A multitechnique analysis of the outermost layers of the Teflon PFA surface

Piyakis, K.; Sacher, E.; Domingue, A.; Pireaux, Jean‐Jacques; Leclerc, Gervais; Bertrand, Patrick; Lhoest, Jacques

doi:10.1016/0169-4332(94)00551-6

Cited by 12 publications

(4 citation statements)

References 13 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…All treated membranes showed an increase in transmission at ‫ס‬ 2,900 cm −1 (Fig 2, arrow 1), a signal which may be explained by a C-H oscillation. C-H functions of the material were probably caused by an incomplete fluorination of the PTFE structure and were also reported in previous investigations (Tan et al, 1993;Piyakis et al, 1995). An increase in transmission can be explained by a loss of C-H functions indicating that unfluorinated areas are suggested as starting points for chemical reactions.…”

Section: Activation Of Ptfe Surfacessupporting

confidence: 83%

See 1 more Smart Citation

Immobilization of enzymes on PTFE surfaces

Keusgen

Glodek

Milka

et al. 2001

Biotechnol. Bioeng.

View full text Add to dashboard Cite

Membranes and powders prepared from PTFE (polytetrafluorethylene) were investigated for their potential use as multifunctional supports for enzymes. The obtained bioactive materials are valuable for the construction of biosensors and enzyme reactors. To allow covalent coupling of enzymes to PTFE, the surface of the material was treated with elementary sodium followed by oxidation with ozone or hydrogen peroxide.%Derivatization steps were optimized in order to achieve highest enzyme loading and short reaction times. Alliinase (EC 4.4.1.4) and L‐lactic dehydrogenase (EC 1.1.1.27) were chosen as model enzymes and were either immobilized by covalent coupling or fixed indirectly by a sugar‐lectin binding. For the latter method, the sugar mannan was bound to the membrane surface as an anchor for layers of the lectin concanavalin A and the alliinase. Highest alliinase loading was achieved at 0.2 μg×cm−2. Immobilization of alliinase via the lectin concanavalin A and a bifunctional epoxide gave the best long‐term stability.%L‐Lactic dehydrogenase was most sufficiently immobilized by using benzoquinone as spacer. These procedures show several advantages: 1) enzymes can be immobilized under physiological conditions, 2) an enzyme‐multilayer can be achieved, and 3) protein layers are renewable. © 2001 John Wiley & Sons, Inc. Biotechnol Bioeng 72: 530–540, 2001.

show abstract

Section: Activation Of Ptfe Surfacessupporting

confidence: 83%

“…In recent years, some trials were undertaken in order to modify PTFE by chemical methods (Dwight and Riggs, 1974;Tan et al, 1993;Piyakis et al, 1995). It could be demonstrated that a treatment of PTFE surfaces with elementary sodium resulted in carbon-carbon double bonds in concentrations up to 2×10 −6 mol×cm −2 .…”

Section: Introductionmentioning

confidence: 99%

Immobilization of enzymes on PTFE surfaces

Keusgen

Glodek

Milka

et al. 2001

Biotechnol. Bioeng.

View full text Add to dashboard Cite

show abstract

“…Kim et al [32] observed that the autohesion of polyethylene was greatly enhanced by corona treatment, but it was not improved by ozone exposure, although both caused similar surface modifications. A recent study [45] of the PFA surface, using multiple techniques, indicates that the pure PFA sample does not contain mechanically weak boundary layers; instead, its outermost surface is slightly contaminated during manufacture. It is, therefore, possible that these contaminants are incompletely removed by H2 plasma treatment and that they are responsible for the lower adhesion enhancement than was obtained with 02 [13,46].…”

mentioning

confidence: 99%

Fluoropolymer surface modification for enhanced evaporated metal adhesion

Shi¹,

Selmani²,

Martinů

et al. 1994

Journal of Adhesion Science and Technology

Self Cite

View full text Add to dashboard Cite

Adhesion of evaporated Cu to Teflon PFA (polytetrafluoroethylene-co-perfluoroalkoxy vinyl ether) was greatly enhanced by plasma pretreatment. The efficiency of the treatment decreased in the following order: N2 > O2 > (N2 + H2) > (O2 + H2) > H2. X-ray photoelectron spectroscopy (XPS) showed the loss of fluorine and the incorporation of oxygen and nitrogen at the polymer surface. Among the gases, H2 was found to be the most efficient for fluorine elimination, and (N2 + H2) for surface functionalization. Based on this investigation, it is proposed that Cu reacts with both oxygen and nitrogen to form, respectively, Cu-O and Cu-N bonds at the interface but no reaction occurs with carbon and fluorine. While greater enhancement in polymer surface wettability and stronger interfacial reactions can account for the higher performance of N2 over O2 in improving adhesion, these effects cannot explain the lower efficiency of H2. Several possibilities are discussed, including surface cleaning, oxygen incorporation and the formation of weak boundary layers.

show abstract

“…While the ca. 2 nm mean information depth of XPS 34 clearly showed the photoreaction, the 500 nm penetration depth of ATR-IR (at 1000 cm -1 ) 35 did not indicate any change, despite a much better signal to noise ratio.…”

Section: Atr-irmentioning

confidence: 87%

Excimer Laser Induced Surface Photochemical Reaction of 1,2-Diaminoethane with Poly(tetrafluoroethylene)

1997

View full text Add to dashboard Cite

Poly(tetrafluoroethylene) (PTFE or Teflon) is notable for its nonadhesive and nonreactive character. Successful surface photochemical modification of Teflon using liquid 1,2-diaminoethane and λ = 193 nm ArF excimer laser light was demonstrated. The surfaces were analyzed by X-ray photoelectron spectroscopy (XPS), atomic force microscopy, and liquid contact angle and gluing tensile strength measurements. Due to the photomodification the originally poor adhesive property of the PTFE surface was dramatically improved. Surfaces were glued by epoxy resin and the tensile strength of gluing increased by 150 times over that of the unirradiated samples. The surface was metalized electrolessly with silver on selected areas following patterned phototreatment. As a result of the photochemical reaction, hydrophilic and oleophilic property developed on the surfaces at the same time. The water and benzene contact angles decreased from 94° to 40° and from 31° to 0°, respectively. The removal of fluorine and the incorporation of both alkyl groups and nitrogen were identified on XPS spectra. The reaction cross section was determined from water contact angle and XPS results. It was found to be as high as (1.3−1.6) × 10-17 cm2. A radical or a photoinduced electron transfer mechanism is suggested to describe the photoreaction.

show abstract

A multitechnique analysis of the outermost layers of the Teflon PFA surface

Cited by 12 publications

References 13 publications

Immobilization of enzymes on PTFE surfaces

Immobilization of enzymes on PTFE surfaces

Fluoropolymer surface modification for enhanced evaporated metal adhesion

Excimer Laser Induced Surface Photochemical Reaction of 1,2-Diaminoethane with Poly(tetrafluoroethylene)

Contact Info

Product

Resources

About