Optical spectroscopy methods for the characterization of sol–gel materials

Marques, Ana C.; Rojas-Hernández, Rocío Estefanía; Almeida, Rui M.

doi:10.1007/s10971-021-05592-0

Cited by 5 publications

(3 citation statements)

References 211 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…(i) Transient gelation: Taking the G-quadruplex-based transient gels as an example, proton nuclear magnetic resonance ( 1 H NMR), rheology, powder X-ray diffraction (XRD), small-angle neutron scattering (SANS), and CD spectroscopy have been used to demonstrate the formation of G-quadruplexes in the system and thus the transient formation of the gels. 25,58,[107][108][109][110] (ii) Transient liquefaction of gels: The main characterization technique is rheology. In addition, there are some more structural characterization techniques related to transient liquefaction, which can refer to the related contents of the transient gels.…”

Section: Characterization Techniques For Transiently Regulatable Gelsmentioning

confidence: 99%

“…In addition, there are some more structural characterization techniques related to transient liquefaction, which can refer to the related contents of the transient gels. 63,110 (iii) Transient assembly of macroscopic gels: Taking the previous work of our group as an example, the pH or ionic strength of the systems changed during the assembly and disassembly processes, leading to the changes in the surface charge density of the polyelectrolyte hydrogels, so these systems can be characterized by zeta potential measurements. 28,78 In addition, the tensile test is also an important experiment to quantify the binding strength of the macroscopic assemblies.…”

Section: Characterization Techniques For Transiently Regulatable Gelsmentioning

confidence: 99%

See 1 more Smart Citation

Transient regulation of gel properties by chemical reaction networks

et al. 2023

View full text Add to dashboard Cite

show abstract

Section: Characterization Techniques For Transiently Regulatable Gelsmentioning

confidence: 99%

Section: Characterization Techniques For Transiently Regulatable Gelsmentioning

confidence: 99%

Transient regulation of gel properties by chemical reaction networks

et al. 2023

View full text Add to dashboard Cite

show abstract

“…[30] Various experimental techniques are available to analyze the optical transitions in ZnO, including optical propagation, optical reflection, optical reflectance, calorimetric spectroscopy, spectroscopic ellipsometry and photoluminescence (PL). [25,31] Because of the existence of its green band, ZnO is regarded as a world's most trusted luminescent material and is used in planar displays and also in some screens with short-decay cathode luminescence. [32,33]…”

Section: Optical Properties Of Znomentioning

confidence: 99%

The effect of magnesium doping concentration on the structural and optical properties of zinc oxide nanoparticles

Nazar¹,

Mishal²,

Khalid³

et al. 2022

JOR

View full text Add to dashboard Cite

In this study, the optical and structural properties of Magnesium doped Zinc Oxide (Zn1-xMgxO) nanoparticles (x = 1%, 3%, and 5%) were examined. The synthesis was carried out at 300 oC by using a simple co-precipitation method. The structural samples were used to characterize the synthesized nanoparticles by using Scanning Electron Microscopy (SEM) and X-Ray Diffraction (XRD). Energy Dispersive X-Ray spectroscopy (EDX) was used to determine the chemical composition of the samples. Furthermore, UV-Vis spectroscopy was conducted to study our samples’ optical characteristics. As per XRD analysis, both pure and Mg doped ZnO samples possess wurtzite structure. The particle size was revealed to decrease significantly with Mg concentration, from 36 nm for pure sample to 23.87 nm with 5% Mg. In comparison to ZnO, the XRD pattern of Mg-doped ZnO shows a peak shift towards lower 2θ values. As a result of deformation of crystal structure caused by integrated Mg+2 ions onto Zn+2 sites. SEM images of synthesized samples reveal that the nanoparticles possess sheet, spherical and rod like morphologies for different values of x. The EDX analysis verifies the purity of samples within the detection limits. According to optical absorption spectra obtained from UV-Visible spectroscopy in the 200nm to 1000nm range affirmed that as Mg concentration increased, the band gap increased from 3.37 eV for pure sample to 3.74 eV with 5% Mg. The UV-Visible spectra of pure ZnO and Mg-doped ZnO samples also exhibit distinct peaks in the UV region at 335 nm, 311 nm, 310.6 nm, and 310 nm. Across the spectra of pure and Mg-doped ZnO samples, the UV peak is attributed to free exciton transitions, whereas, in the spectra of Mg-doped ZnO UV absorbance peak in the visible region is attributed to the radiative transitions of electrons captured at oxygen vacant sites with holes trapped at singly ionized oxygen vacancies.

show abstract