Polymer Brushes as Pressure-Sensitive Automated Microvalves

1994 ◽  
Vol 27 (19) ◽  
pp. 5285-5290 ◽  
Author(s):  
E. M. Sevick ◽  
D. R. M. Williams
Keyword(s):  
Polymer Brushes ◽  
Pressure Sensitive

Pressure-Sensitive Microvalves Made from Polymer Brushes

1994 ◽  
Vol 360 ◽  
Author(s):  
E.M. Sevick ◽  
D.R.M. Williams
Keyword(s):  
Polymer Brushes ◽  
Critical Pressure ◽  
Feedback Mechanism ◽  
Polymer Chains ◽  
Narrow Slit ◽  
Solvent Quality ◽  
Pressure Sensitive ◽  
Wide Range ◽  
Valve Assembly ◽  
Valve Operation

AbstractWe describe a novel microvalve, constructed from polymer chains end-grafted onto opposing surfaces of a narrow slit. The assembly of polymer chains acts as both sensor and valve for microflow control and bypasses the need to construct an external feedback mechanism. This microflow control results from densely grafted chains which repel one another and stretch away from the surface, forming a brush which acts as an elastic and impenetrable layer. The height of a sheared brush increases or decreases depending upon solvent quality, i.e the layer can show a negative Poission's ratio. The discharge through the brushlined conduit is a non-linear function of pressure enabling different modes of valve operation. For brushes which extend moderately into the inter-slit region the valve assembly maintains constant discharge over a wide range of pressure. For brushes which extend far into the inter-slit region the valve assembly cuts off flow above a critical pressure, limiting the maximum discharge.

Visualization of impact force using pressure sensitive paper "Prescale"

2000 ◽  
Vol 10 (PR9) ◽  
pp. Pr9-185-Pr9-190
Author(s):  
K. Ogawa ◽  
T. Yokoyama
Keyword(s):  
Impact Force ◽  
Pressure Sensitive

Forces between asymmetric polymer brushes

1990 ◽  
Vol 51 (8) ◽  
pp. 701-707 ◽  
Author(s):  
D.F.K. Shim ◽  
M. E. Cates
Keyword(s):  
Polymer Brushes

Load-Bearing in the Ovine Medial Tibial Condyle: Effect of Meniscectomy

1993 ◽  
Vol 06 (02) ◽  
pp. 100-104 ◽  
Author(s):  
D. M. Pickles ◽  
C. R. Bellenger
Keyword(s):  
Knee Joint ◽  
Contact Area ◽  
Mammalian Species ◽  
Total Removal ◽  
Load Bearing ◽  
Human Knee ◽  
Biochemical Effects ◽  
Pressure Sensitive ◽  
Medial Meniscectomy ◽  
Tibial Condyle

SummaryTotal removal of a knee joint meniscus is followed by osteoarthritis in many mammalian species. Altered load-bearing has been observed in the human knee following meniscectomy but less is known about biochemical effects of meniscectomy in other species. Using pressure sensitive paper in sheep knee (stifle) joints it was found that, for comparable loads, the load-bearing area on the medial tibial condyle was significantly reduced following medial meniscectomy. Also, for loads of between 50 N and 500 N applied to the whole joint, the slope of the regression of contact area against load was much smaller. Following medial meniscectomy, the ability to increase contact area as load increased was markedly reduced.The load bearing area on the medial tibial condyle was reduced following meniscectomy.

Passivation of pressure sensitive adhesive stickies by addition of acrylic fibers to OCC pulp before papermaking

TAPPI Journal ◽  
2016 ◽  
Vol 15 (10) ◽  
pp. 631-639
Author(s):  
MOHAMMAD HADI ARYAIE MONFARED ◽  
HOSSEIN RESALATI ◽  
ALI GHASEMIAN ◽  
MARTIN A. HUBBE
Keyword(s):  
Adverse Effects ◽  
Control Sample ◽  
Pressure Sensitive Adhesive ◽  
Acrylic Fiber ◽  
Burst Strength ◽  
Pressure Sensitive Adhesives ◽  
Pressure Sensitive ◽  
Tear Index ◽  
Breaking Length ◽  
Acrylic Fibers

This study investigated the addition of acrylic fiber to old corrugated container (OCC) pulp as a possible means of overcoming adverse effects of water-based pressure sensitive adhesives during manufacture of paper or paperboard. Such adhesives can constitute a main source of stickies, which hurt the efficiency of the papermaking process and make tacky spots in the product. The highest amount of acrylic fiber added to recycled pulps generally resulted in a 77% reduction in accepted pulp microstickies. The addition of acrylic fibers also increased pulp freeness, tear index, burst strength, and breaking length, though there was a reduction in screen yield. Hence, in addition to controlling the adverse effects of stickies, the addition of acrylic fibers resulted in the improvement of the mechanical properties of paper compared with a control sample.

Nanostructured Polymer Brushes With Reversibly Changing Properties

2002 ◽  
Vol 727 ◽  
Author(s):  
Denys Usov ◽  
Manfred Stamm ◽  
Sergiy Minko ◽  
Christian Froeck ◽  
Andreas Scholl ◽  
...  
Keyword(s):  
Polymer Brushes ◽  
Phase Segregation ◽  
Water Contact ◽  
Angle Measurements ◽  
Nanostructured Polymer ◽  
Contact Angle Measurements ◽  
Vertical Segregation ◽  
Oxygen Plasma Etching ◽  
Grafting From ◽  
Photoemission Electron

AbstractWe investigated the interplay between different mechanisms of the lateral and vertical segregation in the synthesized via “grafting from” approach symmetric A/B (where A and B are poly(styrene-co-2,3,4,5,6-pentafluorostyrene) and poly(methylmethacrylate), respectively) polymer brushes upon exposure to different solvents. We used X-ray photoemission electron spectroscopy and microscopy (X-PEEM), AFM, water contact angle measurements, and oxygen plasma etching to study morphology of the brushes. The ripple morphology after toluene (nonselective solvent) revealed elongated lamellar-like domains of A and B polymers alternating across the surface. The dimple-A morphology consisting of round clusters of the polymer A was observed after acetone (selective solvent for B). The top layer was enriched with the polymer B showing that the brush underwent both the lateral and vertical phase segregation. A qualitative agreement with predictions of SCF theory was found.

Time response of anodized aluminum pressure-sensitive paint

AIAA Journal ◽  
2001 ◽  
Vol 39 ◽  
pp. 1944-1949
Author(s):  
Hirotaka Sakaue ◽  
John P. Sullivan
Keyword(s):  
Time Response ◽  
Pressure Sensitive Paint ◽  
Anodized Aluminum ◽  
Pressure Sensitive
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