Model for a UV Laser Based Local Polymer Surface Halogenation Process Using a Gaseous Precursor

Scanning tunneling microscopy (STM) has been used to characterize the surface roughness of nonlinear optical (NLO) polymers. A review of STM of polymer surfaces is included in this volume. The NLO polymers are instrumental in the development of electrooptical waveguide devices, the most fundamental of which is the modulator. The most common modulator design is the Mach Zehnder interferometer, in which the input light is split into two legs and then recombined into a common output within the two dimensional waveguide. A π phase retardation, resulting in total light extinction at the output of the interferometer, can be achieved by changing the refractive index of one leg with respect to the other using the electrooptic effect. For best device performance, it is essential that the NLO polymer exhibit minimal surface roughness in order to reduce light scattering. Scanning tunneling microscopy, with its high lateral and vertical resolution, is capable of quantifying the NLO polymer surface roughness induced by processing. Results are presented below in which STM was used to measure the surface roughness of films produced by spin-coating NLO-active polymers onto silicon substrates.

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Imaging nanostructures on ablated kapton polymide

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100150198 ◽

1993 ◽

Vol 51 ◽

pp. 872-873

Author(s):

Daniel L. Callahan ◽

H. M. Phillips ◽

R. Sauerbrey

Keyword(s):

Electron Microscopy ◽

Polymer Surface ◽

Grating Period ◽

Laser Wavelength ◽

Integrated Devices ◽

Transmission Electron ◽

Excimer Laser Irradiation ◽

Produce Line ◽

Line Patterns ◽

Anisotropic Conduction

Excimer laser irradiation has been used to interferometrically ablate submicron line patterns on to Kapton polyimide. Such patterned material may exhibit highly anisotropic conduction as was predicted from previous studies showing enhanced conductivity from uniformly ablated material. We are currently exploiting this phenomenon to create integrated devices using conventional polymers as both dielectrics and conductors. Extensive scanning electron microscopy (SEM) and limited transmission electron microscopy (TEM) have been conducted in order to characterize the morphology of such patterned nanostructures as a function of processing conditions.The ablation technique employed produces an interference pattern on the polymer surface of period equal to half that of a diffraction grating period, independent of the laser wavelength. In these experiments, a 328 nm grating has been used to produce line patterns of 164 nm line-spacings as shown in Figures 1 and 2. A 200 Å Au coating has been used to both prevent charging and, perhaps more importantly, enhance contrast.

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Imaging of polymer single crystals in low-voltage, high-resolution scanning electron microscopy

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100178665 ◽

1990 ◽

Vol 48 (4) ◽

pp. 1106-1107

Author(s):

W.W. Adams ◽

G. Price ◽

A. Krause

Keyword(s):

Electron Microscopy ◽

Scanning Electron Microscopy ◽

High Resolution ◽

Single Crystals ◽

Low Voltage ◽

Polymer Surface ◽

Beam Current ◽

Image Features ◽

First Results ◽

Scanning Electron

It has been shown that there are numerous advantages in imaging both coated and uncoated polymers in scanning electron microscopy (SEM) at low voltages (LV) from 0.5 to 2.0 keV compared to imaging at conventional voltages of 10 to 20 keV. The disadvantages of LVSEM of degraded resolution and decreased beam current have been overcome with the new generation of field emission gun SEMs. In imaging metal coated polymers in LVSEM beam damage is reduced, contrast is improved, and charging from irregularly shaped features (which may be unevenly coated) is reduced or eliminated. Imaging uncoated polymers in LVSEM allows direct observation of the surface with little or no charging and with no alterations of surface features from the metal coating process required for higher voltage imaging. This is particularly important for high resolution (HR) studies of polymers where it is desired to image features 1 to 10 nm in size. Metal sputter coating techniques produce a 10 - 20 nm film that has its own texture which can obscure topographical features of the original polymer surface. In examining thin, uncoated insulating samples on a conducting substrate at low voltages the effect of sample-beam interactions on image formation and resolution will differ significantly from the effect at higher accelerating voltages. We discuss here sample-beam interactions in single crystals on conducting substrates at low voltages and also present the first results on HRSEM of single crystal morphologies which show some of these effects.

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Studies on the mechanism of printing film-coated tablets containing titanium dioxide in the film by using UV laser irradiation

Drug Development and Industrial Pharmacy ◽

10.1080/03639040903213725 ◽

2009 ◽

Vol 00 (00) ◽

pp. 090915102728058-8

Author(s):

Yoshiteru Kato ◽

Yasuhiko Nakashima ◽

Naoki Shino ◽

Koichi Sasaki ◽

Akihiro Hosokawa ◽

...

Keyword(s):

Titanium Dioxide ◽

Laser Irradiation ◽

Uv Laser

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UV LASER-DRIVEN SHOCK-WAVE EXPERIMENTS AT ULTRAHIGH-PRESSURES UP TO 5 TPa

Le Journal de Physique Colloques ◽

10.1051/jphyscol:1984856 ◽

1984 ◽

Vol 45 (C8) ◽

pp. C8-305-C8-308 ◽

Cited By ~ 1

Author(s):

F. Cottet ◽

M. Hallouin ◽

J. P. Romain ◽

R. Fabbro ◽

B. Faral

Keyword(s):

Shock Wave ◽

Uv Laser

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SPECTRAL CHARACTERIZATION OF REDOX-ACTIVE PRUSSIAN BLUE ON METALLATED PLASMA POLYMER SURFACE MODIFIED CARBON ELECTRODES USING PHOTOTHERMAL DETECTION

Le Journal de Physique Colloques ◽

10.1051/jphyscol:1983645 ◽

1983 ◽

Vol 44 (C6) ◽

pp. C6-285-C6-290 ◽

Cited By ~ 3

Author(s):

J. W. Childers ◽

A. L. Crumbliss ◽

P. S. Lugg ◽

R. A. Palmer ◽

N. Morosoff ◽

...

Keyword(s):

Prussian Blue ◽

Polymer Surface ◽

Spectral Characterization ◽

Plasma Polymer ◽

Carbon Electrodes ◽

Redox Active ◽

Surface Modified

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Binding of Tissue Plasminogen Activator to Vascular Grafts

Thrombosis and Haemostasis ◽

10.1055/s-0038-1646541 ◽

1989 ◽

Vol 61 (01) ◽

pp. 131-136 ◽

Cited By ~ 8

Author(s):

Richard A Harvey ◽

Hugh C Kim ◽

Jonathan Pincus ◽

Stanley Z Trooskin ◽

Josiah N Wilcox ◽

...

Keyword(s):

Plasminogen Activator ◽

Tissue Plasminogen Activator ◽

Fibrinolytic Activity ◽

Polymer Surface ◽

Enzymic Activity ◽

Vascular Prostheses ◽

Chemically Modified ◽

Insoluble Surfactant ◽

Tissue Plasminogen

SummaryTissue plasminogen activator labeled with radioactive iodine (125I-tPA) was immobilized on vascular prostheses chemically modified with a thin coating of water-insoluble surfactant, tridodecylmethylammonium chloride (TDM AC). Surfactant- treated Dacron, polytetrafluoroethylene (PTFE), silastic, polyethylene and polyurethane bound appreciable amounts of 125I- tPA (5-30 μg 125I-tPA/cm2). Upon exposure to human plasma, the amount of 125I-tPA bound to the surface shows an initial drop during the first hour of incubation, followed by a slower, roughly exponential release with a t½ of appoximately 75 hours. Prostheses containing bound tPA show fibrinolytic activity as measured both by lysis of clots formed in vitro, and by hydrolysis of a synthetic polypeptide substrate. Prior to incubation in plasma, tPA bound to a polymer surface has an enzymic activity similar, if not identical to that of the native enzyme in buffered solution. However, exposure to plasma causes a decrease in the fibrinolytic activity of both bound tPA and enzyme released from the surface of the polymer. These data demonstrate that surfactant-treated prostheses can bind tPA, and that these chemically modified devices can act as a slow-release drug delivery system with the potential for reducing prosthesis-induced thromboembolism.

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