in an improved DC conductivity by two orders of magnitude to ~2.5 × 103 S/m.

Place, publisher, year, edition, pages
Elsevier, 2016
Keywords
Graphene; Electrochemical process; Inkjet printing
National Category
Other Materials Engineering
Identifiers
urn:nbn:se:uu:diva-298103 (URN)10.1016/j.synthmet.2016.06.029 (DOI)000383811300040 ()
Funder
Swedish Foundation for Strategic Research , Dnr SE13-0061Swedish Research Council, 621-2014-5596
Available from: 2016-06-29 Created: 2016-06-29 Last updated: 2017-11-28Bibliographically approved
Majee, S., Song, M., Zhang, S.-L. & Zhang, Z.-B. (2016). Scalable inkjet printing of shear-exfoliated graphene transparent conductive films. Carbon, 102, 51-57
Open this publication in new window or tab >>Scalable inkjet printing of shear-exfoliated graphene transparent conductive films
2016 (English)In: Carbon, ISSN 0008-6223, E-ISSN 1873-3891, Vol. 102, p. 51-57Article in journal (Refereed) Published
Abstract [en]

In this study, we demonstrate scalable and efficient inkjet printing of graphene flexible transparent conducting films (TCFs). The highly concentrated and stable graphene ink (3.2 mg/mL) that is dominated by 4-layer graphene flakes is achieved by means of shear exfoliation process. The printed graphene TCFs with DC conductivity of ∼4 × 104 S/m (sheet resistance 260 Ω/□ coupled with optical transparency of 86%) without intentional doping are readily obtained. Excellent flexibility and air stability of the printed graphene TCFs allow their potential applications in different flexible opto-electronics devices. Systematic investigation of the inkjet printing of graphene and the annealing effect on the graphene TCFs is presented.

Keywords
Graphene, Inkjet printing, Transparent conductive films
National Category
Condensed Matter Physics Engineering and Technology
Identifiers
urn:nbn:se:uu:diva-276479 (URN)10.1016/j.carbon.2016.02.013 (DOI)000372808200006 ()
Funder
Swedish Foundation for Strategic Research , Dnr SE13-0061Swedish Research Council, 621-2014-5596
Available from: 2016-02-14 Created: 2016-02-14 Last updated: 2017-11-30Bibliographically approved
Ahlberg, P., Hinnemo, M., Song, M., Gao, X., Olsson, J., Zhang, S.-L. & Zhang, Z.-B. (2015). A two-in-one process for reliable graphene transistors processed with photolithography. Applied Physics Letters, 107(20), Article ID 203104.
Open this publication in new window or tab >>A two-in-one process for reliable graphene transistors processed with photolithography
Show others...
2015 (English)In: Applied Physics Letters, ISSN 0003-6951, E-ISSN 1077-3118, Vol. 107, no 20, article id 203104Article in journal (Refereed) Published
Abstract [en]

Research on graphene field-effect transistors (GFETs) has mainly relied on devices fabricated using electron-beam lithography for pattern generation, a method that has known problems with polymer contaminants. GFETs fabricated via photo-lithography suffer even worse from other chemical contaminations, which may lead to strong unintentional doping of the graphene. In this letter, we report on a scalable fabrication process for reliable GFETs based on ordinary photo-lithography by eliminating the aforementioned issues. The key to making this GFET processing compatible with silicon technology lies in a two-in-one process where a gate dielectric is deposited by means of atomic layer deposition. During this deposition step, contaminants, likely unintentionally introduced during the graphene transfer and patterning, are effectively removed. The resulting GFETs exhibit current-voltage characteristics representative to that of intrinsic non-doped graphene. Fundamental aspects pertaining to the surface engineering employed in this work are investigated in the light of chemical analysis in combination with electrical characterization.

National Category
Physical Sciences Engineering and Technology
Identifiers
urn:nbn:se:uu:diva-269191 (URN)10.1063/1.4935985 (DOI)000365688700049 ()
Funder
Knut and Alice Wallenberg Foundation, 2011.0113, 2011.0082Swedish Foundation for Strategic Research , SE13-0061Swedish Research Council, 621-2014-5591
Available from: 2015-12-14 Created: 2015-12-14 Last updated: 2017-12-01Bibliographically approved
Majee, S., Song, M., Zhang, S. L. & Zhang, Z. (2015). Production of transparent and conductive stable graphene ink for inkjet printing method. In: : . Paper presented at EMRS Fall Meeting 2015.
Open this publication in new window or tab >>Production of transparent and conductive stable graphene ink for inkjet printing method
2015 (English)Conference paper, Oral presentation with published abstract (Refereed)
Abstract [en]

Electrical interconnections are one of the main challenges in the printed electronics, to connect different functional units of an electronic device. With the progressive advancement of large area and low cost printed electronic devices on polymeric and paper substrates, the requirement for reliable interconnections with lower power consumption fabricated at low temperature is necessary. The conventional copper-based interconnections suffer severe problems in terms of cost efficiency when they are processed with photolithography technique. To replace the conventional metallic interconnections we have proposed printed interconnects with graphene inks. This is mainly motivated by two reasons. First, printing is a low-cost patterning approach which is performed at ordinary ambient condition. Printing of graphene proved to be a promising since it combines the attractive features of graphene and the cost effective printing methods (ink-jet printing, nozzle printing, spray printing) which enable additive patterning, direct writing, scalability to large area manufacturing. In order to facilitate the inkjet printing process, the graphene solution needs to be highly stable, uniform and should contain smaller sheet sizes (~ 1 micro meter) because of the limitation of the nozzle size of inkjet printing machine. In this work we have proposed a cost-effective approach for large-scale production of printable stable graphene suspension by liquid-phase shear exfoliation of graphite for printed electronics application. The process is scalable and requires shorter processing time compared to the other existing exfoliation methods. Graphene sheets have been exfoliated from graphite flakes in a solvent, cyclohexanone with ethyl cellulose as stabilizer. The graphene based solution prepared after several optimizations leads to a stable ink for more than six months without any sedimentation. The initial studies confirmed the production of graphene films with average sheet thickness of 10 to 20 nm and without any agglomeration with sheet sizes less than 1 micro meter. The rheological properties, such as, viscosity, of the produced graphene ink has been carefully tuned in order for successful inkjet printing process. Highly conductive and transparent (~70 % in the visible region) interconnections have been developed after several inkjet printing steps.

National Category
Other Materials Engineering
Identifiers
urn:nbn:se:uu:diva-260202 (URN)
Conference
EMRS Fall Meeting 2015
Available from: 2015-08-17 Created: 2015-08-17 Last updated: 2016-04-22
Organisations

Search in DiVA

Show all publications