Waterproof Light‐Emitting Metal Halide Perovskite–Polymer Composite Microparticles Prepared via Microfluidic Device

Abstract

CH 3 NH 3 PbBr 3 (MAPbBr 3 ) MHP-NPs can be synthesized by reprecipitation of an MAPbBr 3 solution and subsequent stabilization of the produced MAPbBr 3 NPs with ligands. [5] Huang et al. reported that monodispersed MAPbBr 3 MHP-NPs with tunable sizes can be synthesized by introducing an emulsifier such as tert-butanol in the reprecipitation method. [6] Zhang et al. synthesized bright MAPbX 3 (X = Cl, Br, and I) MHP-NPs by the ligand-assisted reprecipitation (LARP) method using n-octylamine and oleic acid co-ligands. [7] Gonzalez-Carrero et al. reported that MAPbBr 3 MHP-NPs without oleic acid long-alkyl ligands could be synthesized by adjusting the molar ratio between the total ammonium salts and PbBr 2 and the octylammonium bromide/MABr/1octadecene molar ratio. [8] Recently, Kim et al. reported that bright MAPbBr 3 MHP-NPs beyond quantum sizes can be synthesized by the reprecipitation method using n-hexylamine and oleic acid co-ligands. [9] Very recently, Park et al. reported that postprocessable MAPbX 3 MHP-NPs can be prepared by the modified LARP method using a reduced amount of N,Ndimethylformamide (DMF) and co-ligands of n-hexylamine and oleic acid. [10] Although a wealth of studies on the synthesis of organic/ inorganic hybrid MHP-NPs have been performed in batch reactor systems, the stability of MHP-NPs must be improved to commercialize practical applications because they have intrinsically poor stability against moisture due to their ionic crystal structure. Therefore, they should be passivated or encapsulated by moisture tolerance materials such as metal oxides and polymers. [11][12][13][14][15][16][17] MHP-NPs encapsulated by polymers can remain flexible due to the flexible polymer matrix, and consequently, they have great potential in diverse applications.So far, MHP-NPs encapsulated by polymers have been synthesized by two separate batch reactions, which are a synthesis process of MHP-NPs in a batch reactor and a separate encapsulation process of the produced MHP-NPs in the batch reactor. [18][19][20][21][22] Hence, it remains challenging to develop a continuous process unifying the two independent synthetic processes. Herein, we investigate a one-step microfluidic synthesis, which enables in situ production of MHP-NPs by LARP and encapsulation of MHP-NPs in cross-linked polymer microspheres by UV curing. The MHP-polymer composite microparticles show enhanced air and moisture stability because they were produced with highly cross-linked hydrophobic polymer. Waterproof light-emitting perovskite-polymer composite microparticles are synthesized by a continuous one-step microfluidic reactor, which enables in situ production of metal halide perovskite nanoparticles (MHP-NPs) by the ligand-assisted reprecipitation process (LARP) and the encapsulation of MHP-NPs by UV cross-linking polymerization in the microfluidic channel. Successful encapsulation of MHP-NPs in polymer microparticles is attributed to the co-dispersion of an LARP solution and UV polymerizable solution in an aqueous continuous phase within ...

Stability Enhancements on Methylammonium Lead‐Based Perovskite Nanoparticles: the Smart Use of Host Matrices

“…All these parameters will affect the amount and diffusion of the precursors within the host cavities (that act as nanoreactors), which at the end will have a correlation with the final morphology of the perovskites formed. Thus, the encapsulation of the nanocrystals aims to Swelling-deswelling method > 3 years in water [27] Polystyrene (PS) MAPbBr 3 UV-crosslinking polymerization in microfluidic reactor > 168 days ambient conditions [28] enhance their stability while keeping their highest photoluminescence. Even though the use of host matrices for stabilizing perovskite nanoparticles has tremendous advantages and is one of the best strategies, still some limitations remain unsolved.…”

“…The latest research about scalable production of waterproof light-emitting perovskite polymer microparticles described the use of a continuous microfluidic reactor. [28] This method allowed MAPbBr 3 perovskite nanoparticles preparation by ligand-assisted precipitation and in situ UV induced cross-linking polymerization in the microfluidic channel. As polymer protection, PS was used to provide excellent air and water stability.…”

Green assessment of polymer microparticles production processes: a critical review

“…Furthermore, Sanofi's guide requests its substitution despite being employed in many polymer microparticle production processes. 89,233,236,237 In addition, DMF, known for its hepatotoxicity and reproductive toxicity, 13 has a low volatility with a relatively high boiling point (153 °C), making it non-compatible with solvent evaporation processes. Pfizer's guidelines recommend its substitution by the more volatile acetonitrile (boiling point: 82 °C).…”

Microfluidic Synthesis, Doping Strategy, and Optoelectronic Applications of Nanostructured Halide Perovskite Materials

“…In Figure 1 a–c,e,f, reagent precursor solution is injected into the microchannel. After combination in the channel, different types of nanomaterials can be achieved ( Table 1 ) [ 25 , 26 , 27 , 29 , 31 , 32 , 33 ].…”

“…The microfluidic channel with controllable morphology and configuration could be efficiently designed and achieved, therefore, nanomaterials could be more precisely synthesized in the microfluidic channel. For example, Kim et al reported the in situ reaction of metal halide perovskite nanoparticles by the ligand-assisted reprecipitation process (LARP) and encapsulation by ultraviolet light (UV) cross-linking polymerization, in which the stable, water-resistant light-emitting perovskite–polymer composite microparticles can be synthesized in a continuous one-step microfluidic reactor [ 26 ]. Tuning the reactant concentration and the flow rate in the microreactor, ranging from several nanometers to over one hundred nanometers, hollow spherical silica-based functional materials and the Cs 4 PbBr 6 perovskite microcrystals (MCs) were synthesized by mixing two reactant flows, respectively [ 25 , 37 ].…”