Real-time FTIR

Chang SC, Leung LW, Weaver MJ. 1990. Metal crystallinity effects in electrocatalysis as probed by real-time FTIR spectroscopy Electrooxidation of formic acid, methanol, and ethanol on ordered low-index platinum surfaces. J Phys Chem 94 6013-6021. 

The ability of the new precursors to decompose thermally to yield singlephase CIS was investigated by powder XRD analysis and EDS on the nonvolatile solids from the TGA experiments of selected compounds. Furthermore, using TGA-evolved gas analysis (EGA), the volatile components from the degradation of the SSPs could be analyzed via real-time fourier transform infrared (FTIR) and mass spectrometry (MS), thus providing information for the decomposition mechanism.3 The real-time FTIR spectrum for 7 and 8 shows absorptions at approximately 3000,1460,1390,1300, and 1250 cm-1 (see Fig. 6.7). 

Real-Time FTIR. For our IR studies, we utilized a stoichiometrically equivalent amount of a trifunctional thiol, trimethylolpropane tris(2-mercaptoacetate), with a difunctional allyl, trimethylolpropane diallyl ether. The thiols were protected from oxidative polymerization by the addition of hydroquinone. The monomers and hydroquinone were purchased from Aldrich Chemicals and were used as received. This formulation was mixed for five minutes and then a commercial photoinitiator, Esacure TZT (Sartomer Inc.), which contained a blend of methyl benzophenones, was added at a level of 1.0% by weight of monomers to the formulation. Stirring was maintained for a further five minutes following the addition of the photoinitiator. The final formulation contained 2.0% by weight of hydroquinone. The samples were prepared prior to each experiment in order to ensure reproducibility of sample history. 

Figure 8. The extent of reaction as a function of UV exposure time, collected from real-time FTIR, along with the elastic modulus (GO as a function of UV exposure time, measured by the in situ rheological technique, shows that an appreciable elastic modulus appears only after high extents of reactions are reached.

FTIR spectra are also benehcial in establishing the optimum conditions for curing acrylic adhesives by exposure to UV radiation. The degree of UV polymerization of acrylic adhesives can be followed by the decay of the ethylenic ( CH=CH2) absorption band at 810 cm. Scherzer et al. studied the UV-induced crossUnking of a pressure-sensitive acrylic resin with copolymerized benzophenone groups using variable UV doses and intensities. Real time FTIR spectroscopy was also used to study the effect of various photoinitiators in accelerating the photopolymerization of acrylate resins. ... 

Scherzer T, Tauber A, Mehnert R. U.V. curing of pressure-sensitive adhesives studied by real-time FTIR-ATR spectroscopy. Vibrational Spectroscopy. July 2002 Vol. 29(Issues 1-2) 125-131. 

Scherzer T, Decker U. Real time FTIR-ATR spectroscopy to study the kinetics of ultrafast photopolymerization reactions induced by monochromatic UV light. Vibrational Spectroscopy. April 1999 Vol. 19(Issue 2) 385-398. 

In real-time FTIR (RT-FTIR) it is possible to monitor die (slow) film fmmaticxi process as a function of time, but it can also be used to follow the progress of vray fast chemical reactions occurring during film forming, such as curing reactions under the influence of UV [5647]. 

The maximum value of Rp (between 10% and 30% conversion) is one of the reliable parameters to measure the reactivity of the formulation. FTIR profiles also provide the amount of unreacted functional groups remaining in the cured system, which is a parameter that strongly affects the final properties of the polymer. Real-time FTIR is also well suited for dark polymerization reactions that occur immediately after light exposure. One of the disadvantages of this technique appears in composite systems, in which the presence of additives may interfere with the transmission of the light by the polymer system, such as in dental composites. ... 

Figure II. Real-time FTIR waterfall plots of styrene monomer C=C stretch at 1628 cm (top) and =CH2 wag at 907 cm (bottom).

Figure 14. First order kinetic plot for styrene SFRP polymerization at 132 °C (determined from the real-time FTIR profile of the styrene =CH2 absorbance (907 cm )).

Real-time FTIR was used to study the curing of a UV-curable prepolymer (NOA65) and its mixtures with liquid crystals. Curing reactions were examined as a function of film thickness, temperature, and liquid... 

Leung LWH, Weaver MJ (1990) Influence of adsorbed carbon-monoxide on the electrocatalytic oxidation of simple organic-molecules at platinum and palladium electrodes in acidic solution - a survey using real-time FTIR spectroscopy. Langmuir 6 323-333... 

Oiang SC, Ho YH, Weaver MJ (1991) Applications of real-time FTIR spectroscopy to the elucidation of complex electroorganic pathways - electrooxidation of ethylene-glycol on gold, platinum, and nickel in alkaline-solution. J Am Chem Soc 113(25) 9506-9513... 

Extensive studies were carried out in the same time period regarding the structural sensitivity of HCOOH electrooxidation. The rate of formic acid oxidation was highest on Pt(lll), and up to four-fold current enhancement was reported for a 60% (111) oriented surface compared to a polycrystal [23-25]. Interestingly, in contrast to the methanol case, Pt(l 11) exposed to formic acid was less poisoned by COad [26]. Weaver and collaborators compared the structural sensitivity of CH3OH, C2H5OH, and HCOOH electrooxidation on single crystal Pt using real-time FTIR coupled with quasi-steady state voltammetry [27]. This study... 

Near Real-Time FTIR Spectra of Gases from Fast-Heated Compounds... 

P. Gao, S.C. Chang, Z. Zhou, M.J. Weaver, Electrooxidation pathways of simple alcohols at platinum in pure nonaqueous and concentrated aqueous environments as studied by real-time FTIR spectroscopy, J. Electroanal. Chem. 272 (1989) 161-178. 

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