層狀材料簡(jiǎn)介

1、12500 km diameter8-35 km crust% by weight in crustO= 49.2Si= 25.7Al= 7.5Fe= 4.7Ca= 3.4Na= 2.6K= 2.4Mg= 1.9other = 2.682.4%Elements of Earth0.26 nmoxygensilicon0.29 nmaluminium or magnesiumhydroxyl or oxygen硅氧四面體硅氧四面體鋁氧八面體鋁氧八面體Clay minerals are hydrous aluminium phyllosilicates, sometimes with variab

2、le amounts of iron, magnesium, alkali metals, alkaline earths, and other cations. Basic Structural UnitsIntroduction of clay minerals1. Kaolinite used in paints, paper, pottery and pharmaceutical industries (OH)8Al4Si4O10 known as china clay, white clay, or kaolinClassification of clay minerals cati

3、on exchange capacity, and affinity to water (OH)4Al4Si8O20nH2O used as drilling mud, in slurry trench walls, stopping leaks2. Montmorillonite3. Illite used in manufacturing of brick and tile, molding sands, storing radioactive wastesKAl2(Al,Si)Si3O10(OH)2nH2O non-expanding, dioctahedral, micaceous m

4、inerals 4. Layered double hydroxides (LDHs) used as catalyst, additives in polymers, precursors to magnetic, and in biology and medicine. M2+1-xM3+x(OH)2x+(An)x/nmH2O the sole layered clay with anion-exchangable capabilityMineralSpecific surface(m2/g)Ion exchange capacities (meq/100g)Montmorillonite

5、80080-120Illite80-10020-30Kaolinite10-203-10LDHs10-40100-470A ComparisonLDHsLDHs發(fā)展歷史發(fā)展歷史 1990s1970s194218421960s首次發(fā)現(xiàn)天然水滑石礦物首次發(fā)現(xiàn)天然水滑石礦物 首次人工合成出了水滑石首次人工合成出了水滑石Kyowa公司將水滑石的合成工業(yè)化；公司將水滑石的合成工業(yè)化；Allmann首次首次確認(rèn)了水滑石的層狀結(jié)構(gòu)確認(rèn)了水滑石的層狀結(jié)構(gòu) 基于超分子化學(xué)定義及插層組基于超分子化學(xué)定義及插層組裝概念，使得水滑石展示了更裝概念，使得水滑石展示了更為廣闊的應(yīng)用前景為廣闊的應(yīng)用前景 對(duì)水滑石性能進(jìn)行了

6、詳細(xì)研究，尤其是在對(duì)水滑石性能進(jìn)行了詳細(xì)研究，尤其是在催化反應(yīng)中的應(yīng)用催化反應(yīng)中的應(yīng)用M2+1-xM3+x(OH)2x+(An)x/nmH2O 主體層板主體層板層間離子層間離子OHHAn-An-OHHM2M3OOM2OOM3OOOOOOOHHOHHM2M3OOM2OOM3OOOOOOLDHsLDHs結(jié)構(gòu)結(jié)構(gòu) 主體層板主體層板LDHsLDHs 特特 征征 層板元素層板元素層板電荷密度層板電荷密度客體種類客體種類層間距層間距M2+/M3+=2M2+/M3+=3M2+/M3+=4CO2CO2CO2CO2OOOCO32CO32a) Ni-Al, Ni-Fe, Zn-Crb) Mg-Ni-Fe, Cu-

7、Zn-Alc) Cu-Ni-Mg-Al無(wú)機(jī)陰離子無(wú)機(jī)陰離子有機(jī)陰離子有機(jī)陰離子配合物陰離子配合物陰離子雜多陰離子雜多陰離子等等共沉淀共沉淀 返混返混/ /沉淀沉淀 LDHsLDHs插插層組裝層組裝方法方法 離子交換離子交換水熱合成水熱合成二次組裝二次組裝焙燒復(fù)原焙燒復(fù)原 LDHsLDHs制備方法制備方法 LDHsLDHs表征方法表征方法XRDFT-IRMAS NMRTG/DTASEM、TEMTPDTPDEBETXAFSIn-situHTXRDIn-situ IRIn-situEDXRD熱穩(wěn)定性熱穩(wěn)定性 酸堿雙功能性酸堿雙功能性 層間離子的可交換性層間離子的可交換性 組成和結(jié)構(gòu)的可控性組成和結(jié)構(gòu)的可控性記憶效應(yīng)