Block Copolymer Thin Films Above and Below the Order-Disorder Transition Temperature

2000 ◽  
Vol 629 ◽  
Author(s):  
Ratchana Limary ◽  
Peter F. Green
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Molecular Weight ◽  
Transition Temperature ◽  
Block Copolymer ◽  
Film Thickness ◽  
Diblock Copolymer ◽  
Diblock Copolymers ◽  
Microphase Separation ◽  
Disorder Transition Temperature

ABSTRACTSymmetric diblock copolymers undergo a disorder to order transition below a microphase separation transition temperature. In this temperature range the structure is characterized by alternating lamellae of thickness L. In thin film geometries, the lamellae are oriented normal to the substrate if there is a preferential interaction between either of the block constituents and the substrate/copolymer or copolymer/vacuum interfaces. Depending on the relation between the film thickness and L, the topography of the film might comprise of holes, islands or spinodal-like structures. We show that in a polystyrene-b-poly(methyl methacrylate) diblock copolymer of molecular weight 20, 000 g/mol, above the microphase separation transition temperature, the topography of the film depends on the thickness. A heirarchy of bicontinuous patterns and holes is observed with increasing film thickness for films thinner than 35 nm.

Nanostructured organic radical cathodes from self-assembled nitroxide-containing block copolymer thin films

2015 ◽  
Vol 3 (38) ◽  
pp. 19575-19581 ◽  
Author(s):  
G. Hauffman ◽  
A. Vlad ◽  
T. Janoschka ◽  
U. S. Schubert ◽  
J.-F. Gohy
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Block Copolymer ◽  
Diblock Copolymers ◽  
Organic Radical ◽  
Nanostructured Thin Film ◽  
Self Assembled

Nanostructured thin film organic radical cathodes have been prepared from poly(styrene)-block-poly(2,2,6,6-tetramethylpiperidinyloxy-4-yl methacrylate) diblock copolymers.

scholarly journals Preparation of Janus nanoparticles from block copolymer thin films using triazolinedione chemistry

RSC Advances ◽  
2017 ◽  
Vol 7 (59) ◽  
pp. 37048-37054 ◽  
Author(s):  
Elio Poggi ◽  
Wolfgang Ouvry ◽  
Bruno Ernould ◽  
Jean-Pierre Bourgeois ◽  
Subrata Chattopadhyay ◽  
...  
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Block Copolymer ◽  
Click Chemistry ◽  
Diblock Copolymer ◽  
Nanostructured Thin Film ◽  
Janus Nanoparticles

A nanostructured thin film obtained from a polystyrene-block-poly(4-vinylpyridine) diblock copolymer was used as a template to produce Janus-type nanoparticles via triazolinedione-ene click chemistry.

scholarly journals Self-Assembly in ultrahigh molecular weight sphere-forming diblock copolymer thin films under strong confinement

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Wei Cao ◽  
Senlin Xia ◽  
Michael Appold ◽  
Nitin Saxena ◽  
Lorenz Bießmann ◽  
...  
Keyword(s):  
Thin Films ◽  
Molecular Weight ◽  
Film Thickness ◽  
Self Assembly ◽  
Diblock Copolymers ◽  
Grazing Incidence ◽  
Structure Evolution ◽  
Solvent Vapor ◽  
Chain Mobility ◽  
Ultrahigh Molecular Weight

AbstractUltrahigh molecular weight (UHMW) diblock copolymers (DBCs) have emerged as a promising template for fabricating large-sized nanostructures. Therefore, it is of high significance to systematically study the influence of film thickness and solvent vapor annealing (SVA) on the structure evolution of UHMW DBC thin films. In this work, spin coating of an asymmetric linear UHMW polystyrene-block-poly(methyl methacrylate) (PS-b-PMMA) DBC is used to fabricate thin films, which are spherically structured with an inter-domain distance larger than 150 nm. To enhance the polymer chain mobility and facilitate approaching equilibrium nanostructures, SVA is utilized as a post-treatment of the spin coated films. With increasing film thickness, a local hexagonal packing of PMMA half-spheres on the surface can be obtained, and the order is improved at larger thickness, as determined by grazing incidence small angle X-ray scattering (GISAXS). Additionally, the films with locally hexagonal packed half-spherical morphology show a poor order-order-poor order transition upon SVA, indicating the realization of ordered structure using suitable SVA parameters.

Investigation of Diblock Copolymer thin film Morphology for Nanolithography

1996 ◽  
Vol 461 ◽  
Author(s):  
Miri Park ◽  
Christopher Harrison ◽  
Paul M. Chaikin ◽  
Richard A. Register ◽  
Douglas Adamson ◽  
...  
Keyword(s):  
Thin Films ◽  
Silicon Nitride ◽  
Diblock Copolymer ◽  
Diblock Copolymers ◽  
Microphase Separation ◽  
Large Area ◽  
Etching Technique ◽  
Copolymer Films ◽  
Self Assembled ◽  
Self Assembled Layer

ABSTRACTThe microphase separated morphology of diblock copolymers can be used to generate well-ordered nanometer scale patterns over a large area. To achieve this goal, it is important to understand and control the behavior of diblock copolymer thin films on substrates, which can differ from the bulk behavior. We have investigated the morphologies and ordering in thin polystyrene-polybutadiene (PS-PB) diblock copolymer films on bare silicon and silicon nitride substrates, and also on polymethylmethacrylate (PMMA) coated substrates. The PS-PB copolymers are synthesized to form, in bulk, PB cylinders or spheres in a PS matrix. In thin films (10–60 nm thick), prepared by spin-coating, we observe that the morphology and ordering of the microdomains are affected by strong wetting constraints and a reduced chain mobility on the substrate. The thinnest self-assembled layer of the copolymer films shows no in-plane microphase separation on both types of substrates. The PS blocks wet the PMMA substrates whereas the PB blocks wet the bare substrates as well as the air interface. Hence, different film thicknesses are necessary on the two types of substrates to obtain a uniform film of the first self-assembled cylindrical or spherical microdomain layer. The first layer of the cylindrical copolymer can vary from cylindrical to spherical morphology with a few nanometer decrease in film thickness. In the case of spherical PS-PB diblock copolymer films, we observe that the ordering of the microdomains is improved in the films on the PMMA substrates, compared to those on the bare substrates. We also demonstrate a successful transfer of the microdomain patterns to silicon nitride substrates by a reactive ion etching technique.

Tem Studies of Single and Double Microdomain Layers of Block Copolymer

1998 ◽  
Vol 4 (S2) ◽  
pp. 818-819
Author(s):  
N. Yao ◽  
M. Park ◽  
C. Harrison ◽  
D. H. Adamson ◽  
P. M. Chaikin ◽  
...  
Keyword(s):  
Thin Films ◽  
Glass Transition ◽  
Block Copolymer ◽  
Diblock Copolymers ◽  
Microphase Separation ◽  
Covalent Bond ◽  
Inorganic Materials ◽  
Polymer Chains ◽  
Copolymer Films ◽  
Cylinders And Spheres

Diblock copolymers consist of two chemically different polymer chains (or blocks) joined by a covalent bond. Because of the incompatibility between the two blocks and connectivity constraints, diblock copolymers spontaneously self-assemble into microphase-separated nanometer size domains that exhibit ordered morphologies at equilibrium. Commonly observed microdomain morphologies in bulk samples are periodic arrangements of lamellae, cylinders, and spheres. Recent studies show that the thin films of such block copolymers are of great potential for many nanoapplications including nanolithography and template synthesis for inorganic materials. Here, we report TEM studies of osmylated and ozonated thin diblock copolymer films.An asymmetric block copolymer was synthesized with a composition of 36 kg/mol for the poly(styrene)(PS) block and 11 kg/mole for the poly (butadiene)(PB) block such that the microphase separation produces PB cylinders in a matrix of PS. The films were spin-coated from solution onto thin silicon nitride windows and annealed above the glass transition temperature in vacuum.

Enhanced microphase separation of thin films of low molecular weight block copolymer by the addition of an ionic liquid

Soft Matter ◽  
2019 ◽  
Vol 15 (48) ◽  
pp. 9991-9996
Author(s):  
Dongxue Li ◽  
Chun Zhou ◽  
Shisheng Xiong ◽  
Xin-Ping Qu ◽  
Gordon S. W. Craig ◽  
...  
Keyword(s):  
Thin Films ◽  
Molecular Weight ◽  
Ionic Liquid ◽  
Block Copolymer ◽  
Microphase Separation ◽  
Low Molecular Weight

Enhanced microphase separation of a high-χ block copolymer by adding a selective ionic liquid to the block copolymer in solution.

scholarly journals Experimental Study on the Thickness-Dependent Hardness of SiO2 Thin Films Using Nanoindentation

Coatings ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 23
Author(s):  
Weiguang Zhang ◽  
Jijun Li ◽  
Yongming Xing ◽  
Xiaomeng Nie ◽  
Fengchao Lang ◽  
...  
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Grain Size ◽  
Integrated Circuits ◽  
Film Thickness ◽  
Depth Range ◽  
Micro Electro Mechanical Systems ◽  
Si Substrates ◽  
Sio2 Thin Film ◽  
Average Grain Size

SiO2 thin films are widely used in micro-electro-mechanical systems, integrated circuits and optical thin film devices. Tremendous efforts have been devoted to studying the preparation technology and optical properties of SiO2 thin films, but little attention has been paid to their mechanical properties. Herein, the surface morphology of the 500-nm-thick, 1000-nm-thick and 2000-nm-thick SiO2 thin films on the Si substrates was observed by atomic force microscopy. The hardnesses of the three SiO2 thin films with different thicknesses were investigated by nanoindentation technique, and the dependence of the hardness of the SiO2 thin film with its thickness was analyzed. The results showed that the average grain size of SiO2 thin film increased with increasing film thickness. For the three SiO2 thin films with different thicknesses, the same relative penetration depth range of ~0.4–0.5 existed, above which the intrinsic hardness without substrate influence can be determined. The average intrinsic hardness of the SiO2 thin film decreased with the increasing film thickness and average grain size, which showed the similar trend with the Hall-Petch type relationship.

scholarly journals Precise control of Jeff=12 magnetic properties in Sr2IrO4 epitaxial thin films by variation of strain and thin film thickness

2020 ◽  
Vol 102 (21) ◽  
Author(s):  
Stephan Geprägs ◽  
Björn Erik Skovdal ◽  
Monika Scheufele ◽  
Matthias Opel ◽  
Didier Wermeille ◽  
...  
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Magnetic Properties ◽  
Film Thickness ◽  
Epitaxial Thin Films ◽  
Thin Film Thickness ◽  
Precise Control
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