共查询到20条相似文献，搜索用时 15 毫秒
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Li‐Chen Cheng John W. Simonaitis Karim R. Gadelrab Mukarram Tahir Yi Ding Alfredo Alexander‐Katz Caroline A. Ross 《Small (Weinheim an der Bergstrasse, Germany)》2020,16(1)
A robust and transparent silica‐like coating that imparts superhydrophobicity to a surface through its hierarchical multilevel self‐assembled structure is demonstrated. This approach involves iterative steps of spin‐coating, annealing, and etching of polystyrene‐block‐polydimethylsiloxane block copolymer thin films to form a tailored multilayer nanoscale topographic pattern with a water contact angle up to 155°. A model based on the hierarchical topography is developed to calculate the wetting angle and optimize the superhydrophobicity, in agreement with the experimental trends, and explaining superhydrophobicity arising through the combination of roughness at different lengthscales. Additionally, the mechanical robustness and optically passive properties of the resulting hydrophobic surfaces are demonstrated. 相似文献
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Xiangxing Xu Xun Wang Amjad Nisar Xin Liang Jing Zhuang Shi Hu Yuan Zhuang 《Advanced materials (Deerfield Beach, Fla.)》2008,20(19):3702-3708
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Block copolymer (BCP) self‐assembly (SA) can be exploited for next‐generation lithography for the advanced nanopatterning of surfaces with versatile nanoscale features. To render BCP‐SA suitable for the creation of tailored surface patterns, a fundamental understanding of interfacial interactions is crucial. This progress report gives an overview on the interplay of BCP microscale film thickness modulation and nanoscale microphase separation during BCP‐SA. Light is shed on the role of interfacial energies in both events. Microscale processes determining the topography of BCP films, i.e., hole/island formation and dewetting into droplets, are presented. Nanoscale microphase separation into energetically favorable pattern orientations in dependency on the polymer film thickness and influenced by surface polarities are discussed critically. Finally, examples are shown in which the combination of microscale dewetting and nanoscale microphase separation are exploited to create hierarchical nanostructures from BCPs. An outlook is given presenting successful applications of both mechanisms on prepatterned surfaces in order to control position and morphology of the hierarchical nanostructures. This approach is particularly promising for the creation of advanced surface architectures. 相似文献
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Katharina Brassat Daniel Kool Colin G. A. Nallet Jrg K. N. Lindner 《Advanced Materials Interfaces》2020,7(1)
Block copolymer (BCP) lithography is a versatile bottom‐up approach for the creation of regular nanoscale patterns on large surface areas. The pattern morphology evolving during the microphase separation of a BCP is strongly dependent on the polymer film thickness. Thus, surface wetting as well as interfacial energies between polymer and substrate determine the polymer behavior, however, the complex interplay of those effects is not yet fully understood. In this work, a model describing the film thickness dependence of BCP self‐assembly on prepatterned surfaces is proposed. Polymer dewetting on nanohole‐patterned surfaces is controlled using different prepattern dimensions, polymer amounts, and microphase‐separation temperatures. This is found to allow for a precise local film thickness modulation and thus allows to guide BCP self‐assembly into arrays of tailored hierarchical nanoarchitectures. Analytical calculations of the total surface free energies of the microphase‐separated polymer of different film thicknesses confined inside nanoholes confirm the model. The insights contribute to the understanding of fundamental processes in polymer dewetting and BCP self‐assembly and allow for the controlled creation of advanced hierarchical nanostructures on large areas for applications in optics, plasmonics, and biomedical devices. 相似文献
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Bong Hoon Kim Kyeong‐Jae Byeon Ju Young Kim Jinseung Kim Hyeong Min Jin Joong‐Yeon Cho Seong‐Jun Jeong Jonghwa Shin Heon Lee Sang Ouk Kim 《Small (Weinheim an der Bergstrasse, Germany)》2014,10(20):4207-4212
Negative‐tone block copolymer (BCP) lithography based on in situ surface chemical modification is introduced as a highly efficient, versatile self‐assembled nanopatterning. BCP blends films consisting of end‐functionalized low molecular weight poly(styrene‐ran‐methyl methacrylate) and polystyrene‐block‐Poly(methyl methacylate) can produce surface vertical BCP nanodomains on various substrates without prior surface chemical treatment. Simple oxygen plasma treatment is employed to activate surface functional group formation at various substrates, where the end‐functionalized polymers can be covalently bonded during the thermal annealing of BCP thin films. The covalently bonded brush layer mediates neutral interfacial condition for vertical BCP nanodomain alignment. This straightforward approach for high aspect ratio, vertical self‐assembled nanodomain formation facilitates single step, site‐specific BCP nanopatterning widely useful for various substrates. Moreover, this approach is compatible with directed self‐assembly approaches to produce device oriented laterally ordered nanopatterns. 相似文献
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Jeong Ho Mun Seung Keun Cha Ye Chan Kim Taeyeong Yun Young Joo Choi Hyeong Min Jin Jae Eun Lee Hyun Uk Jeon So Youn Kim Sang Ouk Kim 《Small (Weinheim an der Bergstrasse, Germany)》2017,13(17)
Spatial arrangement of 1D nanomaterials may offer enormous opportunities for advanced electronics and photonics. Moreover, morphological complexity and chemical diversity in the nanoscale components may lead to unique properties that are hardly anticipated in randomly distributed homogeneous nanostructures. Here, controlled chemical segmentation of metal nanowire arrays using block copolymer lithography and subsequent reversible metal ion loading are demonstrated. To impose chemical heterogeneity in the nanowires generated by block copolymer lithography, reversible ion loading method highly specific for one particular polymer block is introduced. Reversibility of the metal ion loading enables area‐selective localized replacement of metal ions in the self‐assembled patterns and creates segmented metal nanowire arrays with different metallic components. Further integration of this method with shear aligning process produces high aligned segmented metal nanowire array with desired local chemical compositions. 相似文献
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The self‐assembly of block copolymers in thin films provides an attractive approach to patterning 5–100 nm structures. Cross‐linking and photopatterning of the self‐assembled block copolymer morphologies provide further opportunities to structure such materials for lithographic applications, and to also enhance the thermal, chemical, or mechanical stability of such nanostructures to achieve robust templates for subsequent fabrication processes. Here, model lamellar‐forming diblock copolymers of polystyrene and poly(methyl methacrylate) with an epoxide functionality are synthesized by atom transfer radical polymerization. We demonstrate that self‐assembly and cross‐linking of the reactive block copolymer materials in thin films can be decoupled into distinct, controlled process steps using solvent annealing and thermal treatment/ultraviolet exposure, respectively. Conventional optical lithography approaches can also be applied to the cross‐linkable block copolymer materials in thin films and enable simultaneous structure formation across scales—micrometer scale patterns achieved by photolithography and nanostructures via self‐assembly of the block copolymer. Such materials and processes are thus shown to be capable of self‐assembling distinct block copolymers (e.g., lamellae of significantly different periodicity) in adjacent regions of a continuous thin film. 相似文献
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Yushu Matsushita Atsushi Takano Marylne Vayer Christophe Sinturel 《Advanced Materials Interfaces》2020,7(5)
During the self‐assembly process of block copolymers, interfaces are formed as a result of the microphase separation between the blocks. The location of the polymer chains and block junctions with respect to these interfaces is crucial and drives the morphology. It depends on the dispersities (e.g., molecular mass and composition) of the blocks, their architectures (e.g., linear vs star), and the type of interaction (e.g., repulsion vs attraction). In this review, the authors focus on the formation of unusual morphologies that are obtained in the following three categories: i) multimodal blends of block polymers, ii) star block polymers, and iii) supramolecular assemblies composed of block copolymers. Although these three examples seem to be very different from one another, the authors demonstrate in this review that they all share a constrained location of their chains and/or junctions with respect to the interfaces. In this sense, they deviate from the common behavior of simple linear block copolymers, in which the junctions are located on the interface and homogeneously distributed onto it. 相似文献
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