نتایج جستجو برای: fluorination Treatment

تعداد نتایج: 1395580  

Cotton fabric was treated with fluorine gas in a nitrogen atmosphere. The effect of fluorination treatments on wettability, whiteness index, dyeability and mechanical properties of cotton fabrics were assessed. Kawabata analysis shows that fluorination treatment increases shear stiffness G, shear hysteresis 2HG5, bending stiffness B and overall fabric stiffness Koshi on cotton fabric. Fluorinat...

2009
Alexander P. Kharitonov Larisa N. Kharitonova

The fundamental features and industrial applications of the direct fluorination of polymers are reviewed. Direct fluorination of polymers (i.e., treatment of a polymer surface with gaseous fluorine mixtures) proceeds spontaneously at room temperature and is a surface modification process. More than 25 polymers have been studied with the aid of a variety of analytical and spectroscopic technique...

Journal: :Journal of Photopolymer Science and Technology 1995

2017
Tsukasa Furuya Takashi Nomoto Tsuyoshi Fukuhara Shoji Hara

We prepared a novel fluorous deoxy-fluorination reagent N,N-diethyl--difluoro-[3,5-bis(1H,1H,2H,2H-perfluorodecyl)benzyl]amine (1b) from 3,5-diiodobenzoic acid (3b) via N,N-diethyl-3,5-bis(1H,1H,2H,2H-perfluorodecyl)benzamide (2b) in four steps and used it for the fluorination of alcohols and diols. After the fluorination reactions, the isolation of the products and recovery of 2b was perfor...

Journal: :Chemistry 2015
Steven Bloom Desta Doro Bume Cody Ross Pitts Thomas Lectka

To expand upon the recent pioneering reports of catalyzed sp(3) C-H fluorination methods, the next rational step is to focus on directing "radical-based fluorination" more effectively. One potential solution entails selective C-C bond activation as a prelude to selective fluorination. Herein, we report the tandem photocatalyzed ring-opening/fluorination reactions of cyclopropanols by 1,2,4,5-te...

Journal: :Journal of prosthodontics : official journal of the American College of Prosthodontists 2016
Stewart W Pharr Erica C Teixeira Ronald Verrett Jeffrey R Piascik

PURPOSE Porcelain chipping has been one of the main problems of porcelain-fused-to-zirconia restorations. This study evaluates the bond strengths of layered, pressed, and adhesively bonded porcelain to yttria-stabilized zirconia substrates that have undergone traditional preparation or gas-phase fluorination. MATERIALS AND METHODS A three-point bending test was used to evaluate the bond stren...

Journal: :Journal of colloid and interface science 2009
Sangyun A Lee Sang Hyup Oh Woojin Lee

To investigate the effect of fluorination on the surface of polydimethylsiloxane (PDMS) film, direct fluorination was performed under a mild condition (approx. 2000 micromol/mol F(2) in nitrogen) for 120 min. No structural damage of PDMS films was observed on the scanning electron microscopic images under the condition. Fourier-transform infrared/attenuated total reflectance (FTIR/ATR) and ener...

Journal: :Journal of the American Chemical Society 2017
Cody Ross Pitts Desta Doro Bume Stefan Andrew Harry Maxime A Siegler Thomas Lectka

In the realm of aliphatic fluorination, the problem of reactivity has been very successfully addressed in recent years. In contrast, the associated problem of selectivity, that is, directing fluorination to specific sites in complex molecules, remains a great, fundamental challenge. In this report, we show that the enone functional group, upon photoexcitation, provides a solution. Based solely ...

2017
Yang'en You Long Zhang Sanzhong Luo

A reagent-controlled enantioselectivity switch was uncovered in the asymmetric a-fluorination of bketocarbonyls by a chiral primary amine catalyst. By a simple swap of fluorination reagents, both enantiomers of the quaternary fluorination adducts could be obtained with good yields and high enantioselectivity. Mechanistic studies disclosed dual H-bonding and electrostatic stereocontrolling modes...

2015
Claudia Struzzi Mattia Scardamaglia Axel Hemberg Luca Petaccia Jean-François Colomer Rony Snyders Carla Bittencourt

Grafting of fluorine species on carbon nanostructures has attracted interest due to the effective modification of physical and chemical properties of the starting materials. Various techniques have been employed to achieve a controlled fluorination yield; however, the effect of contaminants is rarely discussed, although they are often present. In the present work, the fluorination of vertically...

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