Templated Synthesis of Highly Ordered Mesostructured Nanowires and Nanowire Arrays

One of the key challenges in nanotechnology is to control a self‐assembling system to create a specific structure. Self‐organizing block copolymers offer a rich variety of periodic nanoscale patterns, and researchers have succeeded in finding conditions that lead to very long range order of the domains. However, the array of microdomains typically still contains some uncontrolled defects and lacks global registration and orientation. Recent efforts in templated self‐assembly of block copolymers have demonstrated a promising route to control bottom‐up self‐organization processes through top‐down lithographic templates. The orientation and placement of block‐copolymer domains can be directed by topographically or chemically patterned templates. This templated self‐assembly method provides a path towards the rational design of hierarchical device structures with periodic features that cover several length scales.

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“…For example, the helices from cylinder-forming block copolymers confined inside tubular pores add chirality to the nanowire family. [132] …”

Section: Block Copolymers In Nonplanar Confinementmentioning

confidence: 99%

Templated Self‐Assembly of Block Copolymers: Top‐Down Helps Bottom‐Up

et al. 2006

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“…[11][12][13] Wu et al synthesized silica nanorods containing helical and circular-cylindrical ''stacked-doughnuts'' mesopore structures by gelation and calcination of sol-gels containing poly(ethylene oxide)-block-poly(propylene oxide)-block-poly(ethylene oxide) and tetraethyl orthosilicate infiltrated into AAO with pore diameters below 70 nm, [11] and prepared metal replicas of helical mesopores by electrochemical deposition. [14] However, only little effort has been directed to the experimental study of BCP melts selfassembling under strong cylindrical confinement, [12] even though the formation of a broad variety of unprecedented confinementinduced nanoscopic domain structures has been predicted. [15] Thus, only a small range of the potentially accessible morphologies has been realized, and their exploitation for the generation of functional nanostructures has not yet been addressed.…”

mentioning

confidence: 99%

Nanoscopic Morphologies in Block Copolymer Nanorods as Templates for Atomic‐Layer Deposition of Semiconductors

et al. 2009

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Block copolymers (BCPs) self-assemble into ordered arrays of nanoscopic domains, the nature of which depends on the constituents of the BCPs and their molecular architecture.[1] BCPs have been exploited as precursors for nanoporous materials [2] and as templates for the rational design of nanoscopic architectures with periods from below 10 nm up to the 100-nm-range in thin-film configurations.[3] Whereas molds containing arrays of aligned cylindrical nanochannels with hard confining walls, such as self-ordered anodic aluminum oxide (AAO), [4] have been used to fabricate one-dimensional nanostructures from a plethora of materials, [5] the self-assembly of BCPs in cylindrical confinement has only recently emerged as an access to nanorods exhibiting ordered nanoscopic fine structures.[6] Sol-gels containing precursors for inorganic scaffold materials and BCPs as structuredirecting soft templates were infiltrated into AAO. Subsequent gelation and calcination yielded nanorods consisting of various inorganic oxides and amorphous carbon exhibiting ordered mesoporous fine structures. [7] However, direct infiltration of microphase-separated BCP melts into AAO [8] has received much less attention, mainly because of a lack of obvious applications of the solid BCP nanorods thus obtained. Only recently, BCP nanorods have been converted into mesoporous polymeric nanorods by degrading sacrificial blocks [9] and by selective swelling.[10]BCPs confined to AAO with pore diameters about one order of magnitude larger than their characteristic bulk periods have been reported to retain bulk-like morphologies, such as cylinders oriented along the pore axes and concentric-cylindrical lamellae.Nanoscopic domain structures substantially different from those obtained in the absence of geometric constraints form if BCPs self-assemble within cylindrical pores having diameters of the same order of magnitude than their characteristic periods. [11][12][13] Wu et al. synthesized silica nanorods containing helical and circular-cylindrical ''stacked-doughnuts'' mesopore structures by gelation and calcination of sol-gels containing poly(ethylene oxide)-block-poly(propylene oxide)-block-poly(ethylene oxide) and tetraethyl orthosilicate infiltrated into AAO with pore diameters below 70 nm, [11] and prepared metal replicas of helical mesopores by electrochemical deposition.[14] However, only little effort has been directed to the experimental study of BCP melts selfassembling under strong cylindrical confinement, [12] even though the formation of a broad variety of unprecedented confinementinduced nanoscopic domain structures has been predicted. [15] Thus, only a small range of the potentially accessible morphologies has been realized, and their exploitation for the generation of functional nanostructures has not yet been addressed.Here, we report the fabrication of hierarchical one-dimensional semiconductor nanostructures containing structural motifs, such as helices and stacked doughnuts, that mimic unconventional, confinement-induced nanoscopic...

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“…Such nanostructures have a potential use for various sensors by utilizing their inherent optical and electrical properties of those nanostructures. 22,25,29,33,34 Although the hybrid mesoporous membrane with 1D silicananochannels can be applicable to various fields of analytical chemistry, several problems to be overcome still remain in order to develop innovative separation systems based on the hybrid mesoporous membranes.…”

Section: Analytical Applicationsmentioning

confidence: 99%

Fabrication and Analytical Applications of Hybrid Mesoporous Membranes

Yamaguchi

Teramae

2008

ANAL. SCI.

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Recently, a hybrid mesoporous membrane composed of surfactant-templated mesoporous silica inside a porous anodic alumina membrane has been developed. Since this membrane allows the use of columnar silica-mesopores (silicananochannels) as nanofluidic channels, separation of molecules can be realized by mass transport through the silicananochannel with molecular dimensions. Here, we review the methods to fabricate the hybrid mesoporous membranes, their structural features, and the analytical applications of hybrid mesoporous membranes.

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Templated Synthesis of Highly Ordered Mesostructured Nanowires and Nanowire Arrays

Cited by 204 publications

References 33 publications

Templated Self‐Assembly of Block Copolymers: Top‐Down Helps Bottom‐Up

Templated Self‐Assembly of Block Copolymers: Top‐Down Helps Bottom‐Up

Nanoscopic Morphologies in Block Copolymer Nanorods as Templates for Atomic‐Layer Deposition of Semiconductors

Fabrication and Analytical Applications of Hybrid Mesoporous Membranes

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