Johannes Walter

Dr. Johannes Walter

orcid

Research Focus & Metrics

Academic Career Length

16Years (2011-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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25 November 2014 in Journal of the American Chemical Society
Verified
Journal Article
Closed access
VSVolker Strauss
Volker Strauss
JMJohannes T. Margraf
Johannes T. Margraf
CDChristian Dolle
Christian Dolle
BBBenjamin Butz
Benjamin Butz
TNThomas J. Nacken
Thomas J. Nacken
Dirk GuldiDirk Guldi
Dirk Guldi

20 August 2014 in ACS Nano
Verified
Journal Article
Closed access
JWJohannes Walter
Johannes Walter
KLKonrad Löhr
Konrad Löhr
EKEngin Karabudak
Engin Karabudak
WRWieland Reis
Wieland Reis
JMJules Mikhael
Jules Mikhael
Helmut CölfenHelmut Cölfen
Helmut Cölfen

17 November 2015 in Physical Chemistry Chemical Physics
Verified
Journal Article
Closed access
PDF file
WWWenshuo Wang
Wenshuo Wang
CDCornelia Damm
Cornelia Damm
JWJohannes Walter
Johannes Walter
TNThomas J. Nacken
Thomas J. Nacken
WPWolfgang Peukert
Wolfgang Peukert
In this work we performed a detailed investigation of the photostability of bottom-up produced carbon nanodots (CDs) prepared from citric acid and urea by solvothermal synthesis.

23 June 2015 in RSC Advances
Verified
Journal Article
Closed access
PDF file
TNT. J. Nacken
T. J. Nacken
CDC. Damm
C. Damm
JWJohannes Walter
Johannes Walter
ARA. Rüger
A. Rüger
WPWolfgang Peukert
Wolfgang Peukert
A scalable industrial method for graphene and Few-Layer-Graphene (FLG) production by graphite delamination in N-methylpyrrolidone and water–surfactant mixtures using a high pressure homogenizer is presented. This paper is focused on processing conditions and extensive subsequent analysis of the delaminated products by a combination of analytical ultracentrifugation, UV/Vis and statistical Raman spectroscopies including co-localization with atomic force microscopy. In this way quantitative processing-structure–property correlations showing how suspension properties and processing parameters governing yield, quality and lateral dimension of the produced graphene are obtained. It is found that a high pressure homogenizer can be used to obtain sufficiently high concentrated FLG suspensions with low defect concentration.

8 October 2023 in Small
Verified
Journal Article
Open access
ABAndreas Baer
Andreas Baer
SWSimon E. Wawra
Simon E. Wawra
KBKristina Bielmeier
Kristina Bielmeier
MUMaximilian J. Uttinger
Maximilian J. Uttinger
DSDavid M. Smith
David M. Smith
ASAna-Sunčana Smith
Ana-Sunčana Smith
The Stokes–Einstein–Sutherland (SES) equation is at the foundation of statistical physics, relating a particle's diffusion coefficient and size with the fluid viscosity, temperature, and the boundary condition for the particle‐solvent interface. It is assumed that it relies on the separation of scales between the particle and the solvent, hence it is expected to break down for diffusive transport on the molecular scale. This assumption is however challenged by a number of experimental studies showing a remarkably small, if any, violation, while simulations systematically report the opposite. To understand these discrepancies, analytical ultracentrifugation experiments are combined with molecular simulations, both performed at unprecedented accuracies, to study the transport of buckminsterfullerene C60 in toluene at infinite dilution. This system is demonstrated to clearly violate the conditions of slow momentum relaxation. Yet, through a linear response to a constant force, the SES equation can be recovered in the long time limit with no more than 4% uncertainty both in experiments and in simulations. This nonetheless requires partial slip on the particle interface, extracted consistently from all the data. These results, thus, resolve a long‐standing discussion on the validity and limits of the SES equation at the molecular scale.

24 December 2014 in Chemistry of Materials
Verified
Journal Article
Closed access
WLWei Lin
Wei Lin
JWJohannes Walter
Johannes Walter
ABAlexandra Burger
Alexandra Burger
HMHarald Maid
Harald Maid
AHAndreas Hirsch
Andreas Hirsch
DSDoris Segets
Doris Segets