Thermal Characterization of Agar Encapsulated in TiO2 Sol?Gel

López, T.; Picquart, M.; Aguirre, G.; Arriola, G.; Freile, Y.; Aguilar, D.H.; Quintana, P.; Alvarado‐Gil, J. J.; Luna, Francisco Miguel Vargas

doi:10.1007/s10765-004-5753-x

Cited by 10 publications

(4 citation statements)

References 17 publications

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“…46,47 Other less intense peaks due to PEDOT were detected at 572 and 995 cm −1 due to oxyethylene ring deformation, at 1105 cm −1 due to C-O-C deformation, at 1252 cm −1 due to C ⊍ -C ⊍ inter-ring stretching, at 1369 cm −1 due C ⊎ -C ⊎ stretching and finally at 1507 and 1562 cm −1 due to asymmetric C ⊍ =C ⊎ stretching. 46,48 Further, a band of Ag was observed at 1105 cm −1 due to C-O-H deformation. 49 The relatively weak bands at approximately 1610 and 1660 cm −1 were assigned as amide I and II bands of PAM.…”

Section: Raman Spectroscopymentioning

confidence: 98%

Tough and flexible conductive triple network hydrogels based on agarose/polyacrylamide/polyvinyl alcohol and poly(3,4‐ethylenedioxythiophene):polystyrene sulfonate

Azar

Dodda

Bělský

et al. 2021

Polymer International

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Herein, we demonstrate a simple and cost-effective way to fabricate conductive triple network hydrogels based on agarose (Ag), polyacrylamide (PAM) and poly(vinyl alcohol) (PVA) with a combination of physical-chemical crosslinked networks. The conductivity was generated by doping poly (3,4-ethylenedioxythiophene):polystyrene sulfonate (PEDOT:PSS) into the triple network matrix of Ag-PAM-PVA. All hydrogels were homogeneous in the swollen state and incorporation of PEDOT:PSS did not influence the morphology significantly on a microscale, (light microscopy and cryogenic low-vacuum SEM). On the nanoscale, small-angle X-ray scattering showed some differences between hydrogels with/without PEDOT:PSS and also between double/triple networks. The tensile and compressive properties were enhanced at a lower concentration of PEDOT:PSS, with a maximum tensile strength of 0.47 MPa, at an elongation of 119%. Fortunately, all hydrogels have shown conductivity in the range of 0.3−1.5 mS cm −1 which is comparable with the conductivity of skin tissues and hence they can be conveniently optimized for use in biosensors or other devices related to skin/internal tissues.

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Section: Raman Spectroscopymentioning

confidence: 98%

Tough and flexible conductive triple network hydrogels based on agarose/polyacrylamide/polyvinyl alcohol and poly(3,4‐ethylenedioxythiophene):polystyrene sulfonate

Azar

Dodda

Bělský

et al. 2021

Polymer International

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“…52 A PL spectrum of agarose peaks at about 690 nm (650-740 nm band). 53 Vanishing PL and weak IR absorption enables a good RS/PL contrast for the IR Raman measurement (Figure 5) highlighting a complex structure dominated by the modes typical for agarose (polysaccharide mix): characteristic strong stretching vibrations ν (CH 2 ) within a 2900-3000 cm À1 Stokes band, as well as glucan-related vibrations within 850-990 cm À1 bands with the strong ν(C-O-C) and δ (CCH) modes [54][55][56] of various polysaccharides. A UV excitation does not return Raman features despite the significant UV absorption, and a VIS excitation reveals the worst RS/PL contrast when compared with the NIR-IR lasers.…”

Section: Agar (Ag)mentioning

confidence: 99%

Comparative Raman spectroscopy of astrobiology relevant bio‐samples and planetary surface analogs under UV–VIS–IR excitation

Hanke,

Böttger,

Pohl

et al. 2023

J Raman Spectroscopy

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We investigated the potential of a laser selection in the broad optical range, from ultraviolet through visible to infrared (excitation wavelengths of 325, 532, 785, and 1064 nm) for combined analysis of Earth‐relevant extremophiles (Xanthoria elegans, Buellia frigida, and green alga of Circinaria gyrosa), carbohydrate molecules, as well as Mars and Moon surface regolith simulants as analog mineral mixtures (P‐MRS, S‐MRS, LRS, and JSC‐1). We show that the optimization of the laser photon energy provides (for at least one of the chosen excitation wavelengths) high‐end quality Raman spectra for each examined sample. In most cases, the infrared spectral range is advanced for biological samples, while an excitation in the visible and ultraviolet spectral range is often favorable or at least sufficient for accurate identification/resolution of mineral phases under the illuminated laser spot on the planetary surface simulants. Ultraviolet excitation does not always deliver significant contrast of the Raman Stokes responses to the induced photoluminescence in the studied biomolecules. Most prominent features in the Raman spectra of the biological samples are assigned to their specific pigments, also considered as biomolecular signatures of the extremophiles. The critical issue of specific advantages and limitations of each particular excitation source implies study for gaining scientific return from Raman spectroscopy for exobiological prospecting, for instance, the best trade between a single or dual excitation wavelength(s) for both biological and geological spectral data.

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“…[34] The band at about 1635 cm −1 is assigned to the stretching mode of -C═O and also the absorption band of H 2 O. [35] The peaks between 880 and 1150 cm −1 are typical vibrations of the 3,6-anhydro-galactose networks. [34] The difference spectra after the exposure of the agar film to m-SBF are shown in Figure 5.…”

Section: Atr-ftir Spectroscopy Of Electrolyte Uptake In Hydrogel Filmsmentioning

confidence: 99%

Influence of hydrogel coatings on corrosion and fatigue of iron in simulated body fluid

Huang

Voigt

Wackenrohr

et al. 2022

Materials & Corrosion

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Surface corrosion and fatigue studies of pure iron were performed in a modified simulated body fluid (m-SBF) electrolyte with and without applied agar films as a typical hydrogel film. The electrochemical corrosion rates were analysed using electrochemical impedance spectroscopy. The morphology and surface chemical composition of the samples after exposure were analysed using X-ray photoelectron spectroscopy and Raman microscopy. The swelling process of the agar film was measured by in situ fourier-transform infrared spectroscopy in attenuated total reflection. The combination of the electrochemical and interface analytical approaches allowed for the estimation of the influence of an applied agar film on the corrosion processes. Moreover, the studies clearly reveal a correlation between the surface corrosion process and the fatigue life of the iron samples in m-SBF.

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Thermal Characterization of Agar Encapsulated in TiO2 Sol?Gel

Cited by 10 publications

References 17 publications

Tough and flexible conductive triple network hydrogels based on agarose/polyacrylamide/polyvinyl alcohol and poly(3,4‐ethylenedioxythiophene):polystyrene sulfonate

Tough and flexible conductive triple network hydrogels based on agarose/polyacrylamide/polyvinyl alcohol and poly(3,4‐ethylenedioxythiophene):polystyrene sulfonate

Comparative Raman spectroscopy of astrobiology relevant bio‐samples and planetary surface analogs under UV–VIS–IR excitation

Influence of hydrogel coatings on corrosion and fatigue of iron in simulated body fluid

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