Cellulose carbamate derived cellulose thin films: preparation, characterization and blending with cellulose xanthate

Despite being rather old, the Viscose process still is the most important and frequently used technology for the production of regenerated wood based fibers with annual production volumes exceeding 3.5 million tons, mainly for the textile industry.*

However, there are several environmental drawbacks of this technology. For instance, the necessity to use CS2 to form the cellulose precursor material (cellulose xanthate, CX), as well as the development of volatile sulfur containing compounds (e.g. H2S, COS) during the regeneration procedure requires complex recovery technologies, which manifest into higher prices of the final fiber products.*

Another technology that has raised attention in recent years is the Carbacell process. The Carbacell process relies on cellulose carbamate (CC), which is easily obtained by reacting cellulose with urea. CC is soluble in cold alkali and can be subjected to wet spinning processes similar to those in viscose plants.*

In their article: “Cellulose carbamate derived cellulose thin films: preparation, characterization and blending with cellulose xanthate” Michael Weißl, Mathias Andreas Hobisch, Leena Sisko Johansson, Kay Hettrich, Eero Kontturi, Bert Volkert and Stefan Spirk introduce a new system for manufacturing cellulose thin films based on ecofriendly CC. *

Since CC is water soluble, the use of organic solvents is omitted compared to the other often employed cellulose derivative, TMSC. In addition, CC can be synthesized in large scale via environmentally friendly procedures. The regeneration process itself does not require any additional treatment but is induced by increasing the NaOH concentration during the spin-coating via evaporation of the water, as confirmed by IR and XPS spectroscopy.*

Atomic Force Microscopy in tapping mode using a NanoWorld Arrow-NCR AFM probe was employed to gain further information about the surface morphology and structure of the CC films.

Fig. 3 from “Cellulose carbamate derived cellulose thin films: preparation, characterization and blending with cellulose xanthate” by Michael Weißl et al.:
2 × 2 µm2 AFM height (upper row) and phase (lower row) images of CC based thin films after spin coating and rinsing with water; starting with concentrations from 1.0 to 1.5, 2.0 and 2.5 wt%

*Michael Weißl, Mathias Andreas Hobisch, Leena Sisko Johansson, Kay Hettrich, Eero Kontturi, Bert Volkert, Stefan Spirk
Cellulose carbamate derived cellulose thin films: preparation, characterization and blending with cellulose xanthate
Cellulose, August 2019, Volume 26, Issue 12, pp 7399–7410
Doi: https://doi.org/10.1007/s10570-019-02600-z

Please follow this external link to read the full article: https://link.springer.com/article/10.1007%2Fs10570-019-02600-z

Open Access: The paper « Cellulose carbamate derived cellulose thin films: preparation, characterization and blending with cellulose xanthate » by Michael Weißl, Mathias Andreas Hobisch, Leena Sisko Johansson, Kay Hettrich, Eero Kontturi, Bert Volkert and Stefan Spirk is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The images or other third party material in this article are included in the article’s Creative Commons license, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons license and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/.

Electrical conductivity of silver nanoparticle doped carbon nanofibres measured by CS-AFM

Composite carbon nanofibres (CNFs) are highly interesting materials which are usable in a wide array of applications e.g. electrode materials for biosensors, lithium ion batteries, fuel cells and supercapacitors.*

In their paper “Electrical conductivity of silver nanoparticle doped carbon nanofibres measured by CS-AFM” Wael Ali, Valbone Shabani, Matthias Linke, Sezin Sayin, Beate Gebert, Sedakat Altinpinar, Marcus Hildebrandt, Jochen S. Gutmann and Thomas Mayer-Gall present a study on the electrical properties of composite carbon nanofibres (CNFs) using current-sensitive atomic force microscopy (CS-AFM).*

This technique makes it possible to explore the electrical properties of single fibers and hence derive relationships between the structural features and the electrical properties.
NanoWorld AFM probes with conductive PtIr5 coated silicon tips (force constant 2.8 N m−1, length 240 μm, mean width 35 μm and a thickness of 3 μm, and tip height 10–15 μm) Arrow-EFM were used.*

The results presented in the paper show that the composite CNFs have a higher electrical conductivity than the neat CNFs and both the average diameter of the fibers and the electrical conductivity increase with an increasing AgNP content.*

Fig. 8 from “Electrical conductivity of silver nanoparticle doped carbon nanofibres measured by CS-AFM “ by Wael Ali et al.: CS-AFM analysis of CNFs processed from PAN nanofibres electrospun with different concentrations. Images show the friction and current after both stabilisation (a) and carbonisation (b) processes. The applied bias voltage was +0.15 V. The scan area was 5 × 5 μm2 with a scale bar of 1 μm.

Fig. 8 from “Electrical conductivity of silver nanoparticle doped carbon nanofibres measured by CS-AFM “ by Wael Ali et al.: CS-AFM analysis of CNFs processed from PAN nanofibres electrospun with different concentrations. Images show the friction and current after both stabilisation (a) and carbonisation (b) processes. The applied bias voltage was +0.15 V. The scan area was 5 × 5 μm2 with a scale bar of 1 μm.

*Wael Ali, Valbone Shabani, Matthias Linke, Sezin Sayin, Beate Gebert, Sedakat Altinpinar, Marcus Hildebrandt, Jochen S. Gutmann, Thomas Mayer-Gall
Electrical conductivity of silver nanoparticle doped carbon nanofibres measured by CS-AFM
RSC Adv., 2019, 9, 4553-4562
DOI: 10.1039/C8RA04594A

Please follow this external link to the full article: https://pubs.rsc.org/en/content/articlehtml/2019/ra/c8ra04594a

Open Access: The article “Electrical conductivity of silver nanoparticle doped carbon nanofibres measured by CS-AFM” by Wael Ali, Valbone Shabani, Matthias Linke, Sezin Sayin, Beate Gebert, Sedakat Altinpinar, Marcus Hildebrandt, Jochen S. Gutmann and Thomas Mayer-Gall is licensed under a Creative Commons Attribution 3.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. To view a copy of this license, visit https://creativecommons.org/licenses/by/3.0/.

Piezoelectricity of green carp scales

Today is Children’s Day in Japan and many mulit-colored carp-shaped koinobori streamers will flutter in the wind. So it is the perfect day to share the publication “Piezoelectricity of green carp scales” by Y. Jiang et al. with you. Piezoelectricity takes part in multiple important functions and processes in biomaterials often vital to the survival of organisms. In their publication , “Piezoelectricity of green carp scales” Y. Jiang et al. investigate the piezoelectric properties of fish scales of green carp by directly examining their morphology at nanometer levels. From the clear distinctions between the composition of the inner and outer surfaces of the scales that could be found, the authors identified the piezoelectricity to originate from the presence of hydroxyapatite which only exists on the surface of the fish scales.*
koinobori - carp streamers on children's day in Matsumoto Japan
koinobori – carp streamers in Matsumoto Japan
These findings reveal a different mechanism of how green carp are sensitive to their surroundings and should be helpful to studies related to the electromechanical properties of marine life and the development of bio-inspired materials. As easily accessible natural polymers, fish scales can be employed as highly sensitive piezoelectric materials in high sensitive and high speed devices as well as be exploited for invasive diagnostics and other biomedical implications.* For the harmonic responses of both 1st order and 2nd order described in this publication, NanoWorld Arrow-CONTPt AFM probes were used.
FIG. 6 from “Piezoelectricity of green carp scales “ by H. Y. Jiang et al.: First and second harmonic responses of (a) domain I and (b) domain IV. The straight line fitting for the amplitude of first harmonic response of (c) domain I and (d) domain IV by applying a series of bias. NanoWorld Arrow-CONTPt AFM probes were used.
FIG. 6 from “Piezoelectricity of green carp scales “ by H. Y. Jiang et al.: First and second harmonic responses of (a) domain I and (b) domain IV. The straight line fitting for the amplitude of first harmonic response of (c) domain I and (d) domain IV by applying a series of bias.
*Y. Jiang, F. Yen, C. W. Huang, R. B. Mei, and L. Chen Piezoelectricity of green carp scales AIP Advances 7, 045215 (2017) DOI: https://doi.org/10.1063/1.4979503 Please follow this external link to access the full article: https://aip.scitation.org/doi/full/10.1063/1.4979503 Open Access The article “Piezoelectricity of green carp scales” by Y. Jiang, F. Yen, C. W. Huang, R. B. Mei and L. Chen is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The images or other third party material in this article are included in the article’s Creative Commons license, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons license and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/.