Distribution of glass transition temperature in multilayered poly(methyl methacrylate) thin film supported on a Si substrate as studied by neutron reflectivity

Inoue, Rintaro; Nakamura, Makoto; Matsui, Kazuya; Kanaya, Toshiji; Nishida, Koji; Hino, Masahiro

doi:10.1103/physreve.88.032601

Cited by 41 publications

(34 citation statements)

References 45 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This must be due to the interfacial hard layer near the substrate because of strong interactions between the PMMA and the Si surface. These results as well as recent intensive studies [22][23][24][25][26][27][28][29] suggest that polymer thin films have very heterogeneous dynamics or structure along the depth direction, consisting of a surface mobile layer, a middle bulklike layer, and an interfacial hard layer.…”

Section: Introductionsupporting

confidence: 62%

“…We have performed neutron reflectivity measurements on five-layer PS and PMMA thin films consisting of alternatively stacked deuterated PS (dPS) and hydrogenated PS (hPS) (or PMMA) layers (dPS/hPS/dPS/hPS/dPS) [27] (or dP-MMA/hPMMA/dPMMA/hPMMA/dPMMA) [28] to evaluate the heterogeneous dynamics of thin films directly. In these experiments, we have evaluated the thickness of each layer * Present address: Institute for Chemical Research, Kyoto University, Uji, Kyoto 611-0011, Japan; kanaya@scl.kyoto-u.ac.jp as a function of temperature and estimated T g of each layer.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Distribution of glass transition temperaturesTgin polystyrene thin films as revealed by low-energy muon spin relaxation: A comparison with neutron reflectivity results

et al. 2015

Self Cite

View full text Add to dashboard Cite

In a previous paper [Phys. Rev. E 83, 021801 (2011)] we performed neutron reflectivity (NR) measurements on a five-layer polystyrene (PS) thin film consisting of alternatively stacked deuterated polystyrene (dPS) and hydrogenated polystyrene (hPS) layers (dPS/hPS/dPS/hPS/dPS, ∼100 nm thick) on a Si substrate to reveal the distribution of Tg along the depth direction. Information on the Tg distribution is very useful to understand the interesting but unusual properties of polymer thin films. However, one problem that we have to clarify is if there are effects of deuterium labeling on Tg or not. To tackle the problem we performed low-energy muon spin relaxation (μSR) measurements on the above-mentioned deuterium-labeled five-layer PS thin film as well as dPS and hPS single-layer thin films ∼100 nm thick as a function of muon implantation energy. It was found that the deuterium labeling had no significant effects on the Tg distribution, guaranteeing that we can safely discuss the unusual thin film properties based on the Tg distribution revealed by NR on the deuterium-labeled thin films. In addition, the μSR result suggested that the higher Tg near the Si substrate is due to the strong orientation of phenyl rings.

show abstract

Section: Introductionsupporting

confidence: 62%

Section: Introductionmentioning

confidence: 99%

Distribution of glass transition temperaturesTgin polystyrene thin films as revealed by low-energy muon spin relaxation: A comparison with neutron reflectivity results

et al. 2015

Self Cite

View full text Add to dashboard Cite

show abstract

“…Furthermore, the glass transition temperature near the surface of the glasses varies from that of the bulk. For example, glass transition temperatures found in a surface layer approximately 1000 Å thick in poly(methyl methacrylate) films differ from those of the bulk . Yu and coworkers reported that diffusion on the surface of glasses was at least 10 6 times faster than bulk diffusion, and glass surface diffusion can cause surface evolution at nm to μm scale, which is a length scale that would be expected to be long enough for (conformationally perturbed) protein molecules to collide with each other in the surface glass layer, causing aggregation.…”

Section: Discussionmentioning

confidence: 99%

Protein Quantity on the Air–Solid Interface Determines Degradation Rates of Human Growth Hormone in Lyophilized Samples

Grobelny

Allmen

et al. 2014

Journal of Pharmaceutical Sciences

View full text Add to dashboard Cite

rhGH was lyophilized with various glass-forming stabilizers, employing cycles that incorporated various freezing and annealing procedures to manipulate glass formation kinetics, associated relaxation processes and glass specific surface areas (SSA’s). The secondary structure in the cake was monitored by IR and in reconstituted samples by CD. The rhGH concentrations on the surface of lyophilized powders were determined from ESCA. Tg, SSA’s and water contents were determined immediately after lyophilization. Lyophilized samples were incubated at 323 K for 16 weeks, and the resulting extents of rhGH aggregation, oxidation and deamidation were determined after rehydration. Water contents and Tg were independent of lyophilization process parameters. Compared to samples lyophilized after rapid freezing, rhGH in samples that had been annealed in frozen solids prior to drying, or annealed in glassy solids after secondary drying retained more native-like protein secondary structure, had a smaller fraction of the protein on the surface of the cake and exhibited lower levels of degradation during incubation. A simple kinetic model suggested that the differences in the extent of rhGH degradation during storage in the dried state between different formulations and processing methods could largely be ascribed to the associated levels of rhGH at the solid-air interface after lyophilization.

show abstract

“…Interest in this field has produced a multitude of research, and we refer the reader to several studies and review articles to gain a broader appreciation for the subject . Positron annihilation lifetime spectroscopy (PALS) and neutron reflectivity have also been used to characterize thin film T g . Although the majority of experimental studies attribute confined T g behavior to strong interfacial influences, these studies relied on models and indirect measurements of local T g to support their conclusions .…”

Section: Confined Polymer Propertiesmentioning

confidence: 99%

21st Century Advances in Fluorescence Techniques to Characterize Glass‐Forming Polymers at the Nanoscale

Burroughs

Christie

Gray

et al. 2017

Macro Chemistry & Physics

View full text Add to dashboard Cite

properties. [9,10] While fluorescence has been used extensively to characterize bulk properties of polymers, including glass transition temperature (T g ) [11][12][13] and polymerization conversion, [13] it is particularly well-suited to study polymers at the nanoscale. This is largely due to the fact that fluorescence techniques enable sensitive and location-specific measurements with high resolution.In this review, we focus on the use of both steady-state and transient fluorescence techniques to characterize physical properties of polymers over nanoscale dimensions. This length scale can refer to film thickness in single-component polymer films, interparticle spacing in nanocomposites, domain spacing in phaseseparated block copolymers, and distance from the polymer-polymer interface in multicomponent immiscible blends. Several geometries characterized via fluorescence are shown in Figure 1. Prior to delving into specific contributions, the basic principles and techniques of fluorescence are presented as well as a brief introduction to the behavior of confined polymers. We then present recent advances in fluorescence techniques for polymer physical characterization under confinement with regards to the glass transition temperature, physical aging, mobility and diffusion, and mechanical response. Through this examination of the literature, we illustrate the unique ability of fluorescence to characterize polymers in confined and complex geometries, providing insights into the influences of interfaces and nanostructure on material properties through sensitive, location-specific measurements. We conclude with a view toward future areas of research in which fluorescence has the potential to be impactful. Introduction to FluorescenceWhen a molecule absorbs energy via light, an electron is excited to a higher energy state, returning to the ground state through either radiative or nonradiative deactivation. This electronic excitation and return to the ground state is a combination of three photophysical processes: absorption, luminescence, and nonradiative decay. [33] Fluorescence is a luminescent process in which the excited-state electron returns to the ground state by emitting a photon, i.e., light. As shown in a simplified Jablonski Polymer CharacterizationCharacterization of polymers at the nanometer-length scale has become increasingly important with the growth and expansion of nanotechnology. Due to limitations of sensitivity and specificity that persist with traditional materials characterization techniques, there is a growing need to develop new tools to measure the properties of confined polymer systems. Within the past 20 years, fluorescence characterization techniques have emerged to address this challenge. This review focuses on the employment of fluorescence techniques such as temperature-and time-dependent steady-state intensity, fluorescence recovery after photobleaching, and nonradiative energy transfer to study polymer behavior at the nanoscale. Properties discussed include glass transition temperatur...

show abstract

Distribution of glass transition temperature in multilayered poly(methyl methacrylate) thin film supported on a Si substrate as studied by neutron reflectivity

Cited by 41 publications

References 45 publications

Distribution of glass transition temperaturesTgin polystyrene thin films as revealed by low-energy muon spin relaxation: A comparison with neutron reflectivity results

Distribution of glass transition temperaturesTgin polystyrene thin films as revealed by low-energy muon spin relaxation: A comparison with neutron reflectivity results

Protein Quantity on the Air–Solid Interface Determines Degradation Rates of Human Growth Hormone in Lyophilized Samples

21st Century Advances in Fluorescence Techniques to Characterize Glass‐Forming Polymers at the Nanoscale

Contact Info

Product

Resources

About