Poly(methyl methacrylate) nanotubes in AAO templates: Designing nanotube thickness and characterizing the T-confinement effect by DSC

Tan, Anthony; Torkelson, John M.

doi:10.1016/j.polymer.2015.11.054

Cited by 26 publications

(20 citation statements)

References 143 publications

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“…Besides crystallization kinetics, other features related to polymer structure, such as crystal orientation and phase transitions inside the AAO template nanopores, have also been the focus of recent research ,,,− as recently reviewed by Muller et al Moreover, it has been also reported that the glass transition temperature of poly(methyl methacrylate) (PMMA) infiltrated in AAO nanocavities differs from that of bulk and the value increases as the diameter of pore nanocavities decreases . Related to PMMA, in the study of the glass transition temperature of the polymer by thermal annealing experiments, Xue and co-workers observed a double glass transition temperature of the PMMA inside the AAO template.…”

Section: Introductionmentioning

confidence: 99%

Effect of Confinement on the Synthesis of PMMA in AAO Templates and Modeling of Free Radical Polymerization

et al. 2017

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The hierarchical surface structure of polymer materials leads to unique properties which are of both academic and commercial interest. In this work we explore the ability to replicate the well-defined surface structure of anodic aluminum oxide (AAO) templates by in situ polymerization of methyl methacrylate. When the reaction is conducted inside the templates, the rate of polymerization was significantly higher and molecular weight was reduced, as compared to the reaction in bulk. These observations were explained using a mathematical model to describe the polymerization based on free-volume theory and confinement effects. As the dimensions of the template are reduced, a catalytic effect on the rate of initiator decomposition leads to a faster polymerization rate in the early stages of polymerization. In addition, due to the confined reaction volume, the rate of termination is increased in the latter stages of the reaction. The two confinement effects combine to lead to lower molecular weight polymers of reduced dispersity in comparison to the reaction conducted in bulk.

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Section: Introductionmentioning

confidence: 99%

Effect of Confinement on the Synthesis of PMMA in AAO Templates and Modeling of Free Radical Polymerization

et al. 2017

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“…Ellipsometry, capillary dilatometry, and X‐ray reflectivity require relatively flat, continuous films to accurately measure T g . While DSC has been used to study 2D‐confined (where two dimensions are restricted to the nanoscale) polymer systems through anodized aluminum oxide (AAO) template‐supported nanorods and nanotubes, sample geometry and interfacial interactions were somewhat limited by template constraints. Additionally, these techniques do not enable location‐specific measurements in the presence of a free surface without costly and time‐intensive scattering and reflectivity studies.…”

Section: Fluorescence To Measure Tg and Physical Aging In Single‐compmentioning

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

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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...

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“…Furthermore, similar polymer phase separations and transformation behaviors at the microscale have also been observed [34,35,36,37,38]. Because of the success of the AAO templating method, many publications have explored various AAO applications such as thermal and physical properties of polymer nanostructures under nanoconfinement conditions, fabrication of higher−order nanostructures, polymerization and crystallization in AAO templates, and the double infiltration nanoencapsulation process [39,40,41,42,43,44,45,46,47,48,49].…”

Section: Introductionmentioning

confidence: 96%

Replication of Mesoscale Pore One-dimensional Nanostructures: Surface-induced Phase Separation of Polystyrene/Poly(vinyl alcohol) (PS/PVA) Blends

2019

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Mesoscale pore one–dimensional (1D) nanostructures, or vertically aligned porous nanostructures (VAPNs), have attracted attention with their excellent hydrophobic properties, ultra−high surface area, and high friction coefficient, compared to conventional vertically aligned nanostructures (VANs). In this study, we investigate the replication of VAPNs produced by the thermal nanoimprint process using anodic aluminum oxide (AAO2) templates (100 nm diameter). Polystyrene/poly(vinyl alcohol) (PS1/PVA) blends, prepared by the advanced melt–mixing process with an ultra–high shear rate, are used to investigate the formation of porosity at the nanometer scale. The results reveal that domain size and mass ratios of PVA precursors in the PS matrix play a dominant role in the interfacial interaction behavior between PS1–PVA–AAO2, on the obtained morphologies of the imprinted nanostructures. With a PVA nanodomain precursor (PS1/PVA 90/10 wt%), the integration of PVA nanodroplets on the AAO2 wall due to the hydrogen bonding that induces the phase separation between PS1–PVA results in the formation of VAPNs after removal of the PVA segment. However, in the case of PVA microdomain precursors (PS1/PVA 70/30 wt%), the structure transformation behavior of PS1 is induced by the Rayleigh instability between PVA encapsulated around the PS1 surfaces, resulting in the PS1 nanocolumns transforming into nanopeapods composed of nanorods and nanospheres.

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Poly(methyl methacrylate) nanotubes in AAO templates: Designing nanotube thickness and characterizing the T-confinement effect by DSC

Cited by 26 publications

References 143 publications

Effect of Confinement on the Synthesis of PMMA in AAO Templates and Modeling of Free Radical Polymerization

Effect of Confinement on the Synthesis of PMMA in AAO Templates and Modeling of Free Radical Polymerization

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

Replication of Mesoscale Pore One-dimensional Nanostructures: Surface-induced Phase Separation of Polystyrene/Poly(vinyl alcohol) (PS/PVA) Blends

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