Preparation of phosphor coated with a polymer by emulsion polymerization and its application in low‐density polyethylene

Abstract

The long-afterglow phosphor SrAl 2 O 4 : Eu 21 , Dy 31 is liable to hydrolyze in water with deterioration of its luminescent properties. In this study, in situ emulsion polymerization was first used to prepare phosphor coated with poly(methyl methacrylate-co-butyl acrylate) [P(MMA-co-BA)] to improve water resistance. Fourier transform infrared spectra suggested that the polymer attached to the phosphor by chemical bonding. Observation by scanning electron microscopy (SEM) showed that a polymer layer formed on the surface of the phosphor. The resistance to water of the phosphor coated with the polymer layer was much better than that of the uncoated phosphor because the transparent polymer layer could suppress its hydrolysis process. Low-density polyethylene (LDPE) plastics, doped with long-afterglow phosphors, were manufactured with an extrusion technique. Through coating with P(MMA-co-BA), the compatibility of phosphor with the LDPE matrix was improved, as determined by SEM. The luminous LDPE plastics blended with the phosphor coated with polymer showed long and strong phosphorescence with little loss of persistence phosphorescence compared to the uncoated phosphor. The LDPE plastics still retained their mechanical properties through doping with 3% (mass fraction) of the phosphors.

Sunlight‐activated long persistent luminescent polyurethane incorporated with amino‐functionalized SrAl2O4:Eu2+,Dy3+ phosphor

“…Figure presents the FTIR spectra of KH550, SrAl 2 O 4 :Eu 2+ ,Dy 3+ and Amino‐SrAl 2 O 4 :Eu 2+ ,Dy 3+ . For SrAl 2 O 4 :Eu 2+ ,Dy 3+ , the absorption peaks between 3300 and 3500 cm −1 belong to the stretching vibration of OH, and other absorption bands below 1000 cm −1 should be attributed to the stretching vibration mode of the SrAl 2 O 4 structure . After modification, the absorption peak at 1582 cm −1 corresponds to the bending vibration of NH, and the absorption peaks between 3300 and 3500 cm −1 still appear due to the introduced NH 2 groups derived from KH550.…”

Waterproof Alkyl Phosphate Coated Fluoride Phosphors for Optoelectronic Materials

“…[6] Metal oxide shells,s uch as SiO 2 , TiO 2 ,S nO 2 ,A l 2 O 3 ,Y 2 O 3 ,a nd ZnO,a re excellent moistureresistant coatings for phosphors. [6,13] Organophosphate (OP,a lkyl phosphate) materials have numerous industrial applications;for example, they are used as fire retardants,b attery electrolytes,h ardeners for film and photo materials,and as lubricants in engines operating at extremely high temperatures. [6,13] Organophosphate (OP,a lkyl phosphate) materials have numerous industrial applications;for example, they are used as fire retardants,b attery electrolytes,h ardeners for film and photo materials,and as lubricants in engines operating at extremely high temperatures.…”

Feasible preparation of red‐phosphor K2SiF6:Mn4+coated with SiO2 for white light emitting diodes application

“…[6][7][8][9][10] But the organic layers are not stable at high temperature. [11] The oxide metals tend to decrease the external quantum yield of phosphors. [12] Super-hydrophobicmetal-organic materials are studied to improve the waterproof property of fluoride red-phosphors without much decrease in luminescence intensity.…”