Imaging nanostructures on ablated kapton polymide

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.

PAMAM dendrimers in drug delivery: loading efficacy and polymer morphology

2017 ◽  
Vol 95 (9) ◽  
pp. 891-896 ◽  
Author(s):  
P. Chanphai ◽  
L. Bekale ◽  
S. Sanyakamdhorn ◽  
D. Agudelo ◽  
G. Bérubé ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Drug Delivery ◽  
Drug Loading ◽  
Polymer Surface ◽  
Pamam Dendrimers ◽  
Spectroscopic Methods ◽  
Polymer Morphology ◽  
Transmission Electron ◽  
Internal Cavities

The binding efficacy of anticancer drugs doxorubicin and tamoxifen with polyamidoamine (PAMAM-G4) dendrimers was studied in aqueous solution at physiological pH. The results of multiple spectroscopic methods, transmission electron microscopy (TEM), and molecular modeling of conjugated drug–polymer were examined. Structural analysis showed that drug–polymer conjugation occurs mainly via H-bonding and hydrophilic and hydrophobic contacts. Doxorubicin forms a more stable conjugate with PAMAM-G4 than tamoxifen. The drug loading efficacy was 40%–50%. The TEM images showed major changes in the PAMAM morphology upon drug encapsulation. Modeling showed that drug is located in the polymer surface and in the internal cavities. PAMAM nanoparticles are capable of transporting doxorubicin and tamoxifen in vitro. This minireview presents the most recent work performed with the dendrimers demonstrating their usefulness for drug delivery in cancer therapy.

Characterization of Excimer Laser Deposited Gaas Films From the Photolysis of Trimethylgallium and Trimethylarsine At 193 nm

1986 ◽  
Vol 75 ◽  
Author(s):  
V. R. Mccrary ◽  
V. M. Donnelly ◽  
D. Brasen ◽  
A. Appelbaum ◽  
R. C. Farrow
Keyword(s):  
Electron Microscopy ◽  
Excimer Laser ◽  
Deposition Process ◽  
Laser Wavelength ◽  
Time Resolved ◽  
Laser Fluences ◽  
Transmission Electron ◽  
Gaas Films ◽  
193 Nm

AbstractThe growth of GaAs thin films from the excimer laser photolysis of trimethylarsine (TMAs) and trimethylgallium (TMGa) at 193 nm is reported. Scanning electron microscopy (SEM), electron channeling, Rutherford backscattering spectroscopy (RBS), transmission electron microscopy (TEM), and Auger electron spectroscopy (AES) were used to characterize the films. Incident laser fluences on the surface of 0.096–0.115 J/cm2 lead to carbon desorption, adatom mobility, transient annealing and hence epitaxial growth. However, TEM micrographs also revealed the growth of GaAs twins along the <110> direction in a novel periodic fashion, with a spacing equal to that of the ArF excimer laser wavelength (193 nm). Time-resolved mass spectrometry, used to determine gas-phase photolysis products created during the deposition process, showed that AsCH3 and higher gallium-alkyls are significant products which transport As and Ga to the surface.

scholarly journals Natural Infection of Salvia uliginosa with Cucumber Mosaic Cucumovirus

HortScience ◽  
1998 ◽  
Vol 33 (7) ◽  
pp. 1215-1216 ◽  
Author(s):  
G.E. Holcomb ◽  
R.A. Valverde
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Positive Reaction ◽  
Natural Infection ◽  
Particle Morphology ◽  
Transmission Electron ◽  
Cucumber Mosaic Cucumovirus ◽  
Line Patterns

Salvia uliginosa Benth. plants, in an experimental planting of Salvia species, exhibited virus-like symptoms of chlorotic line patterns and ringspots. The suspect virus was mechanically transmitted to several experimental hosts and was identified as cucumber mosaic cucumovirus (CMV) based on dsRNA gel patterns, positive reaction with CMV antiserum, and particle morphology as observed by transmission electron microscopy.

Techniques for Transmission Electron Microscopy of Fiber-Matrix Interfaces in Aluminum Alloy-Boron Composites by Ion Erosio

1971 ◽  
Vol 29 ◽  
pp. 204-205
Author(s):  
G. G. Shaw
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Aluminum Alloy ◽  
Electron Beam ◽  
Pure Aluminum ◽  
Ion Milling ◽  
Transmission Electron ◽  
Fiber Matrix ◽  
Ion Erosion ◽  
Row Of Fibers

The morphology and composition of the fiber-matrix interface can best be studied by transmission electron microscopy and electron diffraction. For some composites satisfactory samples can be prepared by electropolishing. For others such as aluminum alloy-boron composites ion erosion is necessary.When one wishes to examine a specimen with the electron beam perpendicular to the fiber, preparation is as follows: A 1/8 in. disk is cut from the sample with a cylindrical tool by spark machining. Thin slices, 5 mils thick, containing one row of fibers, are then, spark-machined from the disk. After spark machining, the slice is carefully polished with diamond paste until the row of fibers is exposed on each side, as shown in Figure 1.In the case where examination is desired with the electron beam parallel to the fiber, preparation is as follows: Experimental composites are usually 50 mils or less in thickness so an auxiliary holder is necessary during ion milling and for easy transfer to the electron microscope. This holder is pure aluminum sheet, 3 mils thick.

Direct Observation of Heat Exchanger Deposits by Cross Sectioning

1967 ◽  
Vol 25 ◽  
pp. 364-365
Author(s):  
R. W. Anderson ◽  
D. L. Senecal
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Heat Exchanger ◽  
Direct Observation ◽  
Cross Sections ◽  
Preparation Method ◽  
Specimen Preparation ◽  
Flowing Water ◽  
Transmission Electron ◽  
Deposit Layer

A problem was presented to observe the packing densities of deposits of sub-micron corrosion product particles. The deposits were 5-100 mils thick and had formed on the inside surfaces of 3/8 inch diameter Zircaloy-2 heat exchanger tubes. The particles were iron oxides deposited from flowing water and consequently were only weakly bonded. Particular care was required during handling to preserve the original formations of the deposits. The specimen preparation method described below allowed direct observation of cross sections of the deposit layers by transmission electron microscopy.The specimens were short sections of the tubes (about 3 inches long) that were carefully cut from the systems. The insides of the tube sections were first coated with a thin layer of a fluid epoxy resin by dipping. This coating served to impregnate the deposit layer as well as to protect the layer if subsequent handling were required.

Phase Transformations in Ti-7w/oMo-3w/oMe Alloy

1974 ◽  
Vol 32 ◽  
pp. 514-515
Author(s):  
S. Fujishiro
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Transmission Electron Microscopy ◽  
Tensile Strength ◽  
Mechanical Processing ◽  
Ray Method ◽  
X Ray ◽  
Transmission Electron ◽  
Water Quench ◽  
Alpha Beta

The mechanical properties of three titanium alloys (Ti-7Mo-3Al, Ti-7Mo- 3Cu and Ti-7Mo-3Ta) were evaluated as function of: 1) Solutionizing in the beta field and aging, 2) Thermal Mechanical Processing in the beta field and aging, 3) Solutionizing in the alpha + beta field and aging. The samples were isothermally aged in the temperature range 300° to 700*C for 4 to 24 hours, followed by a water quench. Transmission electron microscopy and X-ray method were used to identify the phase formed. All three alloys solutionized at 1050°C (beta field) transformed to martensitic alpha (alpha prime) upon being water quenched. Despite this heavily strained alpha prime, which is characterized by microtwins the tensile strength of the as-quenched alloys is relatively low and the elongation is as high as 30%.

Ultrastructural Analysis of the Salivary Glands of Gromphadorhina Portentosa (Schaum)

1977 ◽  
Vol 35 ◽  
pp. 638-639
Author(s):  
P.J. Dailey
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Salivary Glands ◽  
Secretory Vesicles ◽  
The Past ◽  
Transmission Electron ◽  
Means Of Transmission ◽  
Gromphadorhina Portentosa ◽  
Scanning Electron ◽  
Topographical Relief

The structure of insect salivary glands has been extensively investigated during the past decade; however, none have attempted scanning electron microscopy (SEM) in ultrastructural examinations of these secretory organs. This study correlates fine structure by means of SEM cryofractography with that of thin-sectioned epoxy embedded material observed by means of transmission electron microscopy (TEM).Salivary glands of Gromphadorhina portentosa were excised and immediately submerged in cold (4°C) paraformaldehyde-glutaraldehyde fixative1 for 2 hr, washed and post-fixed in 1 per cent 0s04 in phosphosphate buffer (4°C for 2 hr). After ethanolic dehydration half of the samples were embedded in Epon 812 for TEM and half cryofractured and subsequently critical point dried for SEM. Dried specimens were mounted on aluminum stubs and coated with approximately 150 Å of gold in a cold sputtering apparatus.Figure 1 shows a cryofractured plane through a salivary acinus revealing topographical relief of secretory vesicles.

Two- or three-way observations of the identical cell elements within the same sections by LM, TEM and/or SEM

1978 ◽  
Vol 36 (2) ◽  
pp. 82-83 ◽  
Author(s):  
Nakazo Watari ◽  
Yasuaki Hotta ◽  
Yoshio Mabuchi
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Fine Structure ◽  
Light Microscopy ◽  
Thin Sections ◽  
Transmission Electron ◽  
Identical Cell ◽  
Electron Microscopes ◽  
Scanning Electron

It is very useful if we can observe the identical cell elements within the same sections by light microscopy (LM), transmission electron microscopy (TEM) and/or scanning electron microscopy (SEM) sequentially, because, the cell fine structure can not be indicated by LM, while the color is; on the other hand, the cell fine structure can be very easily observed by EM, although its color properties may not. However, there is one problem in that LM requires thick sections of over 1 μm, while EM needs very thin sections of under 100 nm. Recently, we have developed a new method to observe the same cell elements within the same plastic sections using both light and transmission (conventional or high-voltage) electron microscopes.In this paper, we have developed two new observation methods for the identical cell elements within the same sections, both plastic-embedded and paraffin-embedded, using light microscopy, transmission electron microscopy and/or scanning electron microscopy (Fig. 1).

Transmission Electron Microscopy Studies of Pore Cells in Limax Maximus

1977 ◽  
Vol 35 ◽  
pp. 656-657
Author(s):  
B. S. Beltz
Keyword(s):  
Electron Microscopy ◽  
Cell Periphery ◽  
Salivary Duct ◽  
Terrestrial Mollusc ◽  
Buccal Ganglia ◽  
Transmission Electron ◽  
Pore Cells ◽  
Gland Tissue ◽  
Storage Area ◽  
Limax Maximus

The cells which are described in this study surround the salivary nerve of the terrestrial mollusc, Limax maximus. The salivary system of Limax consists of bilateral glands, ducts, and nerves. The salivary nerves originate at the buccal ganglia, which are situated on the posterior face of the buccal mass, and run along the salivary duct to the gland. The salivary nerve branches several times near the gland, and eventually sends processes into the gland.The pore cells begin to appear at the first large branch point of the salivary nerve, near the gland (Figure 1). They follow the nerve distally and eventually accompany the nerve branches into the gland tissue. The cells are 20-50 microns in diameter and contain very small nuclei (1-5 microns) (Figure 2).The cytoplasm of the pore cells is segregated into a storage area of glycogen and an organelle region located in a band around the cell periphery (Figure 3).

Comparative Microstructures of Ion Milled and Electrochemically Thinned Composite Materials

1974 ◽  
Vol 32 ◽  
pp. 546-547
Author(s):  
R.R. Russell
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Composite Materials ◽  
Great Difficulty ◽  
Ion Milling ◽  
Transmission Electron ◽  
Ion Damage ◽  
Intermetallic Composite

Transmission electron microscopy of metallic/intermetallic composite materials is most challenging since the microscopist typically has great difficulty preparing specimens with uniform electron thin areas in adjacent phases. The application of ion milling for thinning foils from such materials has been quite effective. Although composite specimens prepared by ion milling have yielded much microstructural information, this technique has some inherent drawbacks such as the possible generation of ion damage near sample surfaces.

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