The sol-gel transformation of aqueous solutions of aluminium ions into aluminium (oxy)hydroxides induced by the addition of a 'soft base'-'Tris-buffer' (pK(a)=8.2) has been investigated using monotonous single-batch titrations and a combination of four complimentary techniques for monitoring pH, conductivity, viscosity and ultrasound parameters (velocity and attenuation). The multi-probe monitoring of the formation of aluminium (oxy)hydroxides enabled important stages of the sol-gel transformation process including: the structural conversion of aluminium Keggin-like polynuclear clusters into nanoparticles of aluminium (oxy)hydroxide; the aggregation of primary nuclei of aluminium (oxy)hydroxide into larger particles, and the 'arrested growth' of the aggregates with the formation of the three-dimensional gel network to be followed. The effect of aluminium ion molecular speciation on the sol-gel transformation stages is discussed. The data presented show that ultrasonic spectrometry, although a novel tool for sol-gel studies, is beneficial for the non-invasive monitoring of the latter stages of aluminium (oxy)hydroxide formation and its eventual breakdown in the presence of excess base.
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http://dx.doi.org/10.1016/j.jcis.2008.12.042 | DOI Listing |
Introduction: Dozens of vaccines have been approved or authorized internationally in response to the ongoing SARS-CoV-2 pandemic, covering a range of modalities and routes of delivery. For example, mucosal delivery of vaccines via the intranasal (i.n.
View Article and Find Full Text PDFJ Comp Pathol
December 2024
Departamento de Patología Animal, Universidad de Zaragoza, 50013 Zaragoza, Spain; Instituto Universitario de Investigación Mixto Agroalimentario de Aragón (IA2), Universidad de Zaragoza, 50013 Zaragoza, Spain. Electronic address:
Langmuir
November 2024
State Key Laboratory of Fine Chemicals, Dalian University of Technology, 2 Linggong Road, 116024 Dalian, China.
Aluminum-based adjuvants have been indispensable to vaccine potency. However, their effectiveness is difficult to maintain after freeze-drying, which limits the storage and application of aluminum-adjuvanted vaccines. In this study, the impact of freeze-drying on aluminum oxyhydroxide nanorods (AlOOH NRs) was investigated.
View Article and Find Full Text PDFInt J Biol Macromol
December 2024
Centre for Polymer Science and Technology, Department of Chemistry, University of Calicut, Calicut University P.O., Malappuram, Kerala 673 635, India. Electronic address:
This study explores the eco-friendly synthesis of carboxymethyl chitosan/polyethylene oxide/γ-aluminium oxyhydroxide (CMCS/PEO/γ-AlOOH) nanocomposite films through a sustainable, green preparation method. The CMCS/PEO/γ-AlOOH nanocomposites were characterized through X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM) to analyze their structural and morphological properties. The emergence of distinct peaks of γ-AlOOH in XRD and FTIR spectra indicated the strong interaction between γ-AlOOH and the blend.
View Article and Find Full Text PDFEnviron Sci Technol
November 2024
Physical & Computational Science Directorate, Pacific Northwest National Laboratory, Richland, Washington 99354, United State.
Incorporation of pollutants, e.g., heavy metals, or critical elements, e.
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