Insight into thermodynamic process and dry preparation of lanthanum fluoride
Tóm tắt
As an important functional material, lanthanum fluoride (denoted as LaF3) shows promising application in infrared thermometry, infrared thermography and fluoride glass optical fiber, etc. Although great process has been obtained in preparing rare earth fluorides such as GdF3, YF3, and NdF3, the thermodynamic process and synthesis of LaF3 remain a challenge. Herein, the thermodynamic process is explored by theoretical calculation and cxs
$$\Delta_{{\text{r}}} H$$
<0,
$$\Delta_{{\text{r}}} G$$
<0,
$$K_{{\text{p}}}$$
>109, indicating that the whole fluorination reaction is an exothermic reaction and can be fully carried out. Moreover, we now report an optimum fluorination process of LaF3. By exploring the effects of reaction temperature, holding time, material layer thickness and HF gas flow on fluorination rate k, the reliability of theoretical calculation has been verified, the best fluorination parameters have been obtained and the fluorination rate can reach more than 97%. This work may shed some light on the large-scale industrial production of high-grade LaF3, and promote its applications in infrared optical field, nuclear medicine and high-energy physics.
Tài liệu tham khảo
Haijuan Cheng XY, Peng Lang, Qunyan Pu, Cai Yi, Li M, Yang W, Bai Y, Zhao J, Wang L. LaF3-ZnS–Ge high-durability MWIR antireflective film on Ge substrate. Infrared Laser Eng. 2019;48(11):117001.
Haijuan Cheng WY, Cai Yi, Xiaohui Y, Li R, Wang K, Zhao J, Wang L. High-performance LEIR antireflective films fabrication on Ge substrate using LaF3 as low refractive index material. Infrared Technol. 2020;42(8):758–62.
Yinnan Feng YH, Liu J, Chen L, Wei J, Li C. Research process of rare earth infrared anti-reflection films. Chin J Rare Metals. 2019;43(12):1346–56.
Li B, Xie P, Su W, Ma X, Luo H, Liu D. Combinatorial synthesis of BaClF-ReF 3 (Re=La, Pr, Er, Sm) layers with graded-index as antireflection coatings in the thermal infrared. Mater Design. 2016;107:302–10.
Cai XY, Wang Y, Li JF, Zhu ZJ, Tu CY. Spectral analyses of Dy3+/Sr2+: LaF3 and Dy3+/Ca2+: LaF3 mixed crystals for laser applications. Spectrochim Acta Part A Mol Biomol Spectrosc. 2020;250:119341.
Lo AYH, Sudarsan V, Sivakumar S, Veggel FV, Schurko RW. Multinuclear solid-state NMR spectroscopy of doped lanthanum fluoride nanoparticles. J Am Chem Soc. 2007;129(15):4687–700.
Semashko VV, Pudovkin MS, Cefalas AC, Zelenikhin PV, Sarantopoulou E. Tiny rare-earth fluoride nanoparticles activate tumour cell growth via electrical polar interactions. Nanoscale Res Lett. 2018. https://doi.org/10.1186/s11671-018-2775-z.
Ewing KJ, Buckner L, Jaganathan J, Ginther R, Aggarwal ID. Preparation of high purity lanthanum compounds for use in fluoride optical fibers - sciencedirect. Mater Res Bull. 1989;24(2):163–8.
Środa M. Effect of LaF3 admixture on thermal stability of borosilicate glasses. J Therm Anal Calorim. 2007;88(1):245–9.
Parshin SG. Metallurgical effect of rare-earth lanthanum fluoride and boride in the composite coating of wires in the arc welding of bainitic-martensitic and austenitic steel. Metals - Open Access Metall J. 2020;10(10):1334.
Massot L, Gibilaro M, Nicaise J, Chamelot P. Electrochemical behaviour of Lanthanum fluoride and Praseodymium fluoride on inert and reactive electrodes in molten LiF–CaF2. J Fluorine Chem. 2021;246:109797.
Siming Pang SY, Li Z, Chen D, Lihai X, Zhao B. Development on molten salt electrolytic methods and technology for preparing rare earth metals and alloys in China. Chin J Rare Metals. 2011;35(3):440–8.
Yi Liu HC, Wei W. Technology of Xeransis fluorination for preparing high purity scandium fluoride. Hunan Nonferrous Metals. 2017;33(1):53–7.
Jianping Wang JH, Ye J. Study on preparation technology of lanthanum fluoride. Henan Chem Ind. 2019;39(02):29–33.
Longping Liu FL, Zhou W, Liu L, Li D. The new exploration of dry preparation of rare earth fluoride. Hunan Nonferrous Metals. 2015;31(4):61–2.
Minlai Li ZL, Zhu Z, Cui D, Peng X, Zhao N, Cui M, Huang X. Hydro-Fluorination synthesis of lanthanum fluoride using lanthanum hydroxide as raw materials. Chin J Rare Metals. 2006;30(3):348–52.
Yajun Wang QL, Suo Q, Hao D, Guo F. Precipitation method and component of rare earth fluoride. Chin Rare Earths. 2000;21(1):14–8.
Zhanzhong Hao BW, Zhang H. Preparation of hypoxia gadolinium fluoride with fixed-bed gas fluorination method. Chin Rare Earths. 2013;34(5):16–21.
Zhanzhong Hao JZ, Wang B, Zhang X. Synthesis of GdF3 from the Gd2O3–NH4HF2 system. Rare Metals. 2007;26(5):482–7.
Zuping Yin JJ, Liu Y. Thermodynamic calculations and experiments for preparation of neodymium fluoride with hydrogen fluoride. Sci Technol Baotou Steel. 2010;36(1):32–5.
Junyong Zhao XL, Dawei Wang, Zuping Yin, Yunyi Liu. Research on neodymium oxide fluorination by fluidized bed. Chem Eng 2010;314–18.
Mukherjee A, Awasthi A, Mishra S, Krishnamurthy N. Studies on fluorination of Y2O3 by NH4HF2. Thermochim Acta. 2011;520(1–2):145–52.
Duan Y, Yu Y, Wang L, Zhao S. Dual-emission LaF3:Tb@DPA-Eu nanoparticles as a ratiometric fluorescence probe for the detection of marbofloxacin. Microchem J. 2021;168:106469.
Yanes AC, Mirabal-Bello P, Del-Castillo J. Enhanced and tuneable green and red emissions in RE3+ doped LaF3 nanocrystals. J Alloys Compd. 2020;856:157183.
Deshmukh P, Deo RK, Ahlawat A, Khan AA, Satapathy S. Spectroscopic investigation of upconversion and downshifting properties LaF3:Tb3+, Yb3+: a dual mode green emitter nanophosphor. J Alloys Compd. 2020;859:157857.
Huang P, Luo P, Zhou B, Wang L, Jiang W. Preparation and luminescence of transparent silica glass-ceramics containing LaF3:Eu3+ nanocrystals. Materials Letters. 2020;271:127764.
Cruz ME, Durán A, Balda R, Fernández J, Mather GC, Castro Y. A new sol–gel route towards Nd3+-doped SiO2–LaF3 glass-ceramics for photonic applications. Mater Adv. 2020;1:3589–96.
Tolstoy VP, Danilov DV, et al. Formation of oriented LaF3 and LaF3:Eu3+ nanocrystals at the gas - Solution interface. J Fluorine Chem. 2017;200:18–23.
Pawlik N, Szpikowska-Sroka B, Goryczka T, Pisarski WA. Studies of sol–gel evolution and distribution of Eu3+ ions in glass-ceramics containing LaF3 nanocrystals depending on initial sols composition. Int J Mol Sci. 2021;22(3):996.
Ansari AA, Parchur AK, Labis JP, Shar MA. Physiochemical characterization of highly biocompatible, and colloidal LaF3:Yb/Er upconversion nanoparticles. Photochem Photobiol Sci. 2021;44:1–14.