SPECTRAL STUDY OF FUNCTIONAL NANOCOMPOSITES BASED ON HUMIC ACIDS FOR WATER TREATMENT Kamila Kydralieva Institute of Chemistry and Chemical Technology, Kyrgyzstan 1 Kaliningrad, July 12, 2017
OUTLINE Why nanocomposites? definitions, examples What are functional nanocomposites? How to produce functional nanocomposites? What set of spectroscopic data are good for? How functional nanocomposites utilize for waste water treatment? 2
What are nanocomposites? Nanocomposites are a class of materials in which one or more phases with nanoscale dimensions are embedded in a metal, ceramic or polymeric matrix. The general idea is to create a synergy between the various constituents, such that novel properties capable of meeting or exceeding design expectations can be achieved. The properties of nanocomposites rely on a range of variables, particularly the matrix material, loading, degree of dispersion, size, shape, and interaction between the matrix and the second phase. 3
Nanocomposites Resulting nanocomposite may exhibit drastically different (often enhanced ) properties than the individual components. Appears green in reflected light and red in transmitted light. Lycurgus Cup is made of glass. Roman ~400 AD, Myth of King Lycurgus http://www.britishmuseum.org/explore/highlights/highlight_objects/pe_mla/t/the_lycurgus_cup.aspx
First nanocomposites: example Technology re- discovered in the 1600s and used for colored stained glass windows. The Institute of Nanotechnology http://www.nano.org.uk/
Nanoeffect • Very high surface area to volume ratios in nanostructures • Nanocomposites provide large interface areas between the constituent, intermixed phases increase in 30 000 000 times prefix “nano” for system is not only thanks to size, but to dependence of system properties from size
MAGNETIC HUMICS-BASED NANOCOMPOSITES fabrication, composition, sorption , structure: Ultrasound spectrometry Mossbauer spectrometry Fluorescence Infrared spectrometry
Case study: Kara-Balta uranium tailing dump inhabited zone Accumulating storage reservoir : Contaminated area is 40-50 km 2 , Total area of TD is 240 ga Depth of reservoir is 110-120 m Depth of underground water – 40-90 m ISTC Project #KR-072, KR-715, KR-1316
APPROACHES TO TECHNOLOGY DEVELOPMENT HA Fe 3 O 4 Chemical coprecipitation ( ex situ, in situ ) Nanocomposite formulation Fe 3 O 4 @HA Mechanochemical dispersion Sorption of radionuclides and HM Fe 3 O 4 @HA/M core - Fe 3 O 4 shell - HA Magnet separation Mechanochemical nanocomposite powders Sorbent regeneration Precursors dispersion (Fe 3 O 4 ,@ НА) Fe 3 O 4 @HA Principal scheme for magnet separation technology
Humic acids of brown coal (HA) Magnetite (Fe 3 O 4 ) • M s = 92-100 А· m 2 /kg (Fe 3 O 4 ) (60-80 for γ -Fe 2 O 3 ) >C=O • simple synthesis • high speed of reaction COOH • high yield of target material • scalability Lecture of Prof • non-toxic, nature-abundant OH Oleg Trubetskoy -NH 2 Fe 3 O 4 nanoparticles Humic acids: • magnetic; • enhance sorption -NH- • provide specific potential for surface composite; • (Sspec – 62 m 2 /g) =NH- • stabilization of Fe 3 O 4 nanoparticles Structure unit of humic acids ( Kleinchempel, 1991 ) • high complex ability (to 10 mmol/g for coal- derived); • S spec ~ 40 m 2 /g HYBRID FUNCTIONAL MATERIALS • sorption capacity – to 7 mg-eq/g ; Sspec to 180 m 2 /g • raw material: coal, peat, sapropel, compost etc. • non-toxic, nature-abundant initial ratio Fe 3 O 4 /HA, wt% (80/20, 50/50, 30/70, 20/80, 10/90);
CHEMICAL METHODS FOR FORMULATION MAGNETITE* Fe 0 Fe(II) Fe(II) + Fe(III) Fe(II) Fe(III) Precursors Fe(III ) 5-8 9 4 1-3 9-11 12 5 1 Solution Fe 2+ Fe 2+ + Fe 3+ Fe 2+ Fe 3+ Fe 3+ formulation 6 7 8 Classification by type of precursors: Fe(OH) 3 Fe(OH) 2 Fe(OH) 3 Fe(OH) 2 1) salt of Fe (II) (variants 1-3); 2,3,12 1,4,5,9 10,11 Fe 2+ Fe 3+ 2) magnetite (variant 4); 3) salts of Fe (II, III) (var. 5-8); 4) salts/oxides of Fe (III) (var. 9-12) 10 2,12 Hydroxides Fe(OH) 2 Fe(OH) 2 + Fe(OH) 3 Fe(OH) 3 deposition 1,2,4-10,12 3 11 Crystallohydrates Fe 3 O 4 · nH 2 O formation 1-12 Final product Fe 3 O 4 chemical coprecipitation Fe + HCl FeCl 2 + H 2 (inert conditions) 2Fe Cl 3 + Fe Cl 2 + 8NH 4 OH Fe 3 O 4 + 8NH 4 Cl + 4H 2 O Fe 3 O 4 + HA + 8NH 4 OH Fe 3 O 4 @HA 11 2FeCl 3 + FeCl 2 + 8NH 4 OH +HA Fe 3 O 4 @HA + 8NH 4 Cl + 4H 2 O *Grabovskiy, 1998, modified
SYNTHESIS of NANOCOMPOSITE Fe 3 O 4 @HA Table 2. List of samples synthesized Synthesis methods Method and Initial ratio of Sample description* condition of precursors, wt % synthesis Coprecipitation in Fe 3 O 4 -HA20*-C 80% Fe 3 O 4 , 20% HA Chemical coprecipitation Mechanochemical argon atmosphere: 2FeCl 3 +FeCl 2 +NH 4 OH+H synthesis Fe 3 O 4 -HA50-C 50% Fe 3 O 4 , 50% HA T= 40 ° C; • high energetic planetary A=Fe 3 O 4 /HA+NH 4 Cl+H 2 O 1000 rpm; Fe 3 O 4 -HA80-C 20% Fe 3 O 4, 80% HA - initial ratio Fe 3 O 4 /HA, grinder SPEX SamplePrep τ с = 20 min 8000 Mixer/Mil, wt% (80/20, 50/50, 30/70, • agate mortar with agate Fe 3 O 4 -HA20-C В 80 % Fe 3 O 4 , 20% HA Coprecipitation in 20/80, 10/90); balls from wolfram Fe 3 O 4 -HA50-C В 50% Fe 3 O 4 , 50% HA air atmosphere: - synthesis atmosphere: carbide; Fe 3 O 4 -HA70-C В 30% Fe 3 O 4 , 70% HA T = 20 ° C; • rate - 1425 rpm; Magnet separation of solution argon and air; 600 rpm; Fe 3 O 4 -HA80-C В 20% Fe 3 O 4 , 80% HA (Nd 2Х2 см , 0.3 T, 7 min, 20% DS, 10 mL) - 40 °С and 22 ± 2 °С • initial ratio of Fe 3 O 4 and τ с = 20 min Fe 3 O 4 -HA90-C В 10% Fe 3 O 4 , 90% HA HA, wt% (80/20, 50/50, 20/80); Fe 3 O 4 -HA20-M10 80% Fe 3 O 4 , 20% HA Mechanochemical • m balls /m о (7/ 1 и 4 /1); Tombach et al. (2006), Liu et synthesis: m balls /m s Fe 3 O 4 -HA50-M10 50% Fe 3 O 4 , 50% HA • τ (2 ÷ 60 min) al. (2008) = 7/1; τ d = 10 min Fe 3 O 4 -HA80-M10 20% Fe 3 O 4 , 80% HA • chemical precipiation ex situ Fe 3 O 4 -HA20-M30 80% Fe 3 O 4 , 20% HA • synthesis at ~10 wt % HA Mechanochemical Fe 3 O 4 -HA50-M30 50% Fe 3 O 4 , 50% HA synthesis: m balls /m s = 7/1; τ d = 30 min Fe 3 O 4 -HA80-M30 20% Fe 3 O 4 , 80% HA T – synthesis temperature, rpm – rate of stirring, rotation per minute, τ – Zaripova, Kydralieva, et al. J Biol Physics & Chem , 2008 synthesis time, τ – dispersion time, m balls /m sample - m balls /m s , * number Patent RU 2547496 С 2RU от 10.07.2012. index in sample description indicates initial ratio of HA into Kydralieva, Yurishcheva, et al. J Inorg Org Polym Mater. 2016. composition, in wt% Review
ULTRASOUND SPECTROSCOPY: HYDRODYNAMIC SIZE 3 2.4 2.4 a b 2.0 2.0 PSD, weight basis PSD, weight basis 2 1.6 1.6 Average hydrodynamic size 1.2 1.2 for nanocomposites < d > 12, 1 0.8 0.8 Sample nm 0.4 0.4 Fe 3 O 4 184 0 0.0 0.0 Fe 3 O 4 /ГК20 157 -3 -2 -1 0 -3 1 -3 -2 -1 0 1 10 10 10 10 10 10 10 10 10 10 10 Diameter [um] Diameter [um] Fe 3 O 4 /ГК50 122 Histograms of particle size distribution for as-prepared Fe 3 O 4 /ГК80 106 magnetite (a) and in 14 days of solution (b) (DT-1200, Dispersion Technology, 22 ± 2 ° C, 10 g/L) There is a narrow particle size distribution for as-prepared Fe 3 O 4 . The average hydrodynamic particle size was ~ 180 nm. In 14 days of storage of the original magnetite the redistribution in size and enlargement of the dispersed system are observed.
STRUCTURE of NANOCOMPOSITES Fe 3 O 4 -HA20-M10 Fe 3 O 4 -HA50-C 100 200 нм нм Fe 3 O 4-C Fe3O4 Fe 3 O 4 - ГК 20-C I, отн. ед. I, отн. ед. Fe3O4- ГК 20-M10 Fe 3 O 4 - ГК 50-C Fe3O4- ГК 50-M10 Fe 3 O 4 - ГК 80-C Fe3O4- ГК 80-M10 ГК ГК 20 40 60 80 100 120 20 40 60 80 100 120 2 2 XRD analysis of hybrid nanocomposites synthesized by coprecipitation and mechanochemical dispersion (m balls /m sample =7/1) (DRON-UM-2, Cu(K a ), 1 о /min) Table 3. Particle size of magnetite according XRD ( data processing by Fityk) Major phase formed during both synthesis method in the Sample Particle size, nm presence of humic acids in situ is a magnetite Fe 3 O 4 . Fe 3 O 4 9,2 ± 0,18 Fe 3 O 4 -HA20-C 8,2 ± 0,12 The HA bind to the particles just after nucleation of the Fe 3 O 4 -HA50-C 7,3 ± 0,13 Fe 3 O 4 nanoparticles preventing further growth. Fe 3 O 4 -HA80-C 5,7 ± 0,20 According to SEM more uniform distribution was observed Fe 3 O 4 -HA20-M10 8,7 ± 0,21 for samples synthesized by coprecipitation (SUPRA 55VP- Fe 3 O 4 -HA50-M10 7,8 ± 0,28 32-49, 150000 × ). Fe 3 O 4 -HA80-M10 5,8 ± 0,25
STRUCTURE of NANOCOMPOSITES 300 К Mossbauer spectra for nanocomposites at 300 К and 5 К (М S-1101-E, Mostec, helium cryostat SHI-850-5 (4.5 ÷ 500 K), 57 Co in matrix of Rh, etalon is -Fe) In Mossbauer spectra quadruple doublet corresponding to 57 Fe atoms in octahedral surrounding of oxygen is observed. Intensity of doublet correlates with increase of HA content. Size of particles made d (Fe 3 O 4 -HA20-C) = 13,5 ± 0,1 nm, In collaboration with Dr Natalia d (Fe 3 O 4 -HA50-C) = 12,3 ± 0,1 nm. Chistyakova Fe 3 O 4 -HA50- М10 is maggemite ( γ -Fe 2 O 3 ).
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