SYNTHESIS AND PROPERTIES OF SUPRAMOLECULAR COMPOUNDS ON THE BASE OF LAYERED DOUBLE HYDROXIDES
This presentation is the property of its rightful owner.
Sponsored Links
1 / 13

SYNTHESIS AND PROPERTIES OF SUPRAMOLECULAR COMPOUNDS ON THE BASE OF LAYERED DOUBLE HYDROXIDES PowerPoint PPT Presentation


  • 163 Views
  • Uploaded on
  • Presentation posted in: General

SYNTHESIS AND PROPERTIES OF SUPRAMOLECULAR COMPOUNDS ON THE BASE OF LAYERED DOUBLE HYDROXIDES. Isupov V . P ., Tarasov K . A ., Chupakhina L . E ., Mitrofanova R. P ., Starikova E . V. Institute of Solid State Chemistry and Mechanochemistry SB RAS Kutateladze-18, Novosibirsk, 630128

Download Presentation

SYNTHESIS AND PROPERTIES OF SUPRAMOLECULAR COMPOUNDS ON THE BASE OF LAYERED DOUBLE HYDROXIDES

An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -

Presentation Transcript


Synthesis and properties of supramolecular compounds on the base of layered double hydroxides

SYNTHESIS AND PROPERTIES OF SUPRAMOLECULAR COMPOUNDS ON THE BASE OF LAYERED DOUBLE HYDROXIDES

Isupov V.P., TarasovK.A., ChupakhinaL.E., Mitrofanova R.P.,StarikovaE.V.

Institute of Solid State Chemistry and Mechanochemistry SB RAS

Kutateladze-18, Novosibirsk, 630128

Novosibirsk State University,

Pirogova-2, Novosibirsk, 630090

E-mail:[email protected]


Synthesis and properties of supramolecular compounds on the base of layered double hydroxides

  • General formula of layered double hydroxyde (LDH):

  • [M(II)(1-X)M(III)X(OH)2]Y+(An-Y/n)mH2O

  • M(II)= Mg2+, Ni2+, Co2+, Zn2+, Ca2+, etc.

  • M(III)=Al3+, Cr3+, Fe3+, Mn3+, etc.

  • An- -interlayer anions

  • For Li+: [LiAl2(OH)6]+nAn-·mH2O

  • Fig. 1. Structure of LDH with anions and water molecules in the interlayer space.


Synthesis and properties of supramolecular compounds on the base of layered double hydroxides

Methods of LDHs synthesis:

  • Coprecipitation of LDH from basic solutions containing salts of M2+and M3+:

  • (1-x)M(II) + xM(III) + 2(OH)- + Y/nAn- + mH2O =

  • [M(II)(1-x)M(III)x(OH)2]Y+(An-Y/n)·mH2O

  • Large amount of wastes

  • Poor crystallinity of products

  • Restriction in the value of X in the product composition to the range 0,2-0,3

  • Topotaxial reactions

  • Anion exchange method:

  • [M(II)(1-x)M(III)x(OH)2]Y+(An-Y/n)·mH2O +Bm- 

  • [M(II)(1-x)M(III)x(OH)2]Y+(Bm-Y/m)·nH2O + An-


  • Synthesis and properties of supramolecular compounds on the base of layered double hydroxides

    Direct intercalation Li+ salts into the Al(OH)3

    LinX + 2nAl(OH)3 + mH2O = [LiAl2(OH)6]nX·mH2O

    Fig. 2. Scheme of intercalation of Li salts into Al(OH)3


    Synthesis and properties of supramolecular compounds on the base of layered double hydroxides

    Mechanochemical activation of mixture

    of hydroxides of divalent metalsand salts of M3+

    • 3Mg(OH)2 + AlCl36H2O = [Mg2Al(OH)6]ClnH2O + MgCl2

  • (for example)

  • Fig.3. Powder X-ray diffraction patterns of various samples:

    1- initial Mg(OH)2,

    2-5 - products of mechanical treatment

    of Mg(OH)2 with aluminium salts.

    Time of treatment - 3 min (2),

    15 min (3,4,5).

    Aluminium salts- AlCl36H2O (2,3), Al(NO3)39H2O (4), Al2(SO4)318H2O (5).

    0 10 20 30 40

    2


    Synthesis and properties of supramolecular compounds on the base of layered double hydroxides

    Interaction of dawsonite and salts

    of transition metals and Mg2+

    • NaAl(OH)2CO3 – basic carbonate of sodium and aluminium or dawsonite

    Fig. 4. Interaction dawsonite with aqueous solution of Ni(NO3)2 (Ni/Al=0.5)

    2


    Synthesis and properties of supramolecular compounds on the base of layered double hydroxides

    Probable scheme of interaction of dawsonite and Ni(NO3)2


    Synthesis and properties of supramolecular compounds on the base of layered double hydroxides

    Proposed methods of LDHs synthesis:

    Direct intercalation Li+ salts into the Al(OH)3

    Mechanochemical activation of mixture

    of hydroxides of divalent metalsand salts of M3+

    Interaction of dawsonite and salts

    of transition metals and Mg2+


    Synthesis and properties of supramolecular compounds on the base of layered double hydroxides

    X-ray diffraction pattern of supramolecular compounds

    on the base of Li-Al layered double hydroxide

    Fig.5. X-ray diffraction pattern:

    1 - Li-Al-Cl,

    2 - Li-Al-Co(edta),

    3 - Li-Al-Cu(edta),

    4 - Li-Al-Ni(edta).


    Synthesis and properties of supramolecular compounds on the base of layered double hydroxides

    Scheme supramolecular system on the base of Li-Al LDH

    Fig. 6. Sheme of Li-Al-M(edta) without water molecules

    (1 - N, 2 - O, 3 - M, 4 - C)


    Synthesis and properties of supramolecular compounds on the base of layered double hydroxides

    Termal decomposition of [LiAl2(OH)6]2[Medta]·mH2O

    (M=Ni2+, Cu2+, Сo2+)

    Electron microscopic studies (SEM and TEM) of the products formed during thermal desomposition of the intercalates LiAl2(OH)6]2[Cuedta]·4H2O and [LiAl2(OH)6]2[Coedta]·4H2Oshowed that the decomposition is accompanied by the formation of nano-crystal metal particles with a size from 2 to 100 nm distributed chaotically both over the volume and on the surface of the amorphous oxide matrix. In the case of thermal decomposition of [LiAl2(OH)6]2[Niedta]·4H2O, the size of the formed nano-sized nickel particles is close to 5 nm, their size disrtibution being very narrow. The mean distance between nickel particlesin the amorphous matrix is 20 nm.

    LDH-Niedta (4000 C)

    LDH-Cuedta (4000 C)

    LDH-Coedta (4500 C)

    LDH-Coedta (4500 C)


    Synthesis and properties of supramolecular compounds on the base of layered double hydroxides

    Conclusions

    1. New methods of LDHs synthesis can be based on topotaxial reactions.

    • 2. It have been shown a possibility of using the obtained LDHs as matrixes for preparation the supramolecular compounds with layered structure, containing complex anions:[M(edta)]2-(M - Ni, Cu, Co, Zn, Pb, Mg, Mn), [Fe(edta)(OH)]2-, [M(nta)]- (M - Ni, Cu, Co).

    • 3. It have been shown a possibility of using the obtained LDHs as matrixes for preparation the composite materials containing nanosized particles of various metals.

    The investigation was supported by the Program "Scientific Research in Higher School into the Priority Directions of Science and Technology" (Grant N 3Н-118-01) and the Russian Foundation for Basic Research (Grant 02-03-32066).


    Synthesis and properties of supramolecular compounds on the base of layered double hydroxides

    Thank you for listening...

    The end


  • Login