Download or read book Directed Assembly of Block Copolymers Using Chemically and Topographically Patterned Substrates to Control and Direct the Order of Various Nanodomains written by Sang-Min Park, 1974- and published by . This book was released on 2007 with total page 210 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Directed Self assembly of Block Copolymer Films on Chemically Nanopatterned Surfaces written by Adam M. Welander and published by . This book was released on 2009 with total page 118 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Directed Self assembly of Diblock Copolymer Thin Films on Chemically Nanopatterned Substrates written by Erik WiIliam Edwards and published by . This book was released on 2005 with total page 248 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Directed Self assembly of Block Copolymers and Ternary Block Copolymer homopolymer Blends on Chemically Patterned Surfaces Into Device oriented Geometries written by Mark P. Stoykovich and published by . This book was released on 2007 with total page 210 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Self assembly of Block Copolymers for Nanopatterning written by Nathanael Lap-Yan Wu and published by . This book was released on 2014 with total page 185 pages. Available in PDF, EPUB and Kindle. Book excerpt: The impressive developments in the semiconductor industry over the past five decades have largely been dependent on the ability to continually reduce the dimensions of devices on a chip. However, as critical dimension requirements for these devices approach the limits of photolithography, new fabrication strategies must be introduced for these remarkable advances to continue. One technology listed by the International Technology Roadmap for Semiconductors as a candidate for next-generation nanostructure fabrication is the directed self-assembly of block copolymers. Block copolymers have received significant attention of late for their ability to template large regular arrays of nanostructures with dimensions ranging from 10 to 50 nm. The production of denser sub-10 nm nanostructures is also possible by reducing the size of these polymers, but a reduction of the polymer size also compromises the quality of nanostructures, making small polymers extremely difficult to use. In this thesis, two different patterning approaches are introduced to push the nanostructure density limits possible for a given polymer. In the first, a novel patterning approach involving thin films of bilayer block copolymer domains is used to effectively double the nanostructure density patterned by a given polymer. The technique is successfully applied to different types and sizes of polymer, and can also form highly controlled arrays of patterns with the help of surface topography. By varying different process parameters during the self-assembly or subsequent plasma steps, the dimensions of these density-doubled patterns may be finely-tuned to the desired width and pitch. The surface coverage of these density-doubled nanostructures is also maximized through adjusting the film thickness and parameters in the self-assembly process. Besides using bilayer films, dense arrays of nanostructures may also be patterned using a multi-step patterning approach. In this approach, multiple layers of block copolymer films are subsequently deposited onto the substrate to template nanostructures. Because nanostructures from previous layers contribute to the surface topography, they influence the self-assembly of successive layers and more dense and complex patterns may be produced as a result.

Download or read book Directed Assembly of Block Copolymer Films Via Surface Energy Tunable Elastomers written by Arzu Hayirlioglu and published by . This book was released on 2014 with total page 138 pages. Available in PDF, EPUB and Kindle. Book excerpt: Ordering of block copolymer (BCP) thin films has been great interest for potential applications due to nanometer scale size self-assembly pattern formation. Numerous methods (chemical, physical, etc.) have been developed to create desired alignment and ordering properties in such block copolymer systems. However, the drawback of most current technologies such as brittleness and lack conformability to different surfaces makes them difficult to implement new emerging high-tech flexible technologies. On the other hand, there is a lack of knowledge in block copolymer wettability characteristics and morphological behavior on soft substrates which makes them attractive to explore for further investigations. A notable challenge in this regard is that successful deployment of BCPs for applications requires an understanding of BCP ordering properties on flexible substrate as a function of their surface chemistry, topography including patterning, roughness, stiffness, modulus and thermal conductivity, etc. Therefore, the general purpose of this research is to investigate the thermodynamics and kinetics of directed assembly of cylinder and lamellar forming polystyrene-block-polymethlymethacrylate (PS-b-PMMA) diblock copolymer films on elastomeric polydimethylsiloxane (PDMS) substrates with controlled surface energy and substrate topography. In first part, wettability characteristics of cylinder and lamellae forming PS-b-PMMA thin films versus surface energy of elastomeric PDMS substrates were increasing surface energy of PDMS by tuning with Ultraviolet Ozone (UVO) exposure and elasticity by varying the crosslinking concentration. In this extended wetting regime gradual perpendicular to parallel orientation change was shown for lamellar BCP films unlike cylindrical films where the transition was very sharp, reflecting lamellar BCP intrinsic stability over a wider range of substrate surface energy, consistent with theoretical estimates. In second part of the study, we extended the part on wettability characteristics of polystyrene (PS) homopolymer and PS-b-PMMA block copolymer thin films on flat, periodic and non-periodic nanopatterned elastomeric PDMS substrates. We discovered creating non-periodically nanopatterned surface properties induced retardation of BCP dewetting and mostly eliminate on periodically nanopatterned surface properties without any surface chemistry modification. Time kinetic study results also showed the patterning has a slowing down effect on dewetting mechanism for both homopolymer and block copolymer systems and dewetted droplet shape. In final part of this study, we focused on block copolymer morphology on periodically and non-periodically (rough) patterned elastomeric PDMS substrates with and without tuning the substrate surface energy via UVO exposure. The regular uniform film properties were achieved with parallel or perpendicular microdomain orientation to the substrate at even imcommensurate thicknesses which normally shows island and holes on flat surfaces. In addition to the bottom pattern confinement effect on BCP ordering, uniform size patterned elastomeric top capping layer was also used. Mixed or long range ordered structures were obtained with different annealing conditions.

Download or read book Directed Self assembly of Block Copolymers on Chemically Nano patterned Surfaces written by Laura Evangelio Araujo and published by . This book was released on 2017 with total page 247 pages. Available in PDF, EPUB and Kindle. Book excerpt: La tesi doctoral titulada "Auto-assemblatge de copolímers de bloc per modificació química de la superfície", presenta com a objectiu principal el desenvolupament, implementació i caracterització d'un mètode de guiatge de copolímers de bloc basat en la modificació química de la superfície. El desenvolupament d'aquest mètode de nanofabricació contribueix a la futura generació de dispositius i circuits nanoelectrònics. Primer de tot, es presenten els aspectes generals sobre l'auto-assemblatge dirigit de copolímers de bloc, així com el seu rol dins del futur de la nanoelectrònica comparat amb altres tecnologies emergents. Després, per tal d'entendre i determinar les interaccions que tenen lloc durant el procés d'auto-assemblatge, es dóna una visió general sobre els processos químics i físics que tenen lloc en les pel·lícules primes de copolímers de bloc. La part principal de la tesi es focalitza en l'estudi, desenvolupament i implementació d'un mètode de guiatge químic per tal de dirigir l'auto-assemblatge de copolímers de bloc. A banda d'estudiar el procés experimental, també es caracteritzen els mecanismes que condueixen l'alineament i s'introdueixen a un model per simular el procés d'auto-assemblatge dirigit. A més, també es presenta la transferència del procés a una línia pilot industrial de fabricació de circuits integrats. La implementació del procés de guiatge químic s'ha provat no únicament amb materials comercials, sinó també amb nous sistemes polimèrics que permeten arribar a mides per sota dels 10 nm. Per aquests sistemes, es defineix un nou mètode de guiatge basat en la combinació de modificacions topogràfiques i químiques. Per tal d'entendre millor el procés, s'estudien tècniques específiques de metrologia. En particular, mitjançant tècniques d'alta energia de rajos X, es descriuen les principals diferències entre patrons químics de guiatge. D'altra banda, les propietats nanomecàniques dels diferents dominis del copolímer es determinen mitjançant el mode peak force tapping de la microscòpia de força atòmica. Finalment, es mostra un mètode per transferir els motius del copolímer al substrat. Aquest es basa en la infiltració d'un domini del copolímer. La infiltració canvia les propietats del material i el fa més resistiu al gravat amb oxigen. D'altra banda, i com a aplicació final, es presenta un procés de fabricació de ressonadors nanomecànics, basats en el procés d'auto-assemblatge de copolímers de bloc amb infiltració.

Download or read book Selective Directed Self assembly of Coexisting Morphologies Using Block Copolymer Blends written by and published by . This book was released on 2016 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Directed self-assembly (DSA) of block copolymers is an emergent technique for nano-lithography, but is limited in the range of structures possible in a single fabrication step. We expand on traditional DSA chemical patterning. Moreover, a blend of lamellar- and cylinder-forming block copolymers assembles on specially designed surface chemical line gratings, leading to the simultaneous formation of coexisting ordered morphologies in separate areas of the substrate. The competing energetics of polymer chain distortions and chemical mismatch with the substrate grating bias the system towards either line/space or dot array patterns, depending on the pitch and linewidth of the prepattern. This contrasts with typical DSA, wherein assembly of a single-component block copolymer on chemical templates generates patterns of either lines/spaces (lamellar) or hexagonal dot arrays (cylinders). In our approach, the chemical template encodes desired local spatial arrangements of coexisting design motifs, self-assembled from a single, sophisticated resist.

Download or read book Block Copolymer Self assembly written by Gayashani Kanchana Ginige and published by . This book was released on 2022 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Molecular self-assembly is the basis of structure in nature. While of far less complexity than a natural system, the same physical rules apply to simple synthetic designed systems that spontaneously form self-assembled structures and patterns. The self-assembly of block copolymers (BCPs) is an interesting example, as it can be harnessed to form both 2D (in thin films) and 3D (in bulk) porous and chemically controlled morphologies at scale. The self-assembly of BCPs on surfaces is of interest for a range of applications, but due to the enormous economic driver that is the computer industry, this direction has been pushed most strongly. Self-assembly of BCPs has been described in the International Technology Roadmap for Semiconductors (the ITRS, and now the IDRS) for almost two decades for lithography on semiconductors and for patterning the magnetic material of hard drives. As a result, there has been much academic interest, both fundamental and applied, to meet the challenges as outlined in the ITRS/IDRS due to the promise of this scalable and low-cost nanopatterning approach. More recently, the remarkable work harnessing BCP self-assembly has been directed to other applications, one being optical metamaterials; this thesis will add to this growing body of science. One aspect holding BCP self-assembly back is the defectivity in the patterned material or surface; some applications are more defect tolerant than others, but hard drive and other computer-industry applications have very low tolerance for defects. It is, therefore, important to have systematic control over the self-assembly process as well as quality of the final patterns generated by BCP self-assembly for these applications and others not yet imagined. This thesis examines the defectivity of the hexagonal nanoscale patterns derived from BCP self-assembly and looks at extending them to produce nanoscale patterns of native and non-native morphologies that have plasmonic properties. This thesis is divided into two parts. The first part deals with optimization of solvent vapor annealing of BCP self-assembly, the critical step in which the actual nanoscale phase segregation takes place; in this case, it uses a controlled solvent vapor flow annealing apparatus, design of experiment and machine learning approaches. In this work, it was discovered that slight variations in the initial film thickness on the order of even a couple of nanometers and the final swelling degree have a huge influence on the defectivity and the quality of the resulting patterns. Next, machine learning approaches are applied to compile qualitative and quantitative defect analysis into a single figure of merit that is mapped across an experimental parameter space. This approach enables faster convergence of results to arrive at the optimum annealing conditions for the annealing of thin films of BCPs of PS-b-PDMS that generate nanoscale hexagonal patterns of silica dots with a minimum number of defects. In the second part of the thesis, mixed metal/oxide double layer patterning was studied using sequential self-assembly of BCPs. The second part of the thesis starts with optimization of reactive ion etching (RIE) for producing single layer metal nanopatterns from metal ion-loaded thin films of PS-b-P2VP BCPs to generate single layers of hexagonal metal nanopatterns that can withstand a second consecutive reactive ion etching step. The goal of this work is to enable density doubled and/or Moiré pattern formation via self-assembly of a second layer of BCP on the initial pattern prepared by self assembly of either the same or different BCP, as will be described in Chapter 4. Therefore, the initial pattern produced via BCP self-assembly and RIE etching would need to withstand a second treatment step of BCP self-assembly and RIE. While single layer nanopatterns of Au and Pt nanoparticles can be produced without much trouble, these resulting patterns could not be applied for density multiplication of metal-metal nanopatterns since the metal dots become too small and disordered. To demonstrate that metal nanoparticles derived from BCPs could be used, at least, to produce a mixed metal oxide/metal patterns, arrays of SiOx dots were first produced from PS-b-PDMS BCPs and then layered a BCP of PS-b-P2VP that was subsequently loaded with gold or platinum ions. Upon RIE etching, the BCP is removed and the SiOx/Au or Pt nanoparticle arrays were produced. Based upon the outcomes of the optimization of the etching work, mixed Au-Pt commensurate and incommensurate hexagonal lattice patterns were produced on both silicon and quartz substrates. Finally, the optical properties of these mixed metal Pt-Au bilayer patterns were studied. They demonstrated interesting plasmonic properties of the bilayer patterns, including consistent observation of extended plasmon bands that suggest coupling of the localized surface plasmon resonances (LSPRs) of the gold nanoparticles through proximal platinum nanoparticles when arrayed in periodic patterns.

Download or read book Block Copolymer Self assembly as a Template for the Generation of Ordered Arrays of Nanowires written by Thomas Garrett Fitzgerald and published by . This book was released on 2008 with total page 214 pages. Available in PDF, EPUB and Kindle. Book excerpt: Upon self-assembly block copolymers (BCP) form a variety of well-ordered nanometer-sized structures in thin films which satisfy the size requirement for many nanotechnologies. This thesis details the in-depth study of three different BCP systems including the various factors which influence the final film structure, the generation of nanoporous polymer templates and their subsequent use a lithographic etch masks. Chapter 1 provides a general introduction to the principles of BCP self-assembly as well as a brief overview of the current state of this continually expanding field. Chapter 2 focuses on microphase separation within cylinder-forming polystyrene-block-polyisoprene-block-polystyrene BCP thin films. Thermal and solvent annealing are both investigated as potential routes to achieve microphase separation. Following a thermal anneal approach ordered cylindrical structures exhibiting excellent long-range order are achieved using directing effects imposed topographically channelled substrates. Control of film thickness within the channelled structures provides a simple method for control of cylinder orientation (parallel or perpendicular). In Chapter 3 macrophase separation is demonstrated in blends of polystyrene and poly(methyl metacrylate) illustrating the importance of the bonding between polymer units in a polystyrene-block-poly(methyl metacrylate) BCP as a requisite for microphase separation. Both cylinder- and lamellar-forming systems are demonstrated with this BCP, depending on the polymer ratio, and the orientation of the structures can be controlled via polymer-substrate interactions. Variation of molecular weight of the BCP provides a simple means of controlling resultant feature sizes. Reactive ion etching provides a rapid route for the generation of polystyrene template structures which can be subsequently used as positive etch mask to produce arrays of silicon lines. The microphase separation within both polystyrene-block-poly(ethylene oxide) BCP and polystyrene-block-poly(ethylene oxide)/polystyrene blend thin films, induced via solvent annealing, is discussed in Chapter 4. Blends of polystyrene homopolymer and polystyrene-block-poly(ethylene oxide) BCP result in a cylindrical structure rather than the predicted lamellar morphology due to the increased amount of polystyrene present. Selection of the appropriate solvent anneal conditions provides a simple means of controlling the orientation of the final structure. Variation of molecular weight again provides excellent control over feature size, however, if it is too low microphase separation will not occur. Reactive ion etching also provides a rapid route for the generation of polystyrene template structures. Chapter 5 provides a general overview of the various techniques used during the course of this thesis as well as providing supplementary information on calculations and BCP synthesis mentioned in previous chapters.

Download or read book Block Copolymers in Nanoscience written by Massimo Lazzari and published by Wiley-VCH. This book was released on 2007-06-27 with total page 447 pages. Available in PDF, EPUB and Kindle. Book excerpt: This first book to take a detailed look at one of the key focal points where nanotechnology and polymers meet provides both an introductory view for beginners as well as in-depth knowledge for specialists in the various research areas involved. It investigates all types of application for block copolymers: as tools for fabricating other nanomaterials, as structural components in hybrid materials and nanocomposites, and as functional materials. The multidisciplinary approach covers all stages from chemical synthesis and characterization, presenting applications from physics and chemistry to biology and medicine, such as micro- and nanolithography, membranes, optical labeling, drug delivery, as well as sensory and analytical uses.

Download or read book Templated Self assembly of Novel Block Copolymers written by Li-Chen Cheng (Ph.D.) and published by . This book was released on 2019 with total page 188 pages. Available in PDF, EPUB and Kindle. Book excerpt: Self-assembly of block copolymers (BCPs) is emerging as a promising route for numerous technological applications to fabricate a variety of nanoscopic structures. The resulting feature sizes range from a few to several hundred nanometers, and are readily tunable by varying the molecular weights of block copolymers. Directed self-assembly of block copolymer is an effective way to pattern periodic arrays of features with long-range order, to generate complex patterns, and to multiplicatively increase the pattern density and resolution that are far beyond the limit of conventional lithography. Despite of the significant progress in the area of directed self-assembly in recent years, critical research problems regarding the dimension scalability toward sub-10-nm regime and large feature sizes on hundreds of nanometers scale as well as the capability of generating complex device-oriented patterns remain challenging. In this thesis, BCP systems, including high-v BCPs that are capable of self-assembling into extreme small and large feature sizes as well as those with more complex block architectures, are identified and studied in order to understand how those materials may be processed and directed selfassembly to bridge the patterning size spectrum between nano- and micro-fabrication. Another focus is placed on the scientific exploration of directed self-assembly of triblock terpolymers and the investigation on the mechanisms that regulate the scaling and geometry of self-assembled patterns. A comprehensive understanding about self-assembly of BCP thin films will enable developing device-oriented geometries, manipulating BCPs phase behavior, and incorporating new functional materials for a wider range of applications. In the meanwhile, optimizing the processing condition of self-assembly of various BCPs is essential to confirm viability of the directed self-assembly of block copolymers process in manufacturing.

Download or read book Self assembly of Block Copolymers on Topographically Patterned Polymeric Substrates written by and published by . This book was released on 2016 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Highly-ordered block copolymer films are prepared by a method that includes forming a polymeric replica of a topographically patterned crystalline surface, forming a block copolymer film on the topographically patterned surface of the polymeric replica, and annealing the block copolymer film. The resulting structures can be used in a variety of different applications, including the fabrication of high density data storage media. The ability to use flexible polymers to form the polymeric replica facilitates industrial-scale processes utilizing the highly-ordered block copolymer films.

Download or read book The Self assembly of Lamellae forming Block Copolymer for High Resolution Nanolithography written by Zhiwei Sun and published by . This book was released on 2017 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis will be focused on the thin film self-assembly and high resolution nanolithography of lamellae-forming PS-b-P2VP block copolymer. Some of the scientific and engineering problems of block copolymer self-assembly will be studied using the state-of-the-art characterization facilities including AFM, SEM and synchrotron radiation X-ray scattering, pushing forward the application of block copolymer in high resolution nanolithography, storage media, and separation membranes, etc. The first challenge is the design of BCP with small domain spacing, which defines the resolution of BCP nanolithography. Small domain spacing can be achieved by reducing the degree of polymerization, but order-to-disorder transition happens when the critical [chi]N is reached. In this thesis, we will first discuss the disorder-to-order transition of low molecular weight PS-b-P2VP by increasing the [chi] parameter using salt doping. The domain spacing of PS-b-P2VP will be pushed down one step further by design BCPs with star shape chain architecture, achieving lamellar nanostructures with sub-10 nm repeating period. Another challenge that hampers the application of BCP is the defect in the self-assembled BCP thin film. The defects in the thin film reduces the grain sizes of BCP lattices and also brings in new challenges in lithography and pattern transfer, thus the defect density in the self-assembled BCP thin film has to be reduced. It is important to understand how the defects were generated and how it can be removed using annealing and directed self-assembly (DSA). In this thesis, in situ grazing incidence small angle X-ray scattering will be used to characterize the solvent vapor annealing of P2VP-b-PS-b-P2VP triblock copolymer in thin film. The trade-off between the in-plane and out-of-plane defect density was revealed during solvent evaporation. Furthermore, long-range ordered lamellar line patterns were prepared using directed self-assembly on patterned substrate.

Download or read book Solvent Vapor Assisted Self Assembly of Patternable Block Copolymers written by Joan K. Bosworth and published by . This book was released on 2009 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Block copolymer self assembly presents a method for patterning and templating applications on the 10-50 nm length scale, a smaller scale than can be easily achieved by photolithography. Here we investigate the use of functionalized polar-nonpolar block copolymers both as photopatternable self-assembling materials and for selective infiltration of one block for patterning. Block copolymer thin films with defect-free self-assembled morphology over large domains combined with careful control of the orientation of the morphology are critical for these patterning applications. Self assembly of block copolymers is facilitated by polymer chain mobility, commonly achieved by heating block copolymer films above the glass transition temperature of the blocks. However, many block copolymer systems, including those discussed here, are thermally incompatible. Swelling in a solvent vapor, called solvent annealing, provides sufficient mobility for self assembly. Solvent annealing proved critical to forming ordered structures of functional polar-nonpolar block copolymer thin films. Thermal instability initially led to limited self assembly of combined topdown/bottom-up block copolymer systems. In this case, photolithographic functionality has been designed into block copolymers, allowing the majority component of a block copolymer to behave as a negative-tone photoresist. Solvent vapor annealing has provided a simple and inexpensive method for allowing the bottom-up self assembly of these top-down photopatternable materials. An additional benefit of solvent annealing is the ability to reversibly tune the morphology formed using the selectivity of different swelling solvents to the two blocks: that is, the choice of solvent for annealing directs the formation of different morphologies in the dried film, here spherical and cylindrical. This behavior is reversible, alternating annealing sessions lead to switching of the morphology in the film. Secondary ordering techniques applied in tandem with solvent annealing can be used to further control the self assembly and give highly ordered block copolymer domains. Here we demonstrate the use of graphoepitaxy to align block copolymer self assembly to patterns in substrates. The combination of block copolymer self assembly with lithographic crosslinking in films was initially pursued to allow precise location of assembled patterns. Taking this behavior a step further, we combine solvent annealing, used to reversibly tune the self-assembled morphology, and lithographic patterning, used to prevent switching in exposed regions. This combined process has provided a method for selectively patterning 100 nm-wide domains of spherical morphology within regions of parallel-oriented cylindrical morphology. We also investigate solvent annealing of a block copolymer blended with a hydrogen bonding material that selectively segregates into the polar block. Blending provides a method of tuning the periodicity upon solvent annealing for self assembly, with morphology control again possible by solvent selectivity. Selective extraction of the blended material forms voids displaying the tunable periodicity, and the pattern is then transferred by templating to inorganic materials.

Download or read book Nanostructured Polymer Blends written by Gity Mir Mohamad Sadeghi and published by Elsevier Inc. Chapters. This book was released on 2013-11-28 with total page 121 pages. Available in PDF, EPUB and Kindle. Book excerpt: Block copolymers (BCPs) consist of two or more chemically different polymers connected covalently, and are polymer alloys. Due to their thermodynamic incompatibility and chain connectivity, the phase separation between two (or more) blocks occurs only in a tens of nanometers range. Nanostructures are based on block copolymer self-assembly. They are functional nanomaterials less than 100nm in size and have received extensive scientific and technological attention due to their potential applications in electronic, biomedical, and optical materials. This chapter examines a variety of different synthetic strategies for preparation of linear diblock copolymers by anionic polymerization. Triblocks can be synthesized according to an appropriate synthetic pathway, depending on the monomers used and their sequence in the triblock chain. Nonlinear block copolymers including star block copolymers, graft copolymers, miktoarm star copolymers, cyclic block copolymers, and other complex architectures are explained. Microphase separation drives BCPs to self-assemble, resulting in ordered nanostructures, including spheres, cylinders, gyroids, and lamellae, depending on the composition of the BCP. In nanotechnology, self-assembly (SA) underlies various types of molecular structures built from nanoparticles, nanotubes, or nanorods. Supramolecular structures generated from amphiphilic block copolymers are characterized by a slow rate of intermicellar chain exchange which makes them interesting for a variety of applications. Basic principles of self-assembly and micellization of block copolymers in dilute solution, methods for stabilization of the macromolecular aggregates, are discussed. Stabilized nanoparticles, the so-called “smart materials,” which show responses to environmental changes (pH, temperature, ionic strength, etc.), are presented with a focus on their applications.

Download or read book Dynamic Temperature Gradient Directed Self assembly of Block Copolymer nanoparticle Thin Films written by Ren Zhang (Chemical engineer) and published by . This book was released on 2013 with total page 57 pages. Available in PDF, EPUB and Kindle. Book excerpt: Block copolymers (BCPs) have received considerable attention as a promising platform for synthesis of heterogeneous nanomaterials and fabrication of nanostructures with improved electrical, optical, or mechanical properties. Here we demonstrate a facile fabrication strategy towards long-range ordered block copolymer/nanoparticle (BCP/NP) hybrid structures utilizing a novel dynamic thermal field-induced gradient soft-shear process (CZA-SS). Structural uniformity of nanocomposite films is quantified in terms of the orientation order parameter (S) and it is demonstrated that CZA-SS can facilitate unidirectional alignment with low loading fraction of AuNP additives. The application of sharp dynamic thermal gradient process (CZA-S) is shown to result in the morphological transition from out-of plane to in-plane cylinder orientation that is rationalized as a consequence of suppressed normal expansion of AuNP filled BCP films. Our current work may open new avenues for fabrication of unidirectional oriented hybrid materials,