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Superparamagnetic Nanostructured Materials Superparamagnetische Nanostrukturierte Materialien Materiaux Nanostructures Superparamagnetiques

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Superparamagnetic Nanostructured Materials Superparamagnetische Nanostrukturierte Materialien Materiaux Nanostructures Superparamagnetiques (19) & (11) EP 1 397 243 B1 (12) EUROPEAN PATENT SPECIFICATION (45) Date of publication and mention (51) Int Cl.: of the grant of the patent: B32B 5/16 (2006.01) B32B 9/00 (2006.01) 31.08.2011 Bulletin 2011/35 B32B 15/02 (2006.01) B32B 17/02 (2006.01) B32B 19/00 (2006.01) B32B 21/02 (2006.01) (2006.01) (2006.01) (21) Application number: 02802541.9 B32B 23/02 B32B 27/02 B03C 1/00 (2006.01) H01F 1/00 (2006.01) (22) Date of filing: 12.04.2002 (86) International application number: PCT/US2002/008259 (87) International publication number: WO 2003/049936 (19.06.2003 Gazette 2003/25) (54) SUPERPARAMAGNETIC NANOSTRUCTURED MATERIALS SUPERPARAMAGNETISCHE NANOSTRUKTURIERTE MATERIALIEN MATERIAUX NANOSTRUCTURES SUPERPARAMAGNETIQUES (84) Designated Contracting States: • SATO MICHI ET AL: "Dilution effect on magnetic AT BE CH CY DE DK ES FI FR GB GR IE IT LI LU properties of Co3O4 nanocrystals" JOURNAL OF MC NL PT SE TR APPLIED PHYSICS, AMERICAN INSTITUTE OF PHYSICS. NEW YORK, US, vol. 88, no. 5, 1 (30) Priority: 13.04.2001 US 283354 P September 2000 (2000-09-01), pages 2771-2774, XP012051496 ISSN: 0021-8979 (43) Date of publication of application: • ULRICH R ET AL: "NANO-OBJECTS WITH 17.03.2004 Bulletin 2004/12 CONTROLLED SHAPE, SIZE, AND COMPOSITION FROM BLOCK COPOLYMER (73) Proprietor: CORNELL RESEARCH FOUNDATION, MESOPHASES" ADVANCED MATERIALS, INC. WILEY VCH, WEINHEIM, DE, vol. 11, no. 2, 22 Ithaca, NY 14850 (US) January 1999 (1999-01-22), pages 141-146, XP000877978 ISSN: 0935-9648 (72) Inventors: • S.R: AHMED ET AL: "Synthesis and magnetic • GARCIA, Carlos, properties of block copolymer-CoFe2O4 Cornell University-MSE Department nanoclusters" MATERIAL RESEARCH Ithaca, NY 14850 (US) SYMPOSIUM PROCEEDINGS, vol. 661, 2001, • WIESNER, Ulrich, pages KK10.10.1-KK10.10.6, XP002483569 ISBN: Cornell University 1558995714 Ithaca, NY 14853 (US) • B.H. SOHN: "Processible optically transparent block copolymer films containing (74) Representative: Stones, James Alexander superparamagnetic iron oxide nanoclusters" Beck Greener CHEMISTRYOF MATERIALS, vol. 9, January 1997 Fulwood House (1997-01), pages 264-269, XP002483570 12 Fulwood Place • LI G. ET AL: ’An effective synthetic route for a London WC1V 6HR (GB) novel electrolyte: nanocrystalline solid solutions’ ADV. MATER. vol. 11, no. 2, 1999, (56) References cited: pages 146 - 149, XP000877979 DE-A1- 19 738 913 • ULRICH R. ET AL: ’Nono- objects with controlled shape, size and composition from block copolymer mesophases’ ADV. MATER. vol. 11, no. 2, 1999, pages 141 - 145, XP002960653 Note: Within nine months of the publication of the mention of the grant of the European patent in the European Patent Bulletin, any person may give notice to the European Patent Office of opposition to that patent, in accordance with the Implementing Regulations. Notice of opposition shall not be deemed to have been filed until the opposition fee has been paid. (Art. 99(1) European Patent Convention). EP 1 397 243 B1 Printed by Jouve, 75001 PARIS (FR) (Cont. next page) EP 1 397 243 B1 • FINNEFROCKA.C. ET AL: ’Metal oxide containing mesoporous silica...’ ANGEW. CHEM. INT. ED. vol. 40, no. 7, 2001, pages 1208 - 1210, XP002960652 2 1 EP 1 397 243 B1 2 Description Moving to the late 1990s, more extensive magnetic measurements were reported on bulk iron silicate com- BACKGROUND OF THE INVENTION posites. Several systems involving silica precursors and iron alkoxides or iron salts produced the phase, γ-Fe2O3 1. Field of the Invention 5 (maghemite), which in bulk form is ferromagnetic. The γ- Fe2O3 particles found in the silicates were below the crit- [0001] The invention relates generally to superpara- ical size for ferromagnetism resulting, however, in super- magnetic nanostructured materials and a method for paramagnetic behavior of the composites. Superpara- making the same. magnetic iron (III) nanoparticles were produced having 10 a narrow size distribution, 4-6 nm, with varying degrees 2. Background Information of iron salt content. It was determined that a transition to ferromagnetism occurs at lower temperatures and in- [0002] Engineering synthetic materials towards the creased particle size. The transition was clarified to indi- molecular architecture of biological molecules is a pow- cate that at low concentrations of Fe2O3 the change oc- erful concept. These synthetic materials may be efficient- 15 curs at a particle size of 5 nm. Most studies included the ly integrated with biological molecules for further detec- effects of thermal treatmentson silica compositesto max- tion or targeting of biological tissues. Synthetic material imize magnetization. Two factors contributed to predict- that is fabricated near an atomic length scale ~10 nm is ing the magnetic moment of an iron silicate, the concen- particularly challenging since this is a lower limit on which tration of iron to that of silica and the various temperature important biological processes and mechanisms occur 20 treatments. In general, research has indicated that max- in nature. Of particular interest is the synthesis of mag- imizing iron content and administering calcinations tem- netic particles approaching the 5 nm length scale. Mag- peratures in the range of 600-900°C lead to increasing netic particles can be used as markers for the detection amounts of maghemite, γ-Fe2O3, and yielded high mag- of biological molecules or in a drug delivery system to netic moments. Heretofore, conventional techniques for target infected biological tissues. The detection and tar- 25 making superparamagnetic particles have been limited geting may be monitored or controlled using the magnetic to the production of spherical particles. properties of the particles. In terms of medical needs, [0005] Sato et al (J Appl. Phys. (5),88 2771-2774 magnetic particles are used as directed delivery agents (2000); XP012051496) discloses superparamagnetic for radionuclides as a method of tumor treatment. Also, Co3O4 nanocrystals dispersed in an amorphous silicate magnetic particles can be utilized in sensor and separa- 30 by calcination of a molecular sieve soaked in 0.01 mol/l tion technology. For example, the surface of the magnetic CoCl2 aqueous solution. The molecular sieve was syn- particles could be functionalized with specific biomolecu- thesized by thermally dehydrating and then calcinating lar recognition sites, cells or proteins to detect antibodies in flowing oxygen a mixture of amorphous SiO 2, dodecylt- through separation of a fluidic medium using magnetic rimethylammonium chloride (C12H25N(CH3)3Cl), NaOH fields. 35 and water in the molar ratio 1.00:0.70:0.24:53.7. [0003] It is well known that superparamagnetic parti- [0006] Diamagnetic aluminosilicate mesostructures cles only exhibit magnetization in the presence of a mag- have been synthesized from block copolymer phases. In netic field. A superparamagnetic nanostructure having a particular Ulrich et al (Adv. Mat. 11(2), 141-146 (1999): well-controlled shape, size, and composition would be XP000877978) discloses nano-objects of controlled useful in the biological field, as well as many other fields. 40 shape, size and composition prepared by a sol- gel proc- Superparamagnetic nanostructures can be easily intro- ess of a mixture of 3-glycidyloxy-propyltrimethoxysilane duced into a biological fluid without the concerns of ag- and aluminum-sec-butoxide with poly(isoprene-block- glomeration due to ferromagnetic attraction that would polyethylene oxide). By increasing the fraction of inor- be present in other non- superparamagnetic particles and ganic precursors, 3-glycidyloxy-propyltrimethoxysilane nanostructures. Additionally, the presence and location 45 and aluminum-sec-butoxide, expected block copolymer of the superparamagnetic nanostructures can be detect- morphologies were exhibiting phase separation on the ed using a magnetic field. length scale of about 20 nm. Later studies extended this [0004] Iron silicates particles exhibit superparamag- approach to produce single nano-objects. The hy- netic properties below a critical size. Beginning in the drophilic part of the block copolymer was embedded in early 1980’s, the characterization of iron silicates provid- 50 the inorganic phase while the hydrophobic part forms the ed useful early information concerning iron species at second phase. Then an organic solvent dissolves the different calcinations temperatures and a limited study bulk materials leading to "hairy" objects. Upon heating at of magnetic properties. In addition, these earlier studies high temperatures (~600°C), aluminosilicate spheres, developed a synthesis strategy for producing bulk iron cylinders, and plates of controlled shape, size, and com- silicates whereby metal alkoxides, specifically iron tri- 55 position result. However, there have been no reports re- ethoxide and iron tripropoxide, were mixed with silicon lating to the production of superparamagnetic nanostruc- precursors, most commonly iron salts were used such tured material having these various shapes. In particu- as iron halides (FeCl 3) and organic salts like iron nitrate. larly, therehave been no reports relating to theproduction 3 3 EP 1 397 243 B1 4 of mesoporous nanostructures exhibiting superpara- precursor solution undergoes hydrolysis and condensa- magnetism. Mesoporous nanostructures would be viable tion to form a sol- gel precursor. In one preferred embod- structures in filtration processes and as a catalytic ma- iment, an aluminum-containing compound is mixed with terial. the silicate precursor solution. An iron precursor is added
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