Functional Application Of Layered Rare-Earth Hydroxide

In this dissertation,RE(hfa)3(H2O)3 was inserted into the interlayer of Y/Eu binary LRH under proper conditions,and the structure characteristics of swollen LRH,the efficient exfoliation of LRH nanosheets,along with the thermosensitive photoluminescence and functional application,were studied in detail.Detailed characterization of the samples were achieved by techniques of XRD,FE-SEM,HR-TEM,STEM,SAED and PLE/PL analysis,and the main achievements of this work are summarized as follows.Inserting RE(hfa)3(H2O)3(RE=Y or Tb)into the interlayer of LRH by hydrothermal processing yielded,an inorganic/organic hybrid swollen product,whose basal spacing was expanded from?0.89 nm to?1.36 nm,thus inducing the particle thickness expanding from 20 nm to 1?m.Due to the obviously weakened interaction between the interlayers through inserting RE(hfa)3(H2O)3,ultra thin nanosheets with a lateral size of?1 ?m and a thickness of?2.2 nm were obtained via dispersing the swollen LRH in formamide under magnetic stirring for 120 h.For the swollen LRH inserted with Tb(hfa)3(H2O)3,increasing the temperature resulted in decreased intensity of emission at 489 nm(5D4-7F6 transition)and 545 nm(5D4-7F5 transition)of Tb3+and enhanced intensity of emission at 617 nm(5D0-7F2 transition)of Eu3+,along with the CIE color coordinates changing from green to yellow.Under 254 nm excitation from a UV lamp,the swollen LRH emitted tunable color from green,yellow tand then to pink by verying the temperature from 77 K to 360 K,indicating a thermosensitive photoluminescence behavior.One-dimensional and two-dimensional thermosensitive photoluminescence sensors were prepared by dispersing the swollen LRH into PVA.The one-dimensional sensor can detect the temperature variation from-196? to room temperature and thus simulate a temperature variation curve.While the distribution of three temperature rigions along with a distribution diagram can be obtained by using the two-dimensional sensor.Grafting Tb(hfa)3(H2O)3 on the LRH nanosheets yielded a novel functional phosphor film,which exhibited a thermosensitive luminescence behavior similar to that of swollen LRH.Finally,novel optical fiber temperature sensors capable of detection in extreme and dangerous environment were fabricated by coating the complex film on optical fiber.