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Jafari, Mohammad JavadORCID iD iconorcid.org/0000-0003-3899-4891
Alternative names
Publications (10 of 11) Show all publications
Patra, H. K., Azharuddin, M., Islam, M. M., Papapavlou, G., Deb, S., Osterrieth, J., . . . Slater, N. K. H. (2019). Rational Nanotoolbox with Theranostic Potential for Medicated Pro-Regenerative Corneal Implants. Advanced Functional Materials, Article ID 1903760.
Open this publication in new window or tab >>Rational Nanotoolbox with Theranostic Potential for Medicated Pro-Regenerative Corneal Implants
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2019 (English)In: Advanced Functional Materials, ISSN 1616-301X, E-ISSN 1616-3028, article id 1903760Article in journal (Refereed) Epub ahead of print
Abstract [en]

Cornea diseases are a leading cause of blindness and the disease burden is exacerbated by the increasing shortage around the world for cadaveric donor corneas. Despite the advances in the field of regenerative medicine, successful transplantation of laboratory‐made artificial corneas is not fully realized in clinical practice. The causes of failure of such artificial corneal implants are multifactorial and include latent infections from viruses and other microbes, enzyme overexpression, implant degradation, extrusion or delayed epithelial regeneration. Therefore, there is an urgent unmet need for developing customized corneal implants to suit the host environment and counter the effects of inflammation or infection, which are able to track early signs of implant failure in situ. This work reports a nanotoolbox comprising tools for protection from infection, promotion of regeneration, and noninvasive monitoring of the in situ corneal environment. These nanosystems can be incorporated within pro‐regenerative biosynthetic implants, transforming them into theranostic devices, which are able to respond to biological changes following implantation.

Place, publisher, year, edition, pages
John Wiley & Sons, 2019
Keywords
herpes simplex virus type 1 (HSV-1), magnetic resonance imaging (MRI), premedicated cornea implants, pro-regeneration, theranostics
National Category
Microbiology in the medical area
Identifiers
urn:nbn:se:liu:diva-159097 (URN)10.1002/adfm.201903760 (DOI)000476281800001 ()2-s2.0-85069940064 (Scopus ID)
Note

Funding agencies: EU H2020 Marie Sklodowska-Curie Individual Fellowship [706694]; MIIC Strategic Postdoc Grant; MIIC Seed Grant at Linkoping University (LiU), Sweden

Available from: 2019-07-24 Created: 2019-07-24 Last updated: 2019-08-23Bibliographically approved
Kaushik, P. D., Aziz, A., Siddiqui, A. M., Greczynski, G., Jafari, M. J., Lakshmi, G. B., . . . Yazdi, G. (2018). Modifications in structural, optical and electrical properties of epitaxial graphene on SiC due to 100 MeV silver ion irradiation. Materials Science in Semiconductor Processing, 74, 122-128
Open this publication in new window or tab >>Modifications in structural, optical and electrical properties of epitaxial graphene on SiC due to 100 MeV silver ion irradiation
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2018 (English)In: Materials Science in Semiconductor Processing, ISSN 1369-8001, E-ISSN 1873-4081, Vol. 74, p. 122-128Article in journal (Refereed) Published
Abstract [en]

Epitaxial graphene (EG) on silicon carbide (SiC) is a combination of two robust materials that are excellent candidates for post silicon electronics. In this work, we systematically investigate structural changes in SiC substrate as well as graphene on SiC and explore the potential for controlled applications due to 100 MeV silver swift heavy ion (SHI) irradiation. Raman spectroscopy showed fluence dependent decrease in intensity of first and second order modes of SiC, along with decrease in Relative Raman Intensity upon ion irradiation. Similarly, Fourier-transform infrared (FTIR) showed fluence dependent decrease in Si-C bond intensity with presence of C = O, Si-O-Si, Si-Si and C-H bond showing introduction of vacancy, substitutional and sp(3) defects in both graphene and SiC. C1s spectra in XPS shows decrease in C = C graphitic peak and increase in interfacial layer following ion irradiation. Reduction in monolayer coverage of graphene after ion irradiation was observed by Scanning electron microscopy (SEM). Further, UV-Visible spectroscopy showed increase in absorbance of EG on SiC at increasing fluence. I-V characterization showed fluence dependent increase in resistance from 62.9 O in pristine sample to 480.1 Omega in sample irradiated at 6.6 x 10(12) ions/cm(2) fluence. The current study demonstrates how SHI irradiation can be used to tailor optoelectronic applicability of EG on SiC.

Place, publisher, year, edition, pages
Pergamon Press, 2018
Keywords
Ion irradiation; Fluence; Epitaxial graphene; Silicon carbide; Optoelectronic
National Category
Condensed Matter Physics
Identifiers
urn:nbn:se:liu:diva-143601 (URN)10.1016/j.mssp.2017.09.026 (DOI)000415924400018 ()2-s2.0-85032226420 (Scopus ID)
Note

Funding Agencies|Graphene Flagship [CNECT-ICT-604391]; Swedish Research Council [2015-05876]

Available from: 2017-12-13 Created: 2017-12-13 Last updated: 2017-12-22Bibliographically approved
Jafari, M. J. (2017). Application of Vibrational Spectroscopy in Organic Electronics. (Doctoral dissertation). Linköping: Linköping University Electronic Press
Open this publication in new window or tab >>Application of Vibrational Spectroscopy in Organic Electronics
2017 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

The rapid technological developments enforce us to live in an increasingly electronic world, and the revolutionary usage of conjugated polymers in electronics in the late 1970s accelerated these developments, based on the unique characteristics of conjugated polymers, such as low cost, easy processing, mechanical flexibility, large-area application and compatibility with a variety of substrates. Organic electronic devices are commercially available in the form of, for example, solar cells, transistors, and organic light-emitting diode (OLED) displays. Scientists work on electroactive polymers to enhance their chemical, electrical and mechanical properties, to improve parameters such as charge carrier mobility and doping capacity, in order to reach acceptable efficiency and stability to fabricate organic electronic devices. A comprehensive understanding of the changes in chemical structure, in response to external factors such as applied potential and temperature gradients, which can disturb the chemical equilibrium of the constituent materials, and of the conduction mechanisms of the operating devices, can help to enhance the performance of organic electronics devices. Vibrational spectroscopy is a powerful analytical method for in-situ monitoring of such chemical or electrochemical reactions and associated structural changes of conjugated polymers in a working device.

In this thesis, Fourier-transform infrared (FTIR) spectroscopy has been used to study the structural changes in electroactive organic materials, in response to chemical or electrochemical reactions, and to study electrical and thermal conduction mechanisms in different organic electronic devices. FTIR microscopy was used to approach a realistic conduction mechanism by time-resolved chemical imaging of active materials in planar light-emitting electrochemical cells (LECs), investigated as an alternative to organic light emitting diodes (OLEDs). These chemical images are used for in-situ mapping of anion density profiles, polymer doping, and dynamic junction formation in the active layer under an applied bias. Results confirm the electrochemical doping model and help the systematic improvement of function and manufacture of LECs. Mixed ion-electron polymeric conductor materials such as PEDOT-PSS are used as active materials in organic thermoelectric generators (OTEGs), where charge carrier transport through the active layer promotes internal electrochemical reactions under a temperature gradient. FTIR microscopy and FTIR-attenuated total reflection (FTIR-ATR) were used to study thermoelectric and electrical properties of the conducting polymers. Recently, electrochemical supercapacitors have emerged as an alternative to conventional batteries, and polymeric materials are used to design polymer electrodes for renewable energy storage. To understand the charge transfer and structural changes of the polymer during the redox reaction, we have used FTIR-ATR as a tool for the in-situ spectroelectrochemical study of redox states in polypyrrole/lignin composites; we clarified the structural changes in the materials during charging and discharging of the composite. In further work, FTIR-ATR was also used for in-situ spectroelectrochemical studies of PEDOT:Cl, to monitor the effects of dissolved oxygen on PEDOT:Cl films, which are used as electrodes in renewable energy technologies. Further, time-resolved oxygen reduction reactions of PEDOT:Cl have been studied via polarization-modulation infrared reflection-absorption spectroscopy (PM-IRAS) to reveal chemical changes in electrochemically doped PEDOT upon exposure to oxygen.

Taken together, these studies provide an advancement in the use of infrared spectroscopy as a tool to understand electroactive materials under wet conditions, and have provided detailed chemical and electrochemical information of materials and devices under operation, that is not easily accessible with other methods.

Place, publisher, year, edition, pages
Linköping: Linköping University Electronic Press, 2017. p. 61
Series
Linköping Studies in Science and Technology. Dissertations, ISSN 0345-7524 ; 1884
National Category
Atom and Molecular Physics and Optics
Identifiers
urn:nbn:se:liu:diva-142216 (URN)9789176854440 (ISBN)
Public defence
2017-11-17, Planck, F-House, Campus Valla, Linköping, 10:15 (English)
Opponent
Supervisors
Available from: 2017-10-23 Created: 2017-10-23 Last updated: 2017-10-23Bibliographically approved
Parlak, O., Beyazit, S., Jafari, M. J., Tse Sum Bui, B., Haupt, K., Tiwari, A. & Turner, A. (2016). Light-triggered switchable graphene-polymer hybrid bioelectronics. Advanced Materials Interfaces, 3(2), 1500353-1-1500353-7
Open this publication in new window or tab >>Light-triggered switchable graphene-polymer hybrid bioelectronics
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2016 (English)In: Advanced Materials Interfaces, ISSN 2196-7350, Vol. 3, no 2, p. 1500353-1-1500353-7Article in journal (Refereed) Published
Abstract [en]

A light-switchable graphene interface to control and regulate electrobiocatalysis in a nanoconfined space is reported for the first time. The development of switchable and/or tunable interfaces on 2D nanosurfaces endowed with desirable functionalities, and incorporation of these interfaces into remote controlled biodevices, is a rapidly emerging area in bioelectronics.

Place, publisher, year, edition, pages
Wiley-VCH Verlagsgesellschaft, 2016
Keywords
light-switchable electrobiocatalysis;remote controlled biodevices;smart graphene;stimuli-encoded bioelectronics
National Category
Condensed Matter Physics
Identifiers
urn:nbn:se:liu:diva-123676 (URN)10.1002/admi.201500353 (DOI)000370043000002 ()
Projects
VR- 2011-6058357
Funder
Swedish Research Council, VR- 2011-6058357
Note

Fundinmg agencies:  Swedish Research Council [VR-2011-6058357]; European Commission [MCITN-2011-289554]

Available from: 2016-01-07 Created: 2016-01-07 Last updated: 2017-01-11Bibliographically approved
Ullah Khan, Z., Bubnova, O., Jafari, M. J., Brooke, R., Liu, X., Gabrielsson, R., . . . Crispin, X. (2015). Acido-basic control of the thermoelectric properties of poly(3,4-ethylenedioxythiophene)tosylate (PEDOT-Tos) thin films. Journal of Materials Chemistry C, 3, 10616-10623
Open this publication in new window or tab >>Acido-basic control of the thermoelectric properties of poly(3,4-ethylenedioxythiophene)tosylate (PEDOT-Tos) thin films
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2015 (English)In: Journal of Materials Chemistry C, ISSN 2050-7526, E-ISSN 2050-7534, Vol. 3, p. 10616-10623Article in journal (Refereed) Published
Abstract [en]

PEDOT-Tos is one of the conducting polymers that displays the most promising thermoelectric properties. Until now, it has been utterly difficult to control all the synthesis parameters and the morphology governing the thermoelectric properties. To improve our understanding of this material, we study the variation in the thermoelectric properties by a simple acido-basic treatment. The emphasis of this study is to elucidate the chemical changes induced by acid (HCl) or base (NaOH) treatment in PEDOT-Tos thin films using various spectroscopic and structural techniques. We could identify changes in the nanoscale morphology due to anion exchange between tosylate and Cl- or OH-. But, we identified that changing the pH leads to a tuning of the oxidation level of the polymer, which can explain the changes in thermoelectric properties. Hence, a simple acid-base treatment allows finding the optimum for the power factor in PEDOT-Tos thin films.

Place, publisher, year, edition, pages
Royal Society of Chemistry, 2015
National Category
Polymer Chemistry Textile, Rubber and Polymeric Materials
Identifiers
urn:nbn:se:liu:diva-121977 (URN)10.1039/C5TC01952D (DOI)000363251600035 ()
Note

Funding agencies: European Research Council (ERC) [307596]

Available from: 2015-10-14 Created: 2015-10-14 Last updated: 2018-08-20Bibliographically approved
Golabi, M., Jafari, M. J., Jager, E., Turner, A. & Ederth, T. (2015). ATR-FTIR: a simple and rapid tool for bacterial resistance detection. In: Conference on Advanced Vibrational Spectroscopy - ICAVS, Vienna, Austria, 12- 17 July 2015.: . Paper presented at Conference on Advanced Vibrational Spectroscopy - ICAVS, Vienna, Austria, 12- 17 July 2015..
Open this publication in new window or tab >>ATR-FTIR: a simple and rapid tool for bacterial resistance detection
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2015 (Swedish)In: Conference on Advanced Vibrational Spectroscopy - ICAVS, Vienna, Austria, 12- 17 July 2015., 2015Conference paper, Poster (with or without abstract) (Refereed)
National Category
Biological Sciences
Identifiers
urn:nbn:se:liu:diva-118105 (URN)
Conference
Conference on Advanced Vibrational Spectroscopy - ICAVS, Vienna, Austria, 12- 17 July 2015.
Available from: 2015-05-21 Created: 2015-05-21 Last updated: 2017-01-11
Ouyang, L., Musumeci, C., Jafari, M. J., Ederth, T. & Inganäs, O. (2015). Imaging the Phase Separation Between PEDOT and Polyelectrolytes During Processing of Highly Conductive PEDOT:PSS Films. ACS Applied Materials and Interfaces, 7(35), 19764-19773
Open this publication in new window or tab >>Imaging the Phase Separation Between PEDOT and Polyelectrolytes During Processing of Highly Conductive PEDOT:PSS Films
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2015 (English)In: ACS Applied Materials and Interfaces, ISSN 1944-8244, E-ISSN 1944-8252, Vol. 7, no 35, p. 19764-19773Article in journal (Refereed) Published
Abstract [en]

Treating PEDOT:PSS (Clevios) with certain additives, such as ethylene glycol (EG), dimethyl sulfoxide (DMSO) and sorbitol, has been shown to increase the conductivity of this material from roughly 1 to nearly 1000 S/cm. Using a slow drying method, we show that the additive induced a separation between free PSS and reorganized PEDOT:PSS complexes in the highly conductive PEDOT:PSS films. Additives (DMSO, DEG, and PEG 400) were included in PEDOT:PSS aqueous dispersions at large volume fractions. The mixtures were slowly dried under room conditions. During drying, the evaporation of water resulted in an additive-rich solvent mixture from which the reorganized PEDOT:PSS complexes aggregated " into a dense film while free PSS remained in the solution. Upon complete drying, PSS formed a transparent rim film around the conducting PEDOT film. The chemical compositions of the two phases were studied using an infrared microscope. This removal of PSS resulted in more compact packing of PEDOT molecules, as confirmed by X-ray diffraction measurements. X-ray photoelectron spectroscopy and atomic force microscope measurements suggested the enrichment of PEDOT on the film surface after PSS separation. Through a simple drying process in an additive-containing dispersion, the conductivity of PEDOT films increased from 0.1 to 200-400 S/cm. Through this method, we confirmed the existence of two phases in additive-treated and highly conductive PEDOT:PSS films. The proper separation between PSS and PEDOT will be of relevance in designing strategies to process high-performance plastic electrodes.

Place, publisher, year, edition, pages
AMER CHEMICAL SOC, 2015
Keywords
PEDOT:PSS; solvent treatment; additives; conductivity enhancement; organic electronics
National Category
Materials Chemistry Inorganic Chemistry
Identifiers
urn:nbn:se:liu:diva-121897 (URN)10.1021/acsami.5b05439 (DOI)000361252400030 ()26290062 (PubMedID)
Note

Funding Agencies|Swedish Strategic Research Foundation (SSF) through the project SiOS; Knut and Alice Wallenberg Foundation

Available from: 2015-10-13 Created: 2015-10-12 Last updated: 2017-12-01
Ajjan, F., Javad Jafari, M., Rebis, T., Ederth, T. & Inganäs, O. (2015). Spectroelectrochemical investigation of redox states in a polypyrrole/lignin composite electrode material. Journal of Materials Chemistry A, 3(24), 12927-12937
Open this publication in new window or tab >>Spectroelectrochemical investigation of redox states in a polypyrrole/lignin composite electrode material
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2015 (English)In: Journal of Materials Chemistry A, ISSN 2050-7488, Vol. 3, no 24, p. 12927-12937Article in journal (Refereed) Published
Abstract [en]

We report spectroelectrochemical studies to investigate the charge storage mechanism of composite polypyrrole/lignin electrodes. Renewable bioorganic electrode materials were produced by electropolymerization of pyrrole in the presence of a water-soluble lignin derivative acting as a dopant. The resulting composite exhibited enhanced charge storage abilities due to a lignin-based faradaic process, which was expressed after repeated electrochemical redox of the material. The in situ FTIR spectroelectrochemistry results show the formation of quinone groups, and reversible oxidation-reduction of these groups during charge-discharge experiments in the electrode materials. The most significant IR bands include carbonyl absorption near 1705 cm(-1), which is attributed to the creation of quinone moieties during oxidation, and absorption at 1045 cm(-1) which is due to hydroquinone moieties.

Place, publisher, year, edition, pages
ROYAL SOC CHEMISTRY, 2015
National Category
Materials Chemistry
Identifiers
urn:nbn:se:liu:diva-120069 (URN)10.1039/c5ta00788g (DOI)000356022800044 ()
Note

Funding Agencies|Knut and Alice Wallenberg foundation; Marie Curie network Renaissance; Swedish Government Strategic Research Area in Materials Science on Functional Materials at Linkoping University [2009-00971]

Available from: 2015-07-06 Created: 2015-07-06 Last updated: 2017-12-04
Tang, Z., Tress, W., Bao, Q., Jafari, M. J., Bergqvist, J., Ederth, T., . . . Inganäs, O. (2014). Improving Cathodes with a Polymer Interlayer in Reversed Organic Solar Cells. Advanced Energy Materials, 4(15), Article ID 1400643.
Open this publication in new window or tab >>Improving Cathodes with a Polymer Interlayer in Reversed Organic Solar Cells
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2014 (English)In: Advanced Energy Materials, ISSN 1614-6832, Vol. 4, no 15, article id 1400643Article in journal (Refereed) Published
Abstract [en]

The effects of cathode modification by a conjugated polymer interlayer PFPA1 on the performance of reversed organic solar cells (substrate/cathode/active layer/transparent anode) based on different active material systems and different substrate electrodes are systematically investigated. A reduction of the work function irrespective of the substrate cathode used is observed upon the deposition of the PFPA1 interlayer, which is further related to an improved built-in electric field and open-circuit voltage. The amphiphilic character of the PFPA1 interlayer alters the surface energy of the substrate cathode, leading to the formation of a better active layer morphology aiding efficient exciton dissociation and photocurrent extraction in the modified solar cells. Hence, internal quantum efficiency is found to be significantly higher than that of their unmodified counterparts, while optically, the modified and unmodified solar cells are identical. Moreover, the deep highest occupied molecular orbital (HOMO) of the PFPA1 interlayer improves the selectivity for all investigated substrate cathodes, thus enhancing the fill factor.

Place, publisher, year, edition, pages
Wiley-VCH Verlagsgesellschaft, 2014
Keywords
organic solar cells; polymer solar cells; interlayer modification; interfaces; selectivity
National Category
Physical Sciences Chemical Sciences
Identifiers
urn:nbn:se:liu:diva-112636 (URN)10.1002/aenm.201400643 (DOI)000344368500014 ()
Note

Funding Agencies|KAW; Science Council (VR); Swedish Energy Agency; Knut and Alice Wallenberg Foundation KAW through the project Power Papers; Wallenberg Scholar grant

Available from: 2014-12-08 Created: 2014-12-05 Last updated: 2017-01-11Bibliographically approved
Tang, Z., Tress, W., Bao, Q., Jafari, M. J., Bergqvist, J., Ederth, T., . . . Inganäs, O. (2014). Universal modification of poor cathodes into good ones by a polymer interlayer for high performance reversed organic solar cells.
Open this publication in new window or tab >>Universal modification of poor cathodes into good ones by a polymer interlayer for high performance reversed organic solar cells
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2014 (English)Manuscript (preprint) (Other academic)
Abstract [en]

In organic bulk-heterojunction solar cells, energy losses at the active layer/electrode interface are often observed. Modification of these interfaces with organic interlayers optimizes charge carrier injection and extraction and thus improves device performance. In this work, the effects of cathode modification by a conjugated polymer interlayer PFPA1 on the performance of reversed organic solar cells (substrate/cathode/active layer/transparent anode) based on different active material systems and different substrate electrodes are systematically investigated. A reduction of the work function irrespective of the substrate cathode used is observed upon the deposition of the PFPA1 interlayer; further related to an improved built-in electric field and open-circuit voltage. The amphiphilic character of the PFPA1 interlayer alters the surface energy of the substrate cathode, leading to the formation of a better active layer morphology aiding efficient exciton dissociation and photocurrent extraction in the modified solar cells. Hence, internal quantum efficiency is found significantly higher than that of their unmodified counterparts, while optically, the modified and unmodified solar cells are identical. Moreover, the deep HOMO of the PFPA1 interlayer improves the selectivity for all investigated substrate cathodes, thus enhancing the fill factor. We demonstrate a possibility of improving photovoltaic performance of reversed solar cells via a simple and universal interface modification and provide the basic guidelines for development and characterization of interface materials for organic solar cells in general.

National Category
Natural Sciences
Identifiers
urn:nbn:se:liu:diva-103928 (URN)
Available from: 2014-02-03 Created: 2014-02-03 Last updated: 2018-09-01Bibliographically approved
Organisations
Identifiers
ORCID iD: ORCID iD iconorcid.org/0000-0003-3899-4891

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