Tag: tapping mode

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/.

Pb2+ Uptake by Magnesite: The Competition between Thermodynamic Driving Force and Reaction Kinetics

When they are in put in contact with carbonate minerals dangerous environmental pollutants such as Pb2+ and Cd2+ are taken up by the solid phase assemblage and can be removed from aqueous solutions.*

As carbonates can be found almost everywhere and are easily exploitable this makes them interesting materials for environmental remediation.*

However, magnesite ( MGS ) is well-known for the slow dissolution and growth kinetics at room temperature conditions in the so-called dolomite problem.*

In their article “Pb2+ Uptake by Magnesite: The Competition between Thermodynamic Driving Force and Reaction Kinetics” Fulvio Di Lorenzo, Tobias Arnold and Sergey V. Churakov use in situ atomic force microscopy (AFM) to investigate the growth of {10.4} magnesite surfaces in the absence and in the presence of Pb2+ as well as the effect of solution ageing.*

In their study the authors attempt to answer the question if and under which circumstances magnesium carbonate could be used in removing Pb from wastewater.*

The experimental results presented in above mentioned article have the object to discuss and evaluate the theoretical possibilities and the practical limitations that must be taken into account for the development of environmental remediation technologies based on magnesite.*

The experiments conducted in this study by  Fulvio Di Lorenzo et al. demonstrate that, although the thermodynamic conditions are encouraging, the transformation reaction between magnesite and cerrusite makes it improbably that it will play a crucial role in the development of remediation processes for PbII pollution.*

The authors of the study conclude that, although the thermodynamic conditions are encouraging, an environmental remediation process based on MGS as the substrate for a solvent-mediated transformation reaction is unlikely to play a crucial part in industrial applications due to the slow kinetics of MGS dissolution. However, the sluggish kinetics of MGS precipitation is favourable for Pb entrapment by the precipitation of carbonate from Mg2+ and Pb2+-bearing solutions, leading to a strong PbII enrichment in the solid phase even in far-from-equilibirum conditions.*

The in situ flow-through Atomic Force Microscopy was performed using Arrow-UHFAuD AFM probes in tapping mode.

Figure 8 from “Pb2+ Uptake by Magnesite: The Competition between Thermodynamic Driving Force and Reaction Kinetics” by Fulvio Di Lorenzo et al: In situ observation of {10.4} surfaces of MGS in contact with acidic solution, pH 4 (HNO3). The images were acquired in tapping mode. The first row corresponds to height channels, while the second row reports the respective amplitude channels. (A) The dissolution at 25 °C is sluggish and it is not possible to detect any dissolution feature. (B) In the same conditions but at higher temperature (60 °C), dissolution features are observed on the {10.4} surfaces of MGS, despite the retrograde solubility. Yellow and blue lines of constant size are used to highlight the evolution of etch pits and step edges, respectively. This evidence demonstrates that the existence of kinetic barriers controls the dissolution of MGS at room temperature conditions. NanoWorld Arrow-UHFAuD AFM probes were used.
Figure 8 from “Pb2+ Uptake by Magnesite: The Competition between Thermodynamic Driving Force and Reaction Kinetics” by Fulvio Di Lorenzo et al:
 In situ observation of {10.4} surfaces of MGS in contact with acidic solution, pH 4 (HNO3). The images were acquired in tapping mode. The first row corresponds to height channels, while the second row reports the respective amplitude channels. (A) The dissolution at 25 °C is sluggish and it is not possible to detect any dissolution feature. (B) In the same conditions but at higher temperature (60 °C), dissolution features are observed on the {10.4} surfaces of MGS, despite the retrograde solubility. Yellow and blue lines of constant size are used to highlight the evolution of etch pits and step edges, respectively. This evidence demonstrates that the existence of kinetic barriers controls the dissolution of MGS at room temperature conditions.

*Fulvio Di Lorenzo, Tobias Arnold, and Sergey V. Churakov
Pb2+ Uptake by Magnesite: The Competition between Thermodynamic Driving Force and Reaction Kinetics
Minerals 2021, 11(4), 415
DOI: https://doi.org/10.3390/min11040415

Please follow this external link to read the full article: https://www.mdpi.com/2075-163X/11/4/415

Open Access : The article “Pb2+ Uptake by Magnesite: The Competition between Thermodynamic Driving Force and Reaction Kinetics” by Fulvio Di Lorenzo, Tobias Arnold, 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 https://creativecommons.org/licenses/by/4.0/.

Amphiphilic Poly(dimethylsiloxane-ethylene-propylene oxide)-polyisocyanurate Cross-Linked Block Copolymers in a Membrane Gas Separation

Block copolymers, including multiblock copolymers of an amphiphilic nature, because of their ability to form various supramolecular structures are attracting a lot of research interest these days. The direct influence on the supramolecular organization of block copolymers is a way of controlling both the mechanical and physicochemical properties of polymer materials obtained on this basis. *

In the article “Amphiphilic Poly(dimethylsiloxane-ethylene-propylene oxide)-polyisocyanurate Cross-Linked Block Copolymers in a Membrane Gas Separation” Ilsiya M. Davletbaeva, Ilgiz M. Dzhabbarov, Askhat M. Gumerov, Ilnaz I. Zaripov, Ruslan S. Davletbaev, Artem A. Atlaskin, Tatyana S. Sazanova and Ilya V. Vorotyntsev describe how they investigated Multiblock copolymers obtained based on PPEG, D4 (octamethylcyclotetrasiloxane ) and TDI ( 2,4-toluene diisocyanate ).*

The authors studied the realized polymers as membrane materials for the separation of gas mixtures containing CO2/CH4 and CO2/N2 and went on to show that polymers with a cellular supramolecular structure exhibit lower permeability for CO2 in comparison with polymeric film materials whose supramolecular structure is constructed on the basis of the “core-shell” principle. *

It was shown in the above mentioned article that polymers are promising as silica-based membrane materials for the separation of gas mixtures containing CO2/CH4 and CO2/N2. *

As the polymer material investigated for this article is rather soft NanoWorld Pointprobe® FMR AFM probes with a typical force constant of around 2.8 N/m were used for the analysis by atomic force microscopy of the membrane surface.*

Figure 15 from Ilsiya M. Davletbaeva et al “Amphiphilic Poly(dimethylsiloxane-ethylene-propylene oxide)-polyisocyanurate Cross-Linked Block Copolymers in a Membrane Gas Separation”: AFM Images. (a): [PPEG]:[TDI] = 1:10; (b): [PPEG]:[D4]:[TDI] = 1:15:10; (c): [PPEG]:[D4]:[TDI] = 1:15:10 [ASiP] = 0.2 wt.%, (d): [PPEG]:[D4]:[TDI] = 1:15:10 [ASiP] = 0.4 wt.%. NanoWorld Pointprobe® FMR AFM probes were used.
Figure 15 from Ilsiya M. Davletbaeva et al “Amphiphilic Poly(dimethylsiloxane-ethylene-propylene oxide)-polyisocyanurate Cross-Linked Block Copolymers in a Membrane Gas Separation”:
AFM Images. (a): [PPEG]:[TDI] = 1:10; (b): [PPEG]:[D4]:[TDI] = 1:15:10; (c): [PPEG]:[D4]:[TDI] = 1:15:10 [ASiP] = 0.2 wt.%, (d): [PPEG]:[D4]:[TDI] = 1:15:10 [ASiP] = 0.4 wt.%.

*Ilsiya M. Davletbaeva, Ilgiz M. Dzhabbarov, Askhat M. Gumerov, Ilnaz I. Zaripov, Ruslan S. Davletbaev, Artem A. Atlaskin, Tatyana S. Sazanova, and Ilya V. Vorotyntsev
Amphiphilic Poly(dimethylsiloxane-ethylene-propylene oxide)-polyisocyanurate Cross-Linked Block Copolymers in a Membrane Gas Separation
Membranes 2021, 11(2), 94
DOI: https://doi.org/10.3390/membranes11020094

Please follow this external link to read the full article: https://www.mdpi.com/2077-0375/11/2/94/htm#

Open Access : The article “Amphiphilic Poly(dimethylsiloxane-ethylene-propylene oxide)-polyisocyanurate Cross-Linked Block Copolymers in a Membrane Gas Separation” by Ilsiya M. Davletbaeva, Ilgiz M. Dzhabbarov, Askhat M. Gumerov, Ilnaz I. Zaripov, Ruslan S. Davletbaev, Artem A. Atlaskin, Tatyana S. Sazanova, and Ilya V. Vorotyntsev 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/.