Tag: afm tips

Flexible Polyurethane Foams Modified with Novel Coconut Monoglycerides-Based Polyester Polyols

The products of the polyurethane (PU) industry such as foams, coatings and adhesives are numerous and can be found in many areas of everyday life. *

Polyols are an essential component in the production of polyurethane. Nowadays they mostly come from petroleum products. *

In view of potential risk factors such as the running out of fossil fuels, supply chain issues, environmental concerns and economic risks it is important to develop alternatives as substitutes and supplements to the existing petroleum derived polyols. *

Vegetable oils can be used to manufacture biobased polyols and various oils such as linseed oil, rapeseed oil, canola oil, grapeseed oil, corn oil, rice bran oil, palm oil, olive oil, castor oil and soybean oil have already been used to make polyols for different purposes.*

Most of the polyols derived from vegetable oils that are already commercially available are made from soybean and castor oil and are mainly used for rigid PU foam applications. *

So far biobased materials for flexible polyurethane foams (FPUFs) have not been studied as much as their rigid counterpart. This is because, due to their chemical composition, there are limits to how much biobased materials can be used in the flexible foam without having an undesired effect on the foam’s mechanical properties. *

Coconut oil is not often used to manufacture flexible foam because the coconut oil’s high level of saturation makes it less compatible with many common methods of creating polyols, as the widely used polyol-forming processes mostly rely on the unsaturation of vegetable oil for functionalization.

To make coconut monoglycerides (CMG) or other plant-based oils usable for polyol-forming processes they need to fulfil the same structural requirements as the fossil-based products. *

In the article “Flexible Polyurethane Foams Modified with Novel Coconut Monoglycerides-Based Polyester Polyols “ Christine Joy M. Omisol, Blessy Joy M. Aguinid, Gerson Y. Abilay, Dan Michael Asequia, Tomas Ralph Tomon, Karyl Xyrra Sabulbero, Daisy Jane Erjeno, Carlo Kurt Osorio, Shashwa Usop, Roberto Malaluan, Gerard Dumancas, Eleazer P. Resurreccion, Alona Lubguban, Glenn Apostol, Henry Siy, Arnold C. Alguno, and Arnold Lubguban describe how they investigated the potential of coconut monoglycerides (CMG) as a polyol raw material specifically for flexible polyurethane foam (FPUF) applications.*

The authors synthesized high-molecular-weight polyester polyols from coconut monoglycerides (CMG), a coproduct of fatty acid production from coconut oil, via polycondensation at different mass ratios of CMG with 1:5 glycerol:phthalic anhydride.*

The resulting CMG-based polyols were shown to work well in making flexible foam. *

Fourier transform infrared (FTIR) spectroscopy and atomic force microscopy (AFM) were used for the foam characterization. *

The modification of the foam formulation increased the monodentate and bidentate urea groups, shown using Fourier transform infrared (FTIR) spectroscopy, that promoted microphase separation in the foam matrix, confirmed using atomic force microscopy (AFM) and differential scanning calorimetry (DSC). *

Atomic force microscopy (AFM) was used to evaluate the hard–soft domains phase separation of the foam. *

The atomic force microscope was operated at a scan rate of 1.0 Hz in non-contact mode using NanoWorld Pointprobe® NCHR Silicon AFM probes for standard tapping mode applications. (typical resonance frequency 320 kHz, typical force constant 42 N/m). *

It could be shown that density of the CMGPOL-modified polyurethane foams (CPFs) decreased, while a significant improvement in their tensile and compressive properties was observed. *

The investigations by Christine Joy M. Omisol et al. resulted in a new sustainable polyol raw material that can be used to modify petroleum-based foam and produce flexible foams with varying properties that can be tailored to meet specific requirements. *

Figure 11 from Christine Joy M. Omisol et al (2024) “Flexible Polyurethane Foams Modified with Novel Coconut Monoglycerides-Based Polyester Polyols”:Atomic force microscopy (AFM) phase images of CMGPOL-modified polyurethane foams (CPF) and control foam measured with a size scan of 3 μm × 3 μm showing soft and hard regions represented by red and yellow colors, respectively. The foam samples in Figure 11 that exhibited a relatively high degree of microphase separation compared with other samples are CPF-8 and CPF-20. These foams appear to have relatively lighter areas of urea-rich regions separated more prominently from the darker, polyol-rich regions. In contrast, the control foam and CPF-16 show more dispersed hard and soft domains. CPF-24 and CPF-12 are at the middle of the scale, displaying light regions but with more dispersion than CPF-8 and CPF-20. These observations from the phase images of the foam samples are in agreement with the monodentate and bidentate urea contents of the samples, wherein the foams that exhibit greater H-bonding also manifest a higher degree of microphase separation. The same results were obtained by Baghban et al. NanoWorld Pointprobe® NCHR standard tapping mode/non-contact mode silicon AFM probes were used for the foam characterizations with atomic force microscopy.
Figure 11 from Christine Joy M. Omisol et al (2024) “Flexible Polyurethane Foams Modified with Novel Coconut Monoglycerides-Based Polyester Polyols”:
Atomic force microscopy (AFM) phase images of CMGPOL-modified polyurethane foams (CPF) and control foam measured with a size scan of 3 μm × 3 μm showing soft and hard regions represented by red and yellow colors, respectively.

*Christine Joy M. Omisol, Blessy Joy M. Aguinid, Gerson Y. Abilay, Dan Michael Asequia, Tomas Ralph Tomon, Karyl Xyrra Sabulbero, Daisy Jane Erjeno, Carlo Kurt Osorio, Shashwa Usop, Roberto Malaluan, Gerard Dumancas, Eleazer P. Resurreccion, Alona Lubguban, Glenn Apostol, Henry Siy, Arnold C. Alguno, and Arnold Lubguban
Flexible Polyurethane Foams Modified with Novel Coconut Monoglycerides-Based Polyester Polyols
ACS Omega 2024, 9, 4, 4497–4512
DOI: https://doi.org/10.1021/acsomega.3c07312

The article “Flexible Polyurethane Foams Modified with Novel Coconut Monoglycerides-Based Polyester Polyols” by Christine Joy M. Omisol, Blessy Joy M. Aguinid, Gerson Y. Abilay, Dan Michael Asequia, Tomas Ralph Tomon, Karyl Xyrra Sabulbero, Daisy Jane Erjeno, Carlo Kurt Osorio, Shashwa Usop, Roberto Malaluan, Gerard Dumancas, Eleazer P. Resurreccion, Alona Lubguban, Glenn Apostol, Henry Siy, Arnold C. Alguno and Arnold Lubguban 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 https://creativecommons.org/licenses/by/4.0/.

Visit us at the EPFL CMi 2024 MicroNanoFabrication Annual Review Meeting next week

Come and visit our booth at the EPFL CMi 𝟮𝟬𝟮𝟰 𝗠𝗶𝗰𝗿𝗼𝗡𝗮𝗻𝗼𝗙𝗮𝗯𝗿𝗶𝗰𝗮𝘁𝗶𝗼𝗻 𝗔𝗻𝗻𝘂𝗮𝗹 𝗥𝗲𝘃𝗶𝗲𝘄 𝗠𝗲𝗲𝘁𝗶𝗻𝗴 at the SwissTech Convention Center in Lausanne/Switzerland next Tuesday May 14, 2024 to learn more about our high-quality AFM probes. We’re looking forward to seeing you.

Graphics showing the NanoWorld exhibtion booth with 24 SEM images showing NanoWorld AFM probes for Atomic Force Microsocpy and and invitatin below to come and visit our booth at the EPFL CMi 𝟮𝟬𝟮𝟰 𝗠𝗶𝗰𝗿𝗼𝗡𝗮𝗻𝗼𝗙𝗮𝗯𝗿𝗶𝗰𝗮𝘁𝗶𝗼𝗻 𝗔𝗻𝗻𝘂𝗮𝗹 𝗥𝗲𝘃𝗶𝗲𝘄 𝗠𝗲𝗲𝘁𝗶𝗻𝗴 at the SwissTech Convention Center in Lausanne next Tuesday May 14, 2024 to learn more about our AFM probes. We’re looking forward to seeing you.
Come and visit us in Lausanne next week. We’re looking forward to hearing for what kind of applications you are using Atomic Force Microscopy and AFM probes.

Correlation between plant cell wall stiffening and root extension arrest phenotype in combined abiotic stress of Fe and Al

The plasticity and growth of plant cell walls (CWs) is still not sufficiently understood on its molecular level. *

Atomic Force Microscopy (AFM) has been shown to be a powerful tool to measure the stiffness of plant tissues. *

In the article “Correlation between plant cell wall stiffening and root extension arrest phenotype in the combined abiotic stress of Fe and Al” Harinderbir Kaur, Jean-Marie Teulon, Christian Godon, Thierry Desnos, Shu-wen W. Chen and Jean-Luc Pellequer describe the use of atomic force microscopy (AFM) to observe elastic responses of the root transition zone of 4-day-old Arabidopsis thaliana wild-type and almt1-mutant seedlings grown under Fe or Al stresses. *

In order to evaluate the relationship between root extension and root cell wall elasticity, the authors used Atomic Force Microscopy to perform vertical indentations on surfaces of living plant roots. *

NanoWorld Pyrex-Nitride silicon-nitride PNP-TR AFM probes with triangular AFM cantilevers were used for the nanoindentation experiments with atomic force microscopy. (PNP-TR AFM cantilever beam 2 (CB2) with a typical force constant of 0.08 N/m and a typical resonant frequency of 17 kHz, typical AFM tip radius 10 nm, macroscopic half cone angles 35°). *

Force-distance (F-D) curves were measured using the Atomic Force Microscope and the PNP-TR AFM tips. *

Because of the heterogeneity of seedling CW surfaces, Harinderbir Kaur et al. used the recently developed trimechanics-3PCS framework for interpreting force-distance curves. The trimechanics-3PCS framework allows the extraction of both stiffness and elasticity along the depth of indentation and permits the investigation of the variation of stiffness with varied depth for biomaterials of heterogeneous elasticity responding to an external force. *

A glass slide with a glued seedling (see Figure 1 cited below) was positioned under the AFM cantilever with the help of an AFM optical camera. Due to the large motorized sample stage of the AFM, the glass slide was adjusted in such a way that the AFM cantilever could be positioned perpendicularly at the longitudinal middle of the glued root. The target working area, the transition zone, was 500 µm away from the root apex, almost twice the length of PNP-TR AFM cantilever. *

As shown in the article the presence of single metal species Fe2+ or Al3+ at 10 μM exerts no noticeable effect on the root growth compared with the control conditions. On the contrary, a mix of both the metal ions produced a strong root-extension arrest concomitant with significant increase of CW stiffness. *

Raising the concentration of either Fe2+or Al3+ to 20 μM, no root-extension arrest was observed; nevertheless, an increase in root stiffness occurred. In the presence of both the metal ions at 10 μM, root-extension arrest was not observed in the almt1 mutant, which substantially abolishes the ability to exude malate. The authors’ results indicate that the combination of Fe2+and Al3+ with exuded malate is crucial for both CW stiffening and root-extension arrest. *

It is shown that the elasticity of plant CW is sensitive and can be used to assess abiotic stresses on plant growth and stiffening. *

However, stiffness increase induced by single Fe2+ or Al3+ is not sufficient for arresting root growth in the described experimental conditions and unexpectedly, the stiffening and the phenotype of seedling roots such as REA are not directly correlated. *

Figure 1 from Harinderbir Kaur et al. 2024 “Correlation between plant cell wall stiffening and root extension arrest phenotype in the combined abiotic stress of Fe and Al”:Principle of nanomechanical measurement of seedling roots with atomic force microscopy. A seedling root (R) is deposited on a microscope slide using silicon glue (N, for Nusil). A fastening band of silicon is seen near the tip of the root (T). The thickness of the fastening band must be thin enough to avoid hindering the AFM support (S), but thick enough to withstand the bending of the root tip. The root is placed under the AFM cantilever (C) as observed by the AFM optical camera. The triangular shaped cantilever (200 µm long) was placed 500 µm away from the root tip in the transition zone where nanoindentation measurements proceeded (as shown). The seedling root and the AFM cantilever are placed within a liquid environment (growth solution, see Supplementary file of the cited article). AFM, atomic force microscopy. NanoWorld Pyrex-Nitride silicon-nitride PNP-TR AFM probes with triangular AFM cantilevers were used for the nanoindentation experiments with atomic force microscopy.
Figure 1 from Harinderbir Kaur et al. 2024 “Correlation between plant cell wall stiffening and root extension arrest phenotype in the combined abiotic stress of Fe and Al”:
Principle of nanomechanical measurement of seedling roots with atomic force microscopy.
A seedling root (R) is deposited on a microscope slide using silicon glue (N, for Nusil). A fastening band of silicon is seen near the tip of the root (T). The thickness of the fastening band must be thin enough to avoid hindering the AFM support (S), but thick enough to withstand the bending of the root tip. The root is placed under the AFM cantilever (C) as observed by the AFM optical camera. The triangular shaped cantilever (200 µm long) was placed 500 µm away from the root tip in the transition zone where nanoindentation measurements proceeded (as shown). The seedling root and the AFM cantilever are placed within a liquid environment (growth solution, see Supplementary file of the cited article). AFM, atomic force microscopy.

*Harinderbir Kaur, Jean‐Marie Teulon, Christian Godon, Thierry Desnos, Shu‐wen W. Chen and Jean‐Luc Pellequer
Correlation between plant cell wall stiffening and root extension arrest phenotype in the combined abiotic stress of Fe and Al
Plant, Cell & Environment 2024; 47:574–584
DOI: https://doi.org/10.1111/pce.14744

The article “Correlation between plant cell wall stiffening and root extension arrest phenotype in the combined abiotic stress of Fe and Al” by Harinderbir Kaur, Jean‐Marie Teulon, Christian Godon, Thierry Desnos, Shu‐wen W. Chen and Jean‐Luc Pellequer 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 https://creativecommons.org/licenses/by/4.0/.