Influence of Osmotic Pressure on Nanostructures in Thin Films of a Weakly-Segregated Block Copolymer and Its Blends with a Homopolymer

We studied the influence of osmotic pressure on nanostructures in thin films of a symmetric weakly-segregated polystyrene-block-poly (methyl methacrylate), P(S-b-MMA), block copolymer and its mixtures with a polystyrene (PS) homopolymer of various compositions. Thin films were deposited on substrates through surface neutralization. The surface neutralization results from the PS mats, which were oxidized and cross-linked by UV-light exposure. Thus, thermal annealing produced perpendicularly oriented lamellae and perforated layers, depending on the content of added PS chains. Nevertheless, a mixed orientation was obtained from cylinders in thin films, where a high content of PS was blended with the P(S-b-MMA). A combination of UV-light exposure and acetic acid rinsing was used to remove the PMMA block. Interestingly, the treatment of PMMA removal inevitably produced osmotic pressure and consequently resulted in surface wrinkling of perpendicular lamellae. As a result, a hierarchical structure with two periodicities was obtained for wrinkled films with perpendicular lamellae. The formation of surface wrinkling is due to the interplay between UV-light exposure and acetic acid rinsing. UV-light exposure resulted in different mechanical properties between the skin and the inner region of a film. Acetic acid rinsing produced osmotic pressure. It was found that surface wrinkling could be suppressed by reducing film thickness, increasing PS content and using high-molecular-weight P(S-b-MMA) BCPs.

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Degradation in a Methyl-phenyl Co-Polymeric Polysilane for LED Applications

MRS Proceedings ◽

10.1557/proc-769-h4.3 ◽

2003 ◽

Vol 769 ◽

Cited By ~ 2

Author(s):

Asha Sharma ◽

Deepak ◽

Monica Katiyar ◽

Satyendra Kumar ◽

V. Chandrasekhar ◽

...

Keyword(s):

Thin Films ◽

Molecular Weight ◽

Light Source ◽

Room Temperature ◽

Light Exposure ◽

Room Temperature Photoluminescence ◽

Pl Spectrum ◽

Pl Intensity ◽

Methyl Phenyl

AbstractThe optical degradation of polysilane copolymer has been studied in spin cast thin films and solutions using light source of 325 nm wavelength. The room temperature photoluminescence (PL) spectrum of these films show a sharp emission at 368 nm when excited with a source of 325 nm. However, the PL intensity deteriorates with time upon light exposure. Further the causes of this degradation have been examined by characterizing the material for its transmission behaviour and changes occurring in molecular weight as analysed by GPC data.

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Mechanism of Surfactant Removal from Ordered Nanocomposite Silica Thin Films by Deep-UV Light Exposure

MRS Proceedings ◽

10.1557/proc-788-l7.11 ◽

2003 ◽

Vol 788 ◽

Cited By ~ 2

Author(s):

Andrew M. Dattelbaum ◽

Meri L. Amweg ◽

Julia D. Ruiz ◽

Laurel E. Ecke ◽

Andrew P. Shreve ◽

...

Keyword(s):

Thin Film ◽

Thin Films ◽

Self Assembly ◽

Uv Light ◽

Light Exposure ◽

Complete Removal ◽

Combined Application ◽

Silica Thin Films ◽

Deep Uv ◽

Surfactant Removal

ABSTRACTIn recent years, methods have been developed for the generation of complex ordered nanocomposite materials through organic templating of inorganic structures. One approach involves preparation of composite materials by an evaporation induced self-assembly process involving organization of organic surfactants and formation of inorganic silica from soluble precursors. Recently, we have shown that deep-UV light (185–254nm) is efficient at removing the surfactant microphase for a routine production of well-ordered mesoporous silica thin films. Here we probe the evolution of surfactant removal from nanocomposite thin film silica mesophases as a function of deep-UV exposure using a combined application of FTIR and single wavelength ellipsometry. Taken together, these data indicate that surfactant removal occurs in a step-wise fashion with the formation of oxidized intermediates prior to complete removal of the surfactant from the thin film.

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Mechanical Properties of UV Irradiated Bio Polymer Thin Films Doped with Titanium Dioxide

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.748.165 ◽

2013 ◽

Vol 748 ◽

pp. 165-169 ◽

Cited By ~ 5

Author(s):

M. Rahmah Siti ◽

Anika Zafiah M. Rus ◽

S. Nurulsaidatulsyida ◽

D.A. Talib ◽

T.M.Y.S. Tuan Ya

Keyword(s):

Thin Films ◽

Mechanical Properties ◽

Tensile Strength ◽

Titanium Dioxide ◽

Exposure Time ◽

Uv Light ◽

Polymer Thin Films ◽

Testing Machine ◽

Hydroxyl Group ◽

Cumulative Strain

This study reports on the effect of UV-light on the mechanical properties of bio polymer thin films (BPF) doped with 10 % Titanium Dioxide (TiO2). Bio monomer was mixed with 4, 4-methylenebis (phenylisocyanate) (MDI) to produce neat BPF and TiO2 was added to form BPF doped with 10 % TiO2. The film samples were irradiated in UV Accelerated Weatherometer at 50 °C with different exposure time. Universal Testing Machine was used to measure the tensile strength and the fracture surfaces of the tensile specimens were observed by Scanning Electron Microscopy (SEM). The maximum tensile strength of UV irradiated neat BPF is lower than BPF doped with 10 % TiO2 of 3.5 MPa and 4.2 MPa respectively. Stress of neat BPF was decreased from 3.7 MPa to 3.2 MPa after 144 hours of UV exposure at 50 °C while BPF doped with 10 % TiO2 decrease from 4.7 to 3.6 MPa. The Modulus Young of neat BPF is lower than BPF doped with 10 % TiO2 which are 0.32 GPa and 0.33 GPa respectively. The cumulative strain percentage irradiated neat BPF is lower than BPF doped with 10 % TiO2 with 98.7 % and 113.7 % respectively. Unexposed UV light of neat BPF and BPF doped with 10 % TiO2 were observed by SEM shows smooth fracture and brittle fracture respectively. Neat BPF and BPF doped with 10 % TiO2 exposed to UV light show higher ductility property as compared to unexposed BPF. The higher the exposure time of BPF to UV light, revealed systematic increment of tensile strength due to increased crosslink between isocyanate and hydroxyl group.

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Nanoscale Mapping of Thermal and Mechanical Properties of Bare and Metal-Covered Self-Assembled Block Copolymer Thin Films

ACS Applied Polymer Materials ◽

10.1021/acsapm.9b00924 ◽

2019 ◽

Vol 2 (2) ◽

pp. 487-496 ◽

Cited By ~ 1

Author(s):

Alexandros El Sachat ◽

Jean Spièce ◽

Charalambos Evangeli ◽

Alexander James Robson ◽

Martin Kreuzer ◽

...

Keyword(s):

Thin Films ◽

Mechanical Properties ◽

Block Copolymer ◽

Thermal And Mechanical Properties ◽

Self Assembled

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Tribomechanical Properties of Polymeric Composites Based on Mixture of Ultra High Molecular Weight Polyethylene and Polyamide

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.770.87 ◽

2015 ◽

Vol 770 ◽

pp. 87-92

Author(s):

Sergey Panin ◽

Lyudmila А. Kornienko ◽

Nguyen Xuan Thuc ◽

Larisa R. Ivanova ◽

Mikhail A. Poltaranin ◽

...

Keyword(s):

Mechanical Properties ◽

Molecular Weight ◽

Block Copolymer ◽

High Molecular Weight ◽

Sliding Friction ◽

Polymeric Composites ◽

Flow Index ◽

Dry Sliding ◽

Dry Sliding Friction ◽

Ultra High Molecular Weight

In order to find out optimum filler to increase manufacturability (extrudability) of composites based on ultra-high molecular weight polyethylene (UHMWPE) matrix as well as to develop polymer-polymeric composites with improved tribological characteristics, the structure, mechanical properties and wear resistance of UHMWPE mixtures with elasticizing block-copolymer PA-b-LLDPE (UHMWPE + PA-b-LLDPE) was investigated under dry sliding friction. Applied aspect of the study is related to the selection of commercially available fillers being compatible with UHMWPE for manufacturing anti-frictional extrudable nanocomposites. It is shown that as compared with pure UHMWPE mechanical properties (ultimate strength, value of elongation at failure) do not vary substantially, but the wear rate under dry sliding friction of polymeric composites UHMWPE + n wt.% PA-b-LLDPE is reduced only when block copolymer weight fraction is less than ≤ 5 wt.%. By the polymeric filling an important technological characteristic - specific pressure of extrusion (that is proportional to melt flow index) might be decreased. Permolecular structure and wear track surfaces of polymer-polymer composites UHMWPE + n wt.% PA-b-LLDPE was examined and numerically characterized.

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An Inorganic Rubber

Rubber Chemistry and Technology ◽

10.5254/1.3539383 ◽

1932 ◽

Vol 5 (4) ◽

pp. 585-586

Author(s):

Paul Renaud

Keyword(s):

Mechanical Properties ◽

Molecular Weight ◽

Low Temperature ◽

Osmotic Pressure ◽

The Other ◽

Low Molecular Weight ◽

Solid Mixture

Abstract The hypotheses generally accepted for the structure of gels explain these phenomena in detail. The trimer, polymerized by heating, gives rise to chains of different sizes, which are able to unite and form a network. The latter contains in its meshes the trimer which has not reacted, and also polymers of low molecular weight. According to whether the latter form a liquid or solid mixture, the gum is optically liquid or solid. At low temperature, the network itself assumes a rigidity which it communicates to the entire mass. The thermo-mechanical properties show that this is true of all the gums. The presence of the network has little influence on the fusion of the intercellular product, whereas its influence on vaporization is great; in fact, the volume is as little affected by fusion as it is greatly changed by vaporization. It must therefore be the case that rupture of the meshes by pressure is more rapid than their formation by polymerization. The influence of benzine and of water, one of which dissolves the intercellular products and the other does not, shows the influence of osmotic pressure, to which Duclaux (see Bull. soc. chim., 33, 36 (1923)) has called attention.

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Equilibrium and Nonequilibrium Nanoscale Ordering of Polystyrene-b-poly(N,N′-diethylaminoethyl methacrylate), a Block Copolymer Carrying Tertiary Amine Functional Groups

Journal of Nanomaterials ◽

10.1155/2014/725356 ◽

2014 ◽

Vol 2014 ◽

pp. 1-14 ◽

Cited By ~ 3

Author(s):

Pedro Navarro-Vega ◽

Arturo Zizumbo-López ◽

Angel Licea-Claverie ◽

Alejandro Vega-Rios ◽

Francisco Paraguay-Delgado

Keyword(s):

Thin Films ◽

Gold Nanoparticles ◽

Free Radical ◽

Block Copolymer ◽

Radical Polymerization ◽

Tertiary Amine ◽

Chain Transfer ◽

Uv Light ◽

Mica Substrate ◽

The Core

Poly(styrene)-b-poly(N,N′-diethylaminoethyl methacrylate) (PS-b-PDEAEM) block copolymer was synthesized by RAFT free-radical polymerization using a trithiocarbonate type of chain transfer agent (CTA). Several block copolymer compositions were achieved maintaining low polydispersities by using PS as macro-CTA in the first step. Thin films of PS60%-b-PDEAEM40%were deposited over mica substrate, and its equilibrium and nonequilibrium nanostructures were studied. Lamellar (equilibrium), bicontinuous (nonequilibrium) and detached nanoflakes (nonequilibrium), were obtained by using different annealing methods. Mixing nanocomposites of gold nanoparticles/PDEAEM in the block copolymer resulted in the formation of toroidal nanostructures confining gold nanoparticles to the core of those nanostructures. The same toroidal nanostructure was achieved by different annealing methods, including irradiation with UV light for 15 min. Electron micrographs show clearly this different type of arrays.

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Nondestructive quantitative synchrotron grazing incidence X-ray scattering analysis of cylindrical nanostructures in supported thin films

Journal of Applied Crystallography ◽

10.1107/s0021889807000817 ◽

2007 ◽

Vol 40 (2) ◽

pp. 305-312 ◽

Cited By ~ 36

Author(s):

Jinhwan Yoon ◽

Seung Yun Yang ◽

Byeongdu Lee ◽

Wonchul Joo ◽

Kyuyoung Heo ◽

...

Keyword(s):

Thin Films ◽

Acetic Acid ◽

Data Analysis ◽

Scattering Theory ◽

Light Exposure ◽

Grazing Incidence ◽

Nondestructive Analysis ◽

X Ray ◽

X Ray Scattering ◽

Ray Scattering

Nondestructive nanostructural analysis is indispensable in the development of nanomaterials and nanofabrication processes for use in nanotechnology applications. This paper demonstrates a quantitative, nondestructive analysis of nanostructured thin films supported on substrates and their templated nanopores by using grazing incidence X-ray scattering and data analysis with a derived scattering theory. The analysis disclosed that vertically oriented nanodomain cylinders had formed in 20–100 nm thick films supported on substrates, which consisted of a mixture of poly(styrene-b-methyl methacrylate) (PS-b-PMMA) and PMMA homopolymer, and that the PMMA nanodomain cylinders were selectively etched out by ultraviolet light exposure and a subsequent rinse with acetic acid, resulting in a well ordered nanostructure consisting of hexagonally packed cylindrical nanopores.

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Utilization of Chicken By-Products to Form Collagen Films

Journal of Food Processing ◽

10.1155/2015/247013 ◽

2015 ◽

Vol 2015 ◽

pp. 1-6 ◽

Cited By ~ 4

Author(s):

Kumudini A. Munasinghe ◽

Jurgen G. Schwarz ◽

Matthew Whittiker

Keyword(s):

Mechanical Properties ◽

Molecular Weight ◽

Acetic Acid ◽

Freeze Drying ◽

Distilled Water ◽

Texture Analyzer ◽

Ph Values ◽

Chicken Skin ◽

Alternate Source ◽

By Products

Chicken collagen casings could be an alternate source of collagen casings that are manufactured for sausages. The overall objective of this project was to extract chicken collagen from by-products of the broiler processing industries and to explore the possibility of making films. Chicken skin was washed, ground, and pretreated to remove the noncollagenous compounds. Collagen was extracted using acetic acid and pepsin. Solubilized collagen was salted-out and centrifuged at 20,000 ×g at 4°C for one hour. The precipitates were dissolved in 0.5 M acetic acid and dialyzed against 0.1 M acetic acid and distilled water before freeze-drying. Molecular weight, collagen solubility at different pH values, and NaCl concentrations were determined. TA-XT2 texture analyzer was used to characterize mechanical properties of collagen films. The highest collagen solubility was obtained at pH 2 and 2% NaCl. Hand-homogenized, nonfiltered, and conditioned samples had the highest hardness (3,262 g) and the least brittleness (30.5 mm). These results demonstrate that chicken collagen extracted from chicken by-products has the ability to form films and could be considered for making casings or be used in various other industries.

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