合成介孔材料-综述.pdf

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1、Registered Charity Number 207890Accepted ManuscriptThis is an Accepted Manuscript,which has been through the RSC Publishing peer review process and has been accepted for publication.Accepted Manuscripts are published online shortly after acceptance,which is prior to technical editing,formatting and

2、proof reading.This free service from RSC Publishing allows authors to make their results available to the community,in citable form,before publication of the edited article.This Accepted Manuscript will be replaced by the edited and formatted Advance Article as soon as this is available.To cite this

3、 manuscript please use its permanent Digital Object Identifier(DOI),which is identical for all formats of publication.More information about Accepted Manuscripts can be found in the Information for Authors.Please note that technical editing may introduce minor changes to the text and/or graphics con

4、tained in the manuscript submitted by the author(s)which may alter content,and that the standard Terms&Conditions and the ethical guidelines that apply to the journal are still applicable.In no event shall the RSC be held responsible for any errors or omissions in these Accepted Manuscript manuscrip

5、ts or any consequences arising from the use of any information contained in them.ChemCommwww.rsc.org/chemcommISSN 1359-7345Chemical Communicationswww.rsc.org/chemcommVolume 46|Number 32|28 August 2010|Pages 581359761359-7345(2010)46:32;1-HVolume 46|Number 32|2010 ChemComm Pages 58135976COMMUNICATION

6、J.Fraser Stoddart et al.Directed self-assembly of a ring-in-ring complexFEATURE ARTICLEWenbin Lin et al.Hybrid nanomaterials for biomedical applicationsChemical ScienceDownloaded by University of Science and Technology of China on 30 November 2012Published on 29 November 2012 on http:/pubs.rsc.org|d

7、oi:10.1039/C2CC36964HView Article Online/Journal HomepageJournal Name Cite this:DOI:10.1039/c0 xx00000 x www.rsc.org/xxxxxx Dynamic Article Links A ARTICLE TYPERTICLE TYPE This journal is The Royal Society of Chemistry year journal,year,vol,0000|1 An Overview of the Synthesis of Ordered Mesoporous M

8、aterials Wei Li and Dongyuan Zhao*Received(in XXX,XXX)Xth XXXXXXXXX 20XX,Accepted Xth XXXXXXXXX 20XX DOI:10.1039/b000000 x In this viewpoint,we focus on two highly-cited papers published in Chem.Commun.by Inagaki et al.in 5 1993 and Kleitz et al.in 2003,respectively,which are undoubted landmarks in

9、the development of ordered mesoporous materials.Here,we present an overview of their historical contributions in the synthesis and evolution of this field since its discovery,and the progress based on the achievements.Porous materials are of great interest because of their ability to interact with a

10、toms,ions,molecules and nanoparticles not only at 10 their surfaces,but throughout the bulk of the materials.1-3 Therefore,the presence of pores in nanostructured materials greatly promotes their physical and chemical properties.4 Recently,the well understanding,design,and manipulation of pores have

11、 significantly advanced science and technology,and 15 are playing increasingly important roles in modern society.According to the definition of the International Union of Pure and Applied Chemistry(IUPAC),porous materials can be classified into microporous(with pore diameter 50 nm),20 respectively.5

12、 Among them,microporous materials(zeolite molecular sieves)have been widely used in chemical and petrochemical industry processes.1-3 In the case of mesoporous materials,the structural capabilities at the scale of a few nanometers and high surface area can meet the demands of the 25 growing applicat

13、ions such as adsorption,separation,catalysis,drug delivery,sensors,photonics,energy storage and conversion,and nanodevices,especially for dealing with large molecules such as biomolecules and heavy oils.Zeolites or microporous materials are far away from these demands.1,2 These motivations 30 spark

14、the proliferation of mesoporous materials.Science 1980s,pillared clays containing mesopores have been well studied.2,6 However,their disordered rectangular pores could not be fully opened.Molecules could not easily pass through these pores,leading to coking in catalytic processes.Moreover,the pore s

15、izes 35 are widely distributed and difficult to control,and the arrangement of pores is disordered.2 Technical advances in the fields of chemistry,materials science,biology,and engineering,require the development of mesoporous materials with controllable structures and tuneable pore architecture.40

16、In 1992,Mobil scientists reported the synthesis of ordered mesoporous molecular sieves(M41S)from liquid-crystal templates.7 This is the first time that the term,“mesoporous molecular sieves”,appears in a publication paper,although“mesopore”is not a new term according to IUPAC definition and 45 a US

17、patent was firstly applied in Jan.1990.5,8 In fact,in the early time(1969),Vincent et al.had prepared MCM-41 analogues,but unfortunately they only claimed low-bulk density silica due to the lack of detailed characterizations.9 Another worth-mention is that in Apr.1990,Japanese scientists reported 50

18、 the synthesis of alkytrimethylammonium-kanemite complexes with a mixed phase.10 Although N2 sorption isotherms showed narrow pore size distribution at 2 4 nm for the products,the authors did not realize“mesopores”and“mesoporous molecular sieves”.In 1993,Inagaki,Fukushima and Kuroda optimized the 55

19、 synthesis condition and obtained a pure ordered mesoporous silicate.11 The results were published in Chem.Commun with the title of“Synthesis of Highly Ordered Mesoporous Materials from a Layered Polysilicate”.The main contribution described in this paper is the realization of the significance of a“

20、template”that has 60 been widely used in zeolite synthesis for preparing ordered mesoporous materials.1,2 They first reported the synthesis of ordered mesoporous silica with a pure hexagonal phase,which showed similar XRD patterns(Fig.1a)with MCM-41,and was different with the former results.7,10 In

21、addition,it is the first time 65 to simply prepare highly ordered mesoporous materials from the natural minerals.Later,the large domain regularity of the products(denoted as FSM-16)was verified by TEM images(Fig.1b and 1c),which was further elaborated by the authors.12 Significantly,at the low conce

22、ntration of surfactants,the 70 proposed pillared mechanism greatly enriches and expands the mechanism of“liquid crystal templating”(LCT).Since then,the soft-templating method has become a general pathway for the synthesis of ordered mesoporous materials,and the refinement of Fig 1.(a)XRD patterns of

23、 the as-made silicate-organic complex and calcined products at 700 and 1000 C,respectively,(b)TEM images of the as-made silicate-organic complex and calcined products at 550 C from the original Inagaki et al papers.Panel(a)and(b,c)are reproduced with permission from ref.11 and 12,respectively.Page 1

24、 of 3ChemCommChemical Communications Accepted ManuscriptDownloaded by University of Science and Technology of China on 30 November 2012Published on 29 November 2012 on http:/pubs.rsc.org|doi:10.1039/C2CC36964HView Article Online 2|Journal Name,year,vol,0000 This journal is The Royal Society of Chemi

25、stry year this method via two synthetic strategies(cooperative self-assembly and“true”liquid-crystal templating process)was soon reported(Fig.2).2,13 In the cooperative self-assembly process,inorganic species interact with surfactants driven by Coulomb force or hydrogen bonding.The inorganic species

26、 at the interface 5 polymerize and cross-link,and thus cooperatively assemble with surfactants.With the reaction,the cooperative arrangements of surfactants and the charge density between inorganic and organic species influence each other.Hence the compositions of inorganicorganic hybrids differ to

27、some degree.The matching of 10 charge density at the surfactant/inorganic interfaces governs the assembly process,thus resulting in phase separation and reorganization,finally leading to the formation of ordered 3-D arrangement with the lowest energy.The“true”liquid-crystal templating process is bas

28、ed on true or semi-liquid-crystal 15 mesophase micelles produced by high-concentration surfactants as templates.The condensation of inorganic precursors is improved by reaction of the confined growth around surfactants,forming ceramic-like frameworks.After condensation,the organic templates can be r

29、emoved.The inorganic materials 20“nanocast”the mesostructures,pore sizes,and symmetries from the liquid-crystal scaffolds.Using this soft-templating method,numerous novel ordered mesoporous materials composed of inorganic,organic,and inorganic-organic composite frameworks have been prepared via vari

30、ous synthetic methods such as 25 aqueous processes,nonaqueous approach which is also well-known as evaporation induced self-assembly(EISA)process,hydrothermal method,etc.2,14,15 Plenty of soft templates,including cationic,anionic and non-ionic surfactants,and mixed surfactant systems,have been utili

31、zed to synthesize ordered 30 mesoporous materials with controllable structures and tuneable pore architecture.2 Of particular mention was the remarkable findings by Zhao et al.regarding the preparation of large-pore ordered mesoporous silica with a 2D hexagonal structure by using triblock copolymers

32、 as templates,which is very famous 35 known as SBA-15.16 In 1998,Yang et al.first used block copolymers as structure-directing agents to prepare various ordered mesoporous metal oxides through a EISA process.17 Another well-worth mention was the great achievement illustrated by the Ryoo group,Korea,

33、which was also published in 40 Chem.Common.in 2003,appeared under the title of“Cubic Ia3d large mesoporous silica:synthesis and replication to platinum nanowires,carbon nanorods and carbon nanotubes”.18 In this article,they reported the synthesis of large-pore ordered cubic(Ia3d)45 mesoporous silica

34、(known as KIT-6,Fig.3a and 3c).19,20 Although,Liu et al.first reported the synthesis of large-pore 3D bicontinuous mesoporous silica by using a commercial triblock copolymer as a template,the quick self-50 assembled approach in the EISA process produce a plenty of defects in the resultant ordered me

35、sostructures,leading to low-quality XRD patterns.21 Here,butanol was first employed to tailor the mesophase of block 55 copolymers micelles in aqueous phase because it can swell the hydrophobic chains and thus decrease the curvature,leading to the mesophase change from hexagonal to cubic phase.The h

36、igh-quality XRD patterns clearly illustrated the 60 perfect mesostructures,which is the appealing bicontinuous helix channel structure and very rare in nature.Despite the great success of the soft-templating method,it was soon realised that it was not sufficient enough to prepare many non-siliceous

37、mesostructured materials because the non-siliceous 65 precursors are more susceptible to hydrolysis,lack of condensation,redox reactions,weak connection with surfactants or phase transitions accompanied by thermal breakdown of the structural integrity,which make it much more difficult to construct o

38、rdered mesostructures and remove the templates.22-23 70 Significantly,in this context,Ryoo and coworkers employed the resultant KIT-6 as a hard template for the synthesis of ordered mesoporous materials via three steps:i)precursor infiltration inside mesochannels of the silica template;ii)conversion

39、 of the precursor in the nanochannels;iii)removal of mesoporous silica 75 template,which is well-known as nanocasting because the entire manufacturing procedure is similar with the traditional casting Fig 3.XRD patterns(a,b)and TEM images(c,d)of the ordered cubic Ia3d mesoporous silica(KIT-6)and ord

40、ered mesoporous carbons from KIT-6,respectively.The insets in(a)and(b)are the corresponding structure modes.Panels(a,b)and(c,d)are reproduced with permission from ref.18,20 and 19,25 respectively.Fig 2.Schematic representation of the soft-templating method via two synthetic strategies:A)cooperative

41、self-assembly and B)“true”liquid-crystal templating process for the synthesis of ordered mesoporous materials.Reproduced with permission from ref.3.Page 2 of 3ChemCommChemical Communications Accepted ManuscriptDownloaded by University of Science and Technology of China on 30 November 2012Published o

42、n 29 November 2012 on http:/pubs.rsc.org|doi:10.1039/C2CC36964HView Article Online This journal is The Royal Society of Chemistry year Journal Name,year,vol,0000|3 method but in the nanoscale(Fig.4).13,22-24 The high-quality XRD pattern and TEM image(Fig.3b and 3d)18-19 of the resulted mesoporous ca

43、rbons clearly announced the feasiblity of this nanocasting strategy and the novel“hard template”concept for preparing mesoporous materials,which since became a hot topic 5 in the research field of ordered mesostructured materials,especially for those unavailable via the soft-templating method.In thi

44、s nanocasting approach(Fig.4),the regular arrangement comes from the preformed ordered mesoporous template.It should be mentioned that the small mesotunnels inside the 10 templates pore walls are necessary for nanocasting.They can be replicated to small nanorods,which thus support the nanowire/nanop

45、ipes replicated from the primary mesopores,to form stable mesostructured replica arrays.Otherwise,the obtained replicas cannot maintain their mesostructures once the 15 templates are removed,resulting in isolated nanowires/nanopipes or low-symmetry mesostructured products.Moreover,the resultant meso

46、structured replica arrays can also be used as a new hard template for ordered mesoporous materials.It should be noted that the earliest example could be traced back to 1999 also 20 reported by the Ryoo group using MCM-48 templates,26 however,the symmetry of the resulted negative replica was reduced.

47、In contrast,using the KIT-6 as a hard template,ordered mesoporous carbons with the same Ia3d symmetry were synthesized.That is because the KIT-6 possesses plentiful micropores connecting the 25 two enantiomeric pore systems,which would be replicated to small nanorods and thus support the ordered mes

48、ostructures of replicas.Therefore,KIT-6 is a best choice for a hard template candidate just like SBA-15 but to synthesize cubic mesoporous materials.Since then,various highly ordered mesoporous oxides 30 or non-oxides,especially with high crystalline or even single crystal frameworks,are well develo

49、ped by using KIT-6 silicas as the templates via the nanocasting process.13,22-24 Conclusions The work by Inagaki et al.in 1993 was nevertheless not the 35 first paper claiming the synthesis of ordered mesoporous materials,but it undoubtedly constituted a breakthrough because of the first realization

50、 of the significance of a“template”concept from zeolites to ordered mesoporous materials synthesis and the pure ordered mesophase from the natural minerals,which was 40 rarely reported before.At the low concentration of surfactants,the proposed pillared mechanism greatly enriches and expands the mec