Tag: Arrow-UHFAuD

Real-Time Observation of Fibrous Zeolites Reactivity in Contact with Simulated Lung Fluids (SLFs) Obtained by Atomic Force Microscope (AFM)

Inhalation of fibrous erionite particles has been linked to malignant mesothelioma. Accordingly, erionite is considered the most carcinogenic mineral. The reactivity and the nature of erionite biotoxicity has been the subject of intensive research. Despite very close chemical and structural relationships between erionite and offretite, the reactivity of offretite in lung fluids remains unknown.*
In their paper “Real-Time Observation of Fibrous Zeolites Reactivity in Contact with Simulated Lung Fluids (SLFs) Obtained by Atomic Force Microscope (AFM)”, Matteo Giordani, Georgia Cametti, Fulvio Di Lorenzo and Sergey V. Churakov investigate the interaction of erionite and offretite surfaces with simulated lung fluids by means of in situ atomic force microscope (AFM).*

The outcomes presented in the paper mentioned above represent an important step in understanding the complex processes occurring at the surfaces of mineral fibres that could be involved in the toxicological pathway.*

The topography scans were performed in tapping mode with a NanoWorld Arrow-UHFAuD AFM probes under different experimental conditions.
To better discriminate the role of the tip from the actual fluid-surface interaction, additional measurements were performed in air and in water in contact mode using an Al-coated NanoWorld Arrow-CONTR AFM cantilever.

Figure 2 from M. Giordani et al. “Real-Time Observation of Fibrous Zeolites Reactivity in Contact with Simulated Lung Fluids (SLFs) Obtained by Atomic Force Microscope (AFM)”: Atomic force microscope (AFM) images of offretite FF surface, in MilliQ water at 25 °C, at different magnifications: (a) height retrace image of particles of different sizes on surface and related sections (d); (b) amplitude retrace image of particularly clean surface terraces and related section (c).

*Matteo Giordani, Georgia Cametti, Fulvio Di Lorenzo and Sergey V. Churakov
Real-Time Observation of Fibrous Zeolites Reactivity in Contact with Simulated Lung Fluids (SLFs) Obtained by Atomic Force Microscope (AFM)
Minerals 2019, 9(2), 83
DOI: https://doi.org/10.3390/min9020083

Please follow this external link for the full article: https://www.mdpi.com/403600

Open Access: The paper « Real-Time Observation of Fibrous Zeolites Reactivity in Contact with Simulated Lung Fluids (SLFs) Obtained by Atomic Force Microscope (AFM) » by Matteo Giordani, Georgia Cametti, Fulvio Di Lorenzo and Sergey V. Churakov 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/.

In Situ Molecular-Level Observation of Methanol Catalysis at the Water–Graphite Interface

“Methanol occupies a central role in chemical synthesis and is considered an ideal candidate for cleaner fuel storage and transportation. It can be catalyzed from water and volatile organic compounds, such as carbon dioxide, thereby offering an attractive solution for reducing carbon emissions.”*

In “In Situ Molecular-Level Observation of Methanol Catalysis at the Water–Graphite Interface” the authors show that graphite immersed in ultrapure water is able to spontaneously catalyze methanol from volatile organic compounds in ambient conditions. Using single-molecule resolution atomic force microscopy (AFM) in liquid, they directly observe the formation and evolution of methanol–water nanostructures at the surface of graphite.*
The findings described in this article could have a significant impact on the development of organic catalysts and on the function of nanoscale carbon devices

NanoWorld ARROW-UHFAuD AFM probes were used for the Atomic Force Microscopy imaging in liquid.

Figure 1 from “In Situ Molecular-Level Observation of Methanol Catalysis at the Water–Graphite Interface” by W. Foster et al.: High-resolution amplitude modulation AFM imaging of HOPG immersed in initially ultrapure water. (a) A solid-like patch formed by the self-assembly of molecules (dashed white outline) nucleates from an atomic step at the HOPG surface (dashed black line). The molecular self-assembly is observed here in situ as it progressively grows across the HOPG surface over a period of 9 min, with the patch edges moving away from the step. Rowlike structures with a periodicity of 4.30 ± 0.28 nm as visible within the patch. (b) Sub-nanometer imaging of other structures reveals detailed features (0.79 ± 0.08 nm periodicity, red arrows) perpendicular to the main rows (periodicity 2.45 ± 0.08 nm, white arrow). The exact molecular arrangement is not known, but strongly reminiscent of the alternated water–methanol nanoribbons recently reported by our group.(22) The white scale bars are 100 nm in (a) and 1 nm in (b). The purple color scale bar represents a topographic variation of 20 Å in (a) and 1 Å nm in (b). The blue scale bar represents a phase variation of 20° in (a) and 10° in (b). In (a) the time lapse between the first and second frames is 1 min and then 4 min elapses between the subsequent frames. NanoWorld Arrow-UHFAuD AFM probes were used.
Figure 1 from “In Situ Molecular-Level Observation of Methanol Catalysis at the Water–Graphite Interface” by W. Foster et al.: High-resolution amplitude modulation AFM imaging of HOPG immersed in initially ultrapure water. (a) A solid-like patch formed by the self-assembly of molecules (dashed white outline) nucleates from an atomic step at the HOPG surface (dashed black line). The molecular self-assembly is observed here in situ as it progressively grows across the HOPG surface over a period of 9 min, with the patch edges moving away from the step. Rowlike structures with a periodicity of 4.30 ± 0.28 nm as visible within the patch. (b) Sub-nanometer imaging of other structures reveals detailed features (0.79 ± 0.08 nm periodicity, red arrows) perpendicular to the main rows (periodicity 2.45 ± 0.08 nm, white arrow). The exact molecular arrangement is not known, but strongly reminiscent of the alternated water–methanol nanoribbons recently reported by our group.(22) The white scale bars are 100 nm in (a) and 1 nm in (b). The purple color scale bar represents a topographic variation of 20 Å in (a) and 1 Å nm in (b). The blue scale bar represents a phase variation of 20° in (a) and 10° in (b). In (a) the time lapse between the first and second frames is 1 min and then 4 min elapses between the subsequent frames

*William Foster, Juan A. Aguilar, Halim Kusumaatmaja, Kislon Voϊtchovsky
In Situ Molecular-Level Observation of Methanol Catalysis at the Water–Graphite Interface
ACS Appl. Mater. Interfaces, 2018, 10 (40), pp 34265–34271
DOI: 10.1021/acsami.8b12113

Please follow this external link for the full article: https://pubs.acs.org/doi/full/10.1021/acsami.8b12113

Open Access The article “In Situ Molecular-Level Observation of Methanol Catalysis at the Water–Graphite Interface” by William Foster, Juan A. Aguilar, Halim Kusumaatmaja and Kislon Voϊtchovsky 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/.

Visualisation of Xanthan Conformation by Atomic Force Microscopy

For the research for this article a NanoWorld Arrow-UHFAuD AFM probe was used. Click here to view the full publication: Visualisation of xanthan conformation by atomic force microscopy

Fig. 1. Early stage images of xanthan on mica in aqueous buffer. (a) Method 1, drop-deposited, imaged in buffer 1. (b) Method 2, in-situ adsorbed from and imaged in buffer 2. Bottom panels: Line profiles depict the heights of the features beneath the white lines in the images.
Fig. 1.
Early stage images of xanthan on mica in aqueous buffer. (a) Method 1, drop-deposited, imaged in buffer 1. (b) Method 2, in-situ adsorbed from and imaged in buffer 2. Bottom panels: Line profiles depict the heights of the features beneath the white lines in the images.

  • Jonathan Moffat et. al. , Visualisation of xanthan conformation by atomic force microscopy, Carbohydrate Polymers, 148 (2016), pp 380–389

    Abstract

    Direct visual evidence obtained by atomic force microscopy demonstrates that when xanthan is adsorbed from aqueous solution onto the heterogeneously charged substrate mica, its helical conformation is distorted. Following adsorption it requires annealing for several hours to restore its ordered helical state. Once the helix state reforms, the AFM images obtained showed clear resolution of the periodicity with a value of 4.7 nm consistent with the previously predicted models. In addition, the images also reveal evidence that the helix is formed by a double strand, a clarification of an ambiguity of the xanthan ultrastructure that has been outstanding for many years.

    Open Access funded by Biotechnology and Biological Sciences Research Council Under a Creative Commons license