Polymer Characterization Using Singlet Oxygen Phosphorescence as a Spectroscopic Probe

Ogilby, Peter R.; Dillon, M.P.; Gao, Yifei; Iu, Kai-Kong; Kristiansen, M.; Taylor, Vicki L.; Clough, R.L.

doi:10.1021/ba-1993-0236.ch022

Cited by 12 publications

(21 citation statements)

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“…Thus, if possible, it is prudent to measure the same quantity by using several independent techniques. In this study, we determined (j)¿s(acrÍdine) by (1) using a chemical trapping reaction to quantify the amount of 02(axAg) produced per photolysis photon, and (2) comparing the intensity of acridinesensitized 02(axAB) phosphorescence observed from a polystyrene sample to that observed from toluene for which <A\(acridine) is known. Results from the first method are consistent with those obtained from the second method and, upon averaging, yield ¡^(acridine) = 0.56 ± 0.05.…”

Section: Discussionmentioning

confidence: 99%

“…The lowest excited electronic state of molecular oxygen, singlet oxygen (a1Ag), can be produced in solid organic polymers and liquid solvents by several methods, of which photosensitization is the most common. [1][2] In this method, 02(a1Ag) is formed by the transfer of energy from an excited-state donor molecule (i.e., a sensitizer) to groundstate oxygen (X32g-). The excited-state sensitizer is created by photolysis at wavelengths that, depending on the sensitizer, can range from the UV to near-IR.…”

Section: Introductionmentioning

confidence: 99%

“…In an attempt to better understand events that can influence values of in bulk polymers, it is first necessary to systematically quantify absolute yields for the sensitized production of 62(8^) in a solid organic polymer and to compare these data to those recorded in an analogous liquid solvent. Acridine has been extensively studied as a 02<a1Ag) photosensitizer in liquid solutions and is now recommended as a standard for comparative measurements of (>2(8^) yields.3 Acridine has several features Acridine that make it a useful C^ia^g) photosensitizer:27-28 (1) It has an excited-state singlet lifetime short enough to preclude quenching by oxygen. Thus, Acridine is not a precursor to 02(a1Ag).…”

Section: Introductionmentioning

confidence: 99%

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Quantum Yield of Photosensitized Singlet Oxygen (a1.DELTA.g) Production in Solid Polystyrene

Scurlock¹,

Mártire²,

Ogilby³

et al. 1994

Macromolecules

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The quantum yield of singlet oxygen (a1^), produced by energy transfer from the photosensitizer acridine, has been determined by two independent spectroscopic methods in solid polystyrene. Upon 355-nm pulsed-laser irradiation of acridine at 1.3 mJ/pulse, the OzCa1^,) quantum yield in polystyrene [0Aps(acridine) = 0.56 ± 0.05] is slightly smaller than that in a liquid solvent analog such as benzene [0Abera(acridine) = 0.83 ± 0.06]. These data indicate that the photosensitized yields of Oa^A,) in a solid polymer matrix can nevertheless be appreciable, which may be important for understanding the photodegradation of some polymeric materials or of dyes and other additives dissolved in those materials.

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Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Quantum Yield of Photosensitized Singlet Oxygen (a1.DELTA.g) Production in Solid Polystyrene

Scurlock¹,

Mártire²,

Ogilby³

et al. 1994

Macromolecules

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“…On one hand, many polymers are routinely exposed to oxygen‐containing environments, and it is well‐known that oxygen plays a key role in mechanisms of polymer degradation 1, 2. On the other hand, oxygen is a molecule whose presence in a polymer can be used to probe a variety of the polymer's properties, even though the polymer may be designed to work in oxygen deficient applications 3–6. Finally, oxygen itself has many unique properties, and it is of interest to develop oxygen sensors.…”

Section: Introductionmentioning

confidence: 99%

Influence of a novel castor‐oil‐derived additive on the mechanical properties and oxygen diffusivity of polystyrene

Klinger

Tolbod

Ogilby

2010

J of Applied Polymer Sci

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Mechanical properties, densities, and oxygen diffusion coefficients have been measured in polystyrene samples (PS) as a function of additive loading. The additive employed is based on castor oil, and is a desirable alternative to phthalates. Tensile strength measurements indicate the additive renders PS stronger at low loadings, i.e. it antiplasticizes the material. In contrast, the additive plasticizes PS at high loadings. Specific volumes and oxygen diffusion coefficients do not show this dual behavior. Rather, one observes a monotonic decrease in density and oxygen diffusivity with an increase in additive loading. This suggests that the larger segmental motions responsible for the macroscopic properties of the polymer are influenced by the additive in a different manner than the local motions and confined changes in free volume that govern the mobility of oxygen. These data indicate that antiplasticization cannot be predicted solely from diffusivity and density measurements and, vice versa, trends in diffusivity cannot be deduced from mechanical measurements alone.

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“…By extension, interactions between the excited state sensitizer and O 2 (X 3 Σ g − ) will also be susceptible to the magnitudes of the respective diffusion coefficients as determined by the viscosity of the surrounding medium. The effect of these parameters on O 2 (a 1 Δ g ) phosphorescence signals in photosensitized experiments has likewise been examined for sensitizers dissolved in oils and polymers (12,13).…”

Section: Introductionmentioning

confidence: 99%

Time‐resolved Singlet Oxygen Phosphorescence Measurements from Photosensitized Experiments in Single Cells: Effects of Oxygen Diffusion and Oxygen Concentration

Hatz

Poulsen

Ogilby

2008

Photochem & Photobiology

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Time-resolved singlet oxygen, O(2)(a(1)Delta(g)), phosphorescence experiments have been performed in single cells upon pulsed laser irradiation of a photosensitizer incorporated into the cell. Data recorded as a function of the partial pressure of ambient oxygen to which the cell is exposed reflect apparent values for the intracellular oxygen diffusion coefficient and intracellular oxygen concentration that are smaller than those found in neat H(2)O. This conclusion is supported by O(2)(a(1)Delta(g)) phosphorescence data and sensitizer triplet state absorption data recorded in control experiments on sucrose solutions with different viscosities. We recently demonstrated that the intracellular lifetime of O(2)(a(1)Delta(g)) is comparatively long ( approximately 3 micros) and does not differ significantly from that in neat H(2)O ( approximately 3.5 micros). Despite this long lifetime, however, our estimate of an apparent intracellular oxygen diffusion coefficient in the range approximately 2-4 x 10(-6) cm(2) s(-1) means that the spatial domain of intracellular O(2)(a(1)Delta(g)) activity will likely have a spherical radius of approximately 100 nm. This latter point helps reconcile seeming inconsistencies between our direct O(2)(a(1)Delta(g)) lifetime data and results obtained from independent photobleaching experiments that show a limited translational diffusion distance for O(2)(a(1)Delta(g)) within a cell.

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Polymer Characterization Using Singlet Oxygen Phosphorescence as a Spectroscopic Probe

Cited by 12 publications

References 0 publications

Quantum Yield of Photosensitized Singlet Oxygen (a1.DELTA.g) Production in Solid Polystyrene

Quantum Yield of Photosensitized Singlet Oxygen (a1.DELTA.g) Production in Solid Polystyrene

Influence of a novel castor‐oil‐derived additive on the mechanical properties and oxygen diffusivity of polystyrene

Time‐resolved Singlet Oxygen Phosphorescence Measurements from Photosensitized Experiments in Single Cells: Effects of Oxygen Diffusion and Oxygen Concentration

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