In situ XRF analysis of Cs adsorption by the precipitation bands of Prussian blue analogues formed in agarose gels

Abstract

The measurement of Cs adsorption by the precipitation bands of Mn-based Prussian blue analogues (PBAs), Co-based PBAs, and Prussian blue (PB), which were spontaneously formed in agarose gel, was carried out using in situ X-ray fluorescence (XRF) spectroscopy.

Highly Resolved Mn Kβ Emission: A Potential Probe in Laboratory for Analysis of Ligand Coordination around Mn Atoms in Gels and Solutions

“…4(a) exhibit a rich structure. As also found in previous studies, 25,26,28,30 the peak positions of the Mn and Fe Kα distributions coincided well with one another, suggesting that these peaks could be attributed to the presence of Mn-Fe PBAs. It is worth noting that both ED-XRF distributions fluctuated not only at the periodic band zone (X > 15 mm), but also in the turbid zone (0 < X < 15 mm), suggesting that the Mn-Fe PBA concentration fluctuated significantly over a wide region in agarose gel, including the turbid zone.…”

“…4(a) are basically similar to the results reported in previous studies. [28][29][30] This image confirms that Mn-Fe PBAs form discrete precipitation bands in agarose gel, although their number is minimal, and their bandwidths are broad. In accordance with this observation, the ED-XRF distributions in Fig.…”

“…In order to estimate the distribution of Mn-Fe PBAs precipitates in Gel, energy-dispersive X-ray fluorescence (ED-XRF) intensity distribution of Gel was also measured using an experimental setup, the details of which are provided elsewhere. 28 Briefly, Cu Kα1 X-rays from RU-300, operated at 40 kV and 60 mA, were used as the excitation source and were focused within 0.5 mm in the horizontal direction by an SiO2 (101) Johansson-type crystal monochromator (Saint-Gobain Crystals). Gel was placed vertically with respect to the incident X-ray beam with line-shape on a computer-controlled X-Z stage (the combination of two XA05A-L2 stages).…”

“…9,10,12 Furthermore, the selection of Mn Kβ emission is also justified by the following. Recently, Mn-Fe-based Prussian blue analogs (Mn-Fe PBAs) have been found to show several interesting crystallization/precipitation phenomena in gels, [25][26][27][28][29] and their local structure around Mn atoms (examined by XAFS spectroscopy at SR facilities) has become the subject of intense research interest. [25][26][27]30 Meanwhile, the local structure during the development of Mn-Fe PBA precipitation bands (which can significantly influence the quality of Mn-Fe PBAs finally formed 31 ) has not been explored yet, because the time required for their full development (∼10 days) is too long to continuously monitor their XAFS at SR facilities.…”

Prussian Blue: A Safe Pigment with Zeolitic-Like Activity

“…PB has also been immobilized by means of a linkage of polydopamine (PD) on the surface of nanofibers fabricated by electrospinning of polyacrylonitrile (PAN) [ 31 ], on poly(vinyl alcohol) (PVA) sponge [ 32 , 33 ], caged in a gel of sodium alginate [ 34 ], in the same colloid to develop an intestinal release delivery system [ 35 ], in spongiform adsorbents [ 36 ], bonded to sepiolite (hydrated magnesium silicate) [ 37 ], embedded into a binder matrix [ 38 ], in porous cellulose aerogel [ 39 ] or in microporous carboxymethyl cellulose nanofibrils membranes [ 40 ]. Hayashi et al found that PB/PBA precipitated spontaneously in agarose gels, and these materials were able to adsorb Cs + ions effectively [ 41 ]. Zhang et al prepared a clay-based composite hydrogel containing PBA nanoparticles (potassium copper hexacyanoferrate).…”