The transformations of organic polymers during the illumination by 147.0 and 123.6 nm light

Abstract

T h e main features of photolysis of organic polymer-s by t h e light147.0

Vacuum Ultraviolet Photolysis of Hydrocarbon Polymers

“…[7][8][9][10] Since the high energy ($6 to greater than 10 eV) of photons in the VUV spectral range exceeds covalent chemical bond energies found in most polymers ( 5 eV), [11] absorption of the VUV radiation results in bond scission and in the formation of either alkyl or allyl free radicals or both. [12][13][14][15] These can then further react with reactive species in the neighbouring gas phase [16,17] or with one another forming either new chemical functionalities or C C bonds (unsaturation) or both at the polymer surface or a cross-linked network below the surface. [12,14,15,18] VUV photolysis of polymers has been reported extensively in the literature: mass spectrometry [5,12,19,20] and quartz crystal microbalance (QCM) measurements [4,21,22] bear witness to material ablation, whereas infrared spectroscopy (IR), [21,22] radical trapping, [14,15,22] and electron spin resonance (ESR) analysis [13,23] on VUV-irradiated polymer surfaces demonstrated the formation of C C bonds and of radicals.…”

“…[12][13][14][15] These can then further react with reactive species in the neighbouring gas phase [16,17] or with one another forming either new chemical functionalities or C C bonds (unsaturation) or both at the polymer surface or a cross-linked network below the surface. [12,14,15,18] VUV photolysis of polymers has been reported extensively in the literature: mass spectrometry [5,12,19,20] and quartz crystal microbalance (QCM) measurements [4,21,22] bear witness to material ablation, whereas infrared spectroscopy (IR), [21,22] radical trapping, [14,15,22] and electron spin resonance (ESR) analysis [13,23] on VUV-irradiated polymer surfaces demonstrated the formation of C C bonds and of radicals. However, almost all of these investigations were carried out with Summary: The wavelength-dependent vacuum ultraviolet (VUV) photolysis of several polymers, low density polyethylene (LDPE), biaxially oriented poly(propylene) (BOPP), atactic polystyrene (PS), and poly(methyl methacrylate) (PMMA), was studied by irradiation in vacuum with the wellcharacterized emissions from four different resonant or excimer VUV sources.…”

Surface modification of poly(methyl methacrylate) for improved adsorption of wall coating polymers for microchip electrophoresis

“…In particular, the radicals react with O 2 molecules as well as with activated species produced by photolysis, resulting in oxidation of the polymer surface [14]. Therefore, UV irradiation of PMMA causes scission of various chemical bonds in polymer chains including C--C, C--H, C==O, and results in the formation of oxygen-containing species such as carboxylate and hydroxylate groups [24]. HNO 3 is also a rapid oxidizer and likely introduces nitrate groups on the surface of the microchannel.…”

Surface oxidation of cellulose fibers by vacuum ultraviolet irradiation

“…Photooxidation by 123.6 and 147.0 nm radiation in the presence of air was investigated earlier for poly-(methyl methacrylate) and a siloxane rubber. 3,4 Cellulose fibers have been widely utilized for many years as row materials in the production of textile, paper, membrane, and hygiene materials. The surface functionalization of cellulose fibers is also required in some specific applications.…”

“…[1][2][3][4][5] Due to high absorption coefficients (10 4 -10 5 cm Ϫ1 ) of VUV the characteristic depth of VUV penetration for polymers does not exceed a few hundreds nanometer. 4 The energy of VUV photons is enough for scission of any chemical bond including COC, COH, COO, COSi, and COF to produce radicals in the irradiated polymer surface layer. Recombination of the radicals formed by VUV irradiation can result in formation of double bonds and crosslinks in the surface layer.…”