Unusual elastic behavior of ultrathin polymer films: Confinement-induced/molecular stiffening and surface tension effects

2010 ◽  
Vol 132 (18) ◽  
pp. 184902 ◽  
Author(s):  
Shanhong Xu ◽  
Paul A. O’Connell ◽  
Gregory B. McKenna
Keyword(s):  
Surface Tension ◽  
Polymer Films ◽  
Elastic Behavior ◽  
Ultrathin Polymer Films

scholarly journals Properties of PTFE tape as a semipermeable membrane in fluorous reactions

2015 ◽  
Vol 11 ◽  
pp. 980-993 ◽  
Author(s):  
Brendon A Parsons ◽  
Olivia Lin Smith ◽  
Myeong Chae ◽  
Veljko Dragojlovic
Keyword(s):  
Surface Tension ◽  
Organic Compounds ◽  
Polymer Films ◽  
Semipermeable Membrane ◽  
Reaction Vessel ◽  
Dimethyl Phthalate ◽  
Delivery Tube ◽  
Selective Permeability ◽  
Solvent Uptake ◽  
Solvent Adsorption

In a PTFE tape phase-vanishing reaction (PV-PTFE), a delivery tube sealed with PTFE tape is inserted into a vessel which contains the substrate. The reagent diffuses across the PTFE tape barrier into the reaction vessel. PTFE co-polymer films have been found to exhibit selective permeability towards organic compounds, which was affected by the presence of solvents. In this study, we attempted to establish general trends of permeability of PTFE tape to different compounds and to better describe the process of solvent transport in PV-PTFE bromination reactions. Though PTFE tape has been reported as impermeable to some compounds, such as dimethyl phthalate, solvent adsorption to the tape altered its permeability and allowed diffusion through channels of solvent within the PTFE tape. In this case, the solvent-filled pores of the PTFE tape are chemically more akin to the adsorbed solvent rather than to the PTFE fluorous structure. The solvent uptake effect, which was frequently observed in the course of PV-PTFE reactions, can be related to the surface tension of the solvent and the polarity of the solvent relative to the reagent. The lack of pores in bulk PTFE prevents solvents from altering its permeability and, therefore, bulk PTFE is impermeable to most solvents and reagents. However, bromine, which is soluble in liquid fluorous media, diffused through the bulk PTFE. A better understanding of the PTFE phase barrier will make it possible to further optimize the PV-PTFE reaction design.

Surface Viscoelasticity Studies of Ultrathin Polymer Films Using Atomic Force Microscopic Adhesion Measurements

2001 ◽  
Vol 34 (12) ◽  
pp. 4180-4185 ◽  
Author(s):  
X. P. Wang ◽  
Xudong Xiao ◽  
O. K. C. Tsui
Keyword(s):  
Polymer Films ◽  
Atomic Force ◽  
Ultrathin Polymer Films

scholarly journals Stepwise Assembly of Ultrathin Polymer Films

Oleoscience ◽  
2001 ◽  
Vol 1 (9) ◽  
pp. 935-942,926
Author(s):  
Takeshi SERIZAWA ◽  
Mitsuru AKASHI
Keyword(s):  
Polymer Films ◽  
Ultrathin Polymer Films ◽  
Stepwise Assembly

Photochemical Stabilization of Ultrathin Polymer Films Prepared by the Langmuir-Blodgett Technique

1995 ◽  
Vol 28 (7) ◽  
pp. 2537-2543 ◽  
Author(s):  
Takanori Hayashi ◽  
Michiaki Mabuchi ◽  
Masaya Mitsuishi ◽  
Shinzaburo Ito ◽  
Masahide Yamamoto ◽  
...  
Keyword(s):  
Polymer Films ◽  
Langmuir Blodgett ◽  
Ultrathin Polymer Films

Development of Ultrathin Polymer Films and Their Characteristics in Two Dimensions

2005 ◽  
Vol 78 (3) ◽  
pp. 371-382 ◽  
Author(s):  
Shinzaburo Ito ◽  
Michiaki Mabuchi ◽  
Nobuhiro Sato ◽  
Hiroyuki Aoki
Keyword(s):  
Polymer Films ◽  
Two Dimensions ◽  
Ultrathin Polymer Films

Membranes: Ultrathin Polymer Films with Intrinsic Microporosity: Anomalous Solvent Permeation and High Flux Membranes (Adv. Funct. Mater. 30/2014)

2014 ◽  
Vol 24 (30) ◽  
pp. 4728-4728 ◽  
Author(s):  
Patricia Gorgojo ◽  
Santanu Karan ◽  
Him Cheng Wong ◽  
Maria F. Jimenez-Solomon ◽  
João T Cabral ◽  
...  
Keyword(s):  
Polymer Films ◽  
High Flux ◽  
Ultrathin Polymer Films ◽  
Intrinsic Microporosity ◽  
Solvent Permeation
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