Neodymium disilicate ceramic pigment synthesized by solid-state method with pre-grinding and mineralizer

Shanjun Ke,Yanmin Wang,Zhidong Pan,He-Ping Zeng 한양대학교 세라믹연구소 2019 Journal of Ceramic Processing Research Vol.20 No.3

A ceramic pigment of neodymium disilicate (i.e., Nd2Si2O7) was synthesized via solid-state reaction with pre-grinding assistanceand a mineralizer. The effects of pre-grinding and mineralizer (i.e., lithium chloride, boric acid and calcium fluoride) on thephase, microstructure and coloring properties of ceramic pigment were investigated by differential thermal analysis, X-raydiffraction, scanning electron microscopy and reflectance spectra in the visible range from 400 nm to 700 nm, respectively. Theresults show that the reaction temperature of Nd2Si2O7 can be decreased by pre-grinding, and the temperature of forming soleNd2Si2O7 phase is further decreased by 200 oC when lithium chloride is used as a mineralizer. Boric acid as a mineralizer canlead to an uneven distribution of Nd and Si components. The sample synthesized with calcium fluoride as a mineralizer cannotobtain Nd2Si2O7 phase. Nd2Si2O7 can be synthesized effectively when lithium chloride is used as a mineralizer.

Kaolin을 이용한 Mullite 합성에 미치는 광화제 첨가 효과

임병수,강경인,소유영,박성,이병하,Lim, Byung-Soo,Kang, Kyong-In,So, You-Young,Park, Sung,Lee, Byung-Ha 한국세라믹학회 1999 한국세라믹학회지 Vol.36 No.1

본 연구에서는 fine ceramics의 합성법을 traditional ceramics 합성에 적용하여 합성한 내화재료용 mullite에 광화제를 첨가함으로서 광화제가 mullite 생성에 미치는 영향을 관찰하고자 한다. 출발물질로 하동 kaolin과 boehmite를 사용하였으며, 여기에 광화제로 MnO와 TiO2를 액상으로 첨가하였다. 그 결과 3.5 wt% MnO를 첨가한 경우, 1,25$0^{\circ}C$에서 미반응 silica와 alumina가 존재하지 않는 단일상의 mullite를 합성할 수 있었으며, TiO2 첨가시 2~3.5wt% MnO의 경우 mullite 생성 온도를 약 10$0^{\circ}C$ 낮출 수 있었다. 이때의 mullite 생성율은 1$650^{\circ}C$에서 84%이며, 부피 비중과 흡수율 및 상온에서 꺾임강도는 각각 2.72, 0.27%, 180MPa을 나타내어 광화제를 첨가하지 않은 경우보다 특성도 향상함을 알 수 있었다. In this study, the formation of mullite phase with mineralizer have been investiagated Hadong Kaolin and boehmite were used as starting materials and also of TiCl4 and MnCl4 aquous solution were used as a mineralizer. In the addition of 3.5% MnO as a mineralizer, mullite single phase could be obtained at 125$0^{\circ}C$ without any other second phases. However in the addition of TiO2 as a mineralizer, mullite single phase is obtained at above 135$0^{\circ}C$. Therefore the formation of mullite is lowered in the case of MnO as a mineralizer than of TiO2. Because it is easy to obtain mullite single phase in the case of MnO addition, all the characteristics improved. The values of bulk density, water absorption and bending strength at room temperature were 2.72g/㎤, 0.27% and 180 MPa, respectively.

ZnO-Al₂O₃-Cr₂O₃ 계 안료 합성 및 유약에서의 발색

최수녕,이용석,이병하,Choi, Soo-Nyong,Lee, Yong-Seok,Lee, Byung-Ha 한국세라믹학회 2008 한국세라믹학회지 Vol.45 No.5

$ZnAl_{1-x}\;Cr_xO_4$ solid solutions were synthesized as pink pigments with and without mineralizer. The pigments were examined to optimize color development conditions of temperature and $Cr_2O_3$ contents. The characteristics of synthesized pigments were analyzed by XRD, XPS, FT-IR and UV-vis spectrophotometer. While samples without mineralizer fired at $1300^{\circ}C$, showed $ZnAl_2O_4$ and $ZnCr_2O_4$ spinel in XRD analysis. While samples with mineralizer resulted in $ZnAl_2O_4$. As a results, the pigments show pink color and most effective pink color was obtained at X=0.15 and $1250^{\circ}C$ when mineralizer was used. The chromatic coordinates are $L^*$ 58.61 $a^*$ 24.48, and $b^*$ 9.60.

수열법에 의한 $CaTiO_3$분말 합성 시 광화제와 농도가 입자형상에 미치는 영향

정항철,서동석,이종국 한국결정성장학회 2002 韓國結晶成長學會誌 Vol.12 No.6

아나타제형 $TiO_2$, 분말과 $Ca(OH)_2$ 분말을 출발물질로 하여 광화제로 KOH 및 NaOH를 각각 첨가한 후, 오토클레이브 내에서 수열반응시켜 perovskite구조를 갖는 $CaTiO_3$, 분말을 제조하였다. $CaTiO_3$, 분말 합성 시 광화제의 종류 및 농도에 따른 결정상 변화와 입자 형상 및 크기를 고찰한 결과, 광화제로 1 N KOH 용액을 사용한 경우, 약 0.7$\mu$m 크기의 구형입자가 합성되었고, 10 N KOH 용액을 사용한 경우, 3 $\mu$m 정도의 육면체형 입자로 합성되었다. 광화제인 KOH 농도가 증가함에 따라 구형입자로부터 육면체형 입자로 형상이 변화되었으며, 입자의 크기도 증가하였다. 1 N NaOH 용액을 광화제로 사용한 경우에는 0.5~1 $\mu$m 정도의 구형입자가 합성되었고, 10 N NaOH 용액을 사용한 경우에는 1~4 $\mu$m 정도의 육면체 형상을 갖는 입자와 10$\mu$m 이상인 휘스커형 입자가 혼합된 형상으로 합성되었다. KOH 광화제와 마찬가지로 NaOH 광화제의 농도가 증가함에 따라 육면체 및 휘스커 형상을 갖는 입자로 변화하였으며, 입자의 크기도 아울러 증가하였다. 성분 분석 결과 휘스커 형상의 입자의 경우에는 육면체형 입자에서 관찰된 sodium성분이 검출되지 않았다. The $CaTio_3$powder with perovskite structure was synthesized by mixing anatase $TiO_2$and $Ca(OH)_2$powders as starting materials, and KOH or NaOH as mineralizer, followed by hydrothermal method. The change of crystal structure, particle shape and size of the synthesized $CaTiO_3$powder was investigated with kind and concentration of mineralizer. It was found that the spherical particles of 0.7 $\mu$m were obtained when using 1N KOH and the hexahedrons particles of 3$\mu$m were obtained for the case of using 10 N KOH. With increasing KOH concentration, the particle shape was changed from sphere to hexahedrons and its size also increased. When using 1 N NaOH, the powder was consisted of 0.5~1 $\mu$m particle in size, whereas hexahedrons of 1~4 $\mu$m and whiskers more than 10$\mu$m in size was obtained for the 10 N NaOH solution. With increasing NaOH concentration, the particle shape was varied from hexahedrons to whiskers, showing the similar result with the KOH case. It was confirmed from EDS analysis that Na element, which was detected in hexahedrones was not contained in the whiskers.

CHISELED NICKEL HYDROXIDE NANOPLATES GROWTH ON GRAPHENE SHEETS FOR LITHIUM ION BATTERIES

LEI-LEI TIAN,XIAN-YONG WEI,QUAN-CHAO ZHUANG,CHAO WU,RUI-LUN XIE,ZHI-MIN ZONG,YONG-LI CUI,SHI-GANG SUN 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2013 NANO Vol.8 No.6

The morphologies and structures of Ni(OH)2–graphene hybrid materials were tailored by using different mineralizers in this work. It was revealed that the synergic effects of the highly oxidized graphene sheets and the mineralizers played a crucial role in controlling the morphology and structure of the nanocomposites, and Na2CO3 is a very effective mineralizer for growing chiseled 2D nanoplates of Ni(OH)2 on graphene sheets. When produced with NaOH, fragmental Ni(OH)2 crystals with irregular shapes erratically decorated on graphene sheets. In contrast, chiseled Ni(OH)2 hexagonal nanoplates grown on graphene sheets were obtained when Na2CO3 was used as the mineralizer. These unique 2D–2D nanoarchitectures with higher contact area between the nanocrystals and graphene substrate can increase the interfacial interaction and then efficiently improve the structural stability of the composite material, thus exhibiting an enhanced Li storage capacity and excellent cycling performance of 562 mAh g-1 after the 36th cycle.

수열합성법으로 제조된 PZT 분말의 특성

양범석,이혁희,원창환,Yang, Beom-Seok,Lee, Huk-Hee,Won, Chang-Whan 한국세라믹학회 2005 한국세라믹학회지 Vol.42 No.7

Conditions for formation of perovskite Pb(Zr$_{0.52}$Ti$_{0.48}$)O$_{3}$ phase by the hydrothermal synthesis are investigated. Pb(Zr$_{0.52}$ Ti$_{0.48}$)O$_{3}$ ceramics were synthesized by hydrothermal process above 180$^{\circ}C$ for 2 h reaction using 5$\~$30 M KOH solution as a mineralizer. Particle size increases in proportion to the mineralizer concentration. As a result of EOX analysis, PZT powders synthesized using 50 M of KOH as a mineralizer were considered as 2.42 mol$\%$ K doped-PZT powders. And 2.42 mol$\%$ K doped-PZT has much higher mechanical quality factor than undoped PZT ceramics. The sintering properties showed 7.987 g/cm$^{3}$ of sintered density and 3$\~$4 $\mu$m of grain size.

불소 함유 반도체 슬러지를 활용한 저온 소성 기술로 제조된 백색 포틀랜드 시멘트 클링커 특성

박수현(Su-Hyeon Park),나현엽(Hyun-Yeop Na),황봉춘(Bong-Choon Hwang),엄주일(Ju-il Eom),김윤용(Yun-Yong Kim) 한국건설순환자원학회 2024 한국건설순환자원학회 논문집 Vol.12 No.2

본 논문에서는 산업부산물인 불소 함유 반도체 슬러지를 재활용하기 위하여 광화제로써 시멘트 클링커 소성온도 저감 효과를 증명하기 위하여 시멘트 클링커 및 시멘트 품질에 미치는 영향을 연구하였다. 또한, 기존 광화제로 사용되는 천연 형석을 사용하였을 때의 온도별 클링커 및 시멘트 특성을 비교하기 위한 검증 연구도 진행됐다. 연구 결과, 반도체 슬러지는 광화제로써 충분한 효과를 보여지고 있으며, 기존 광화제인 천연형석을 대체할 수 있는 것으로 나타났다. In this paper, the effect on cement clinker and cement quality was studied to prove the effect of reducing the sintering temperature of cement c linker as a mineralizer to recycle fluorine based semiconductor sludge, an industrial by-product. In addition, a verification study was conducted to compare the properties of clinker and cement at different temperatures when natural fluorite, previously used as a mineralizer, was used. As a result of the study, semiconductor sludge showed sufficient effectiveness as a mineralizer and could replace natural fluorite, an existing mineralizer.

생체재료용 Y-PSZ 분말의 특성에 미치는 수열합성 후 열처리 영향

이종현,원창환,김문환,김채성 한국생체재료학회 2003 생체재료학회지 Vol.7 No.1

One of the obstacle of Y-PSZ for the application of biomaterials is their in-vivo failures by low-temperature degradation (LTD). The loss in strength is attributed to the transformation of tetragonal grains to monoclinic. The LTD can be effectively minimized by decreasing grain size. The purpose of this study was to synthesize nano sized Y-PSZ powder and to investigate crystallization behavior with calcination temperature. For this, 3 mol% Y2O3-doped Zirconia powders were prepared by hydrothermal synthesis from ZrOCl2 • 8H2O, YCl3 • 6H2O and KOH as starting chemicals. The crystallization behavior of zirconia gel during the synthesis was investigated by XRD and FESEM as functions of the mole ratio of mineralizer and heat treatment temperature. An increased crystallization rate of nano YSZ was observed with increasing the concentration of mineralizer. Phase transition procedure during the post heat treatment process is presented.

수열합성법으로 제조된 PZT 분말의 특성에 미치는 광화제 농도와 출발물질의 영향

양범석,윤기석,박영철,원창환,Yang, Beom-Seok,Yun, Ki-Seok,Park, Young-Chul,Won, Chang-Whan 한국세라믹학회 2005 한국세라믹학회지 Vol.42 No.11

The effect of reaction parameters in the characteristic of $Pb(Zr_{0.52} Ti_{0.48})O_3$ powders by hydrothermal process was investigated in this study. In the preparation of PZT, the types of starting material and concentration of mineralizer on phase fraction and morphology was investigated respectively. Regardless the types of Pb precursor, PZT was able to synthesize ranging from 7 to 20 on KOH concentration and from 13.01 to 13.55 on pH of solution. The particle size of the PZT powders can be controlled by the mineralizer concentration and various types of precursor.

Synthesis of ZnO- Al₂O3-Cr₂O3 System Pigments with CrCl3

최수녕,이병하 한국세라믹학회 2009 한국세라믹학회지 Vol.46 No.4

The coloring agents Cr₂O₃ and CrCl₃ were manipulated in this study to synthesize ZnO-Al₂O₃-Cr₂O₃ system pigments by changing their mixing ratio. The addition of varying amounts of mineralizer was also tested to obtain better color development of the pink pigment. In the synthesis of ZnO- Al(OH)₃-Cr₂O₃-CrCl₃ pigments, the best composition is Cr₂O₃-0.1 mole and CrCl₃-0.2 mole when Cr₂O₃ is partially substituted with CrCl₃ to synthesize them. Among the ZnAl1.6-xCr0.2+xO₄ compositions to which a mineralizer was not added, ZnO-1mole, Al(OH)₃-1.7 mole, Cr₂O₃-0.075 mole, and CrCl₃-0.15 mole showed a desirable pink hue. The measurements of pigments L*, a* and b*, were L* 81.81, a* 16.65 and b* 0.45, and when the synthesized pigments were applied to a zinc glaze, the measurements were L* 60.41, a* 28.39, and b* 16.97. When adding a mineralizer, a 2 wt% addition resulted in the most favorable pink color. The composition for the most favorable result that included a mineralizer was Al(OH)₃-1.8 mole, Cr₂O₃-0.05 mole, and CrCl₃-0.1 mole, and the calcination temperature was 1250℃. The pigment color analysis showed L* 82.52, a*17.14 and b* -1.18, and the measurements of L*, a* and b* in the glaze were L* 60.97, a* 28.77 and b* 13.72.