Switchable adhesion with a high tuning ratio achieved on polymer surfaces with embedded low-melting-point alloy

2021 ◽  
pp. 101488
Author(s):  
Bo Peng ◽  
Qing-Ao Wang ◽  
Xi-Qiao Feng ◽  
Qunyang Li
Author(s):  
L.H. Bolz ◽  
D.H. Reneker

The attack, on the surface of a polymer, by the atomic, molecular and ionic species that are created in a low pressure electrical discharge in a gas is interesting because: 1) significant interior morphological features may be revealed, 2) dielectric breakdown of polymeric insulation on high voltage power distribution lines involves the attack on the polymer of such species created in a corona discharge, 3) adhesive bonds formed between polymer surfaces subjected to such SDecies are much stronger than bonds between untreated surfaces, 4) the chemical modification of the surface creates a reactive surface to which a thin layer of another polymer may be bonded by glow discharge polymerization.


Author(s):  
Robert C. Rau ◽  
Robert L. Ladd

Recent studies have shown the presence of voids in several face-centered cubic metals after neutron irradiation at elevated temperatures. These voids were found when the irradiation temperature was above 0.3 Tm where Tm is the absolute melting point, and were ascribed to the agglomeration of lattice vacancies resulting from fast neutron generated displacement cascades. The present paper reports the existence of similar voids in the body-centered cubic metals tungsten and molybdenum.


Author(s):  
William Krakow

It has long been known that defects such as stacking faults and voids can be quenched from various alloyed metals heated to near their melting point. Today it is common practice to irradiate samples with various ionic species of rare gases which also form voids containing solidified phases of the same atomic species, e.g. ref. 3. Equivalently, electron irradiation has been used to produce damage events, e.g. ref. 4. Generally all of the above mentioned studies have relied on diffraction contrast to observe the defects produced down to a dimension of perhaps 10 to 20Å. Also all these studies have used ions or electrons which exceeded the damage threshold for knockon events. In the case of higher resolution studies the present author has identified vacancy and interstitial type chain defects in ion irradiated Si and was able to identify both di-interstitial and di-vacancy chains running through the foil.


Author(s):  
Bruno Schueler ◽  
Robert W. Odom

Time-of-flight secondary ion mass spectrometry (TOF-SIMS) provides unique capabilities for elemental and molecular compositional analysis of a wide variety of surfaces. This relatively new technique is finding increasing applications in analyses concerned with determining the chemical composition of various polymer surfaces, identifying the composition of organic and inorganic residues on surfaces and the localization of molecular or structurally significant secondary ions signals from biological tissues. TOF-SIMS analyses are typically performed under low primary ion dose (static SIMS) conditions and hence the secondary ions formed often contain significant structural information.This paper will present an overview of current TOF-SIMS instrumentation with particular emphasis on the stigmatic imaging ion microscope developed in the authors’ laboratory. This discussion will be followed by a presentation of several useful applications of the technique for the characterization of polymer surfaces and biological tissues specimens. Particular attention in these applications will focus on how the analytical problem impacts the performance requirements of the mass spectrometer and vice-versa.


Author(s):  
Quintin J. Lai ◽  
Stuart L. Cooper ◽  
Ralph M. Albrecht

Thrombus formation and embolization are significant problems for blood-contacting biomedical devices. Two major components of thrombi are blood platelets and the plasma protein, fibrinogen. Previous studies have examined interactions of platelets with polymer surfaces, fibrinogen with platelets, and platelets in suspension with spreading platelets attached to surfaces. Correlative microscopic techniques permit light microscopic observations of labeled living platelets, under static or flow conditions, followed by the observation of identical platelets by electron microscopy. Videoenhanced, differential interference contrast (DIC) light microscopy permits high-resolution, real-time imaging of live platelets and their interactions with surfaces. Interference reflection microscopy (IRM) provides information on the focal adhesion of platelets on surfaces. High voltage, transmission electron microscopy (HVEM) allows observation of platelet cytoskeletal structure of whole mount preparations. Low-voltage, high resolution, scanning electron microscopy allows observation of fine surface detail of platelets. Colloidal gold-labeled fibrinogen, used to identify the Gp Ilb/IIIa membrane receptor for fibrinogen, can be detected in all the above microscopies.


2000 ◽  
Vol 10 (PR7) ◽  
pp. Pr7-99-Pr7-102 ◽  
Author(s):  
G. Dosseh ◽  
D. Morineau ◽  
C. Alba-Simionesco
Keyword(s):  

1987 ◽  
Vol 48 (C1) ◽  
pp. C1-495-C1-501 ◽  
Author(s):  
Y. FURUKAWA ◽  
M. YAMAMOTO ◽  
T. KURODA

1985 ◽  
Vol 54 (04) ◽  
pp. 842-848 ◽  
Author(s):  
Kandice Kottke-Marchant ◽  
James M Anderson ◽  
Albert Rabinovitch ◽  
Richard A Huskey ◽  
Roger Herzig

SummaryHeparin is known to affect platelet function in vitro, but little is known about the effect of heparin on the interaction of platelets with polymer surfaces in general, and vascular graft materials in particular. For this reason, the effect of heparin vs. citrate anticoagulation on the interaction of platelets with the vascular graft materials expanded polytetrafluoroethylene (ePTFE), Dacron Bionit (DB) and preclotted Dacron Bionit (DB/PC) was studied in a recirculating, in vitro perfusion system. Platelet activation, as shown by a decrease in platelet count, an increase in platelet release and a decrease in platelet aggregation, was observed for all vascular graft materials tested using heparin and was greater for Dacron and preclotted Dacron than for ePTFE. Significant differences between heparin and citrate anticoagulation were seen for platelet release, platelet aggregation and the relative ranking of material platelet-reactivity. However, the trends and time course of platelet activation were similar with both heparin and citrate for the materials tested.


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