Effect of block copolymer dopants and alkylsilane monolayers on the fracture toughness of polystyrene-glass interfaces

Calistri-Yeh, M.; Park, E. J.; Krämer, Edward J.; Smith, J. J.; Sharma, Ram V.

doi:10.1007/bf01151511

Cited by 3 publications

(3 citation statements)

References 19 publications

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“…The behavior of the monolayers when constrained under a layer of high molecular weight polystyrene appears to be much different than that when the monolayers are the exposed surfaces. − Fracture toughness experiments performed by Smith et al and Calistri-Yeh et al …”

Section: Resultsmentioning

confidence: 99%

Thermal Stability of Self-Assembled Monolayers from Alkylchlorosilanes

et al. 1996

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Contact angle measurements and scanning force microscopy (SFM) have been used to study the morphology of self-assembled monolayers of octadecyltrichlorosilane (OTS) and undecyltrichlorosilane (UTS) on silicon oxide surfaces as a function of annealing temperature. Characterization of the monolayers before annealing indicates that the as-formed monolayers cover the substrate fully and have thicknesses of 2.9 and 1.5 nm, respectively, with the average surface having a roughness of approximately 0.3 nm. Water contact angle results and SFM roughness analysis showed that UTS monolayers annealed for 2 h at temperatures over 125 °C exhibited permanent changes in monolayer structure. Experimental data indicated a higher transition temperature for permanent structural changes for the OTS monolayers. Water contact angle measurements indicated a transition centered at 125 °C, hexadecane contact angle measurements indicated a transition around 130 °C, and SFM indicated a transition centered at 155 °C for OTS monolayers. We have observed that contact angle measurements can be sensitive to surface structure on an angstrom length scale. These results observed after 2 h are not equilibrium results, as evidenced by the further development in the monolayer after an anneal for 5 h. Thermodynamic considerations support the earlier (lower temperature) changes observed for UTS than for OTS monolayers. The observed transition is likely the result of hydrolysis of the organic molecules by water molecules existing at the monolayer-substrate interface.

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Section: Resultsmentioning

confidence: 99%

Thermal Stability of Self-Assembled Monolayers from Alkylchlorosilanes

et al. 1996

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“…PS- b -P2VP(S) forms a spherical morphology; P2VP spheres are embedded in the PS matrix with well-ordered BCC structure; while PS- b -P2VP(L) has a lamellar structure, with lamellae stacked parallel to the substrate. This parallel orientation is a well-documented result which originates from the strong interaction between the poly(2-vinylpyridine) block and the substrate . The schematic structures of each composite were illustrated in Figure (a), with the chemical structure of PS- b -P2VP shown in Figure (b).…”

mentioning

confidence: 85%

“…This parallel orientation is a well-documented result which originates from the strong interaction between the poly(2-vinylpyridine) block and the substrate. 21 The schematic structures of each composite were illustrated in Figure 1(a), with the chemical structure of PS-b-P2VP shown in Figure 1(b). A high transparency (>92% transmittance in visible range, Figure 2) was achieved for all samples (both pure block polymers and the block copolymer hybrids), as shown in Figure 2; this indicates that the MgO nanocrystals are well-distributed in the composite samples and not aggregating or undergoing macroscale phase segregation.…”

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confidence: 99%

Enhanced Water Vapor Blocking in Transparent Hybrid Polymer–Nanocrystal Films

et al. 2014

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Highly transparent and effective encapsulating materials have become increasingly important for photovoltaic (PV) modules to prevent water vapor molecules from permeating PV cells. The composite consists of block copolymer (PS-b-P2VP), comprised of hydrophobic and hydrophilic parts, and hygroscopic nanocrystals (Magnesium Oxide, MgO) incorporated to enhance water vapor blocking by both presenting obstacles for mass transport and also scavenging water molecules. The water vapor transmission rate (WVTR) values were reduced ∼3000 times, compared to homopolymer (PS), for both polymer and composite samples. Achieving both high transparency and low WVTR, it is expected that the composite materials can function as an excellent water vapor blocking layer for PV modules.

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Interfacial adhesion in model bioblends

Biresaw

Carriere

Willett

2004

J of Applied Polymer Sci

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Model bioblends were investigated for interfacial adhesion using the asymmetric double cantilever beam (ADCB) fracture method. The model bioblends comprised two synthetic polymer components, one of which was the nonbiodegradable polymer polystyrene (PS). The second component was a synthetic biodegradable polyester, which was either polycaprolactone (PCL) or Eastar Bio Copolyester® (EBU). The critical strain energy release rate (G Ic ) data from the ADCB fracture experiments on the model bioblends decreased in the order: PCL/PS Ͼ EBU/PS. This was opposite to the reported order in the interfacial tension of these bioblends. It is concluded that the relative interfacial adhesion of the model bioblends was due to better compatibility in PCL/PS blends over that in EBU/PS blends. © 2004 Wiley Periodicals, Inc.* J Appl Polym Sci 94: [65][66][67][68][69][70][71][72][73] 2004 Key words: asymmetric double cantilever beam fracture; bioblend; biodegradable polyester; interfacial adhesion; critical strain energy release rate

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Effect of block copolymer dopants and alkylsilane monolayers on the fracture toughness of polystyrene-glass interfaces

Cited by 3 publications

References 19 publications

Thermal Stability of Self-Assembled Monolayers from Alkylchlorosilanes

Thermal Stability of Self-Assembled Monolayers from Alkylchlorosilanes

Enhanced Water Vapor Blocking in Transparent Hybrid Polymer–Nanocrystal Films

Interfacial adhesion in model bioblends

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