Films FTIR spectroscopy

Infrared spectroscopy, including Fourier-transform infrared (FTIR) spectroscopy, is one of the oldest techniques used for surface analysis. ATR has been used for many years to probe the surface composition of polymers that have been surface-modified by an etching process or by deposition of a film. RAIR has been widely used to characterize thin films on the surfaces of specular reflecting substrates. FTIR has numerous characteristics that make it an appropriate technique for... 

Another illustrative example of the application of FTIR spectroscopy to problems of interest in adhesion science is provided by the work of Taylor and Boerio on plasma polymerized silica-like films as primers for structural adhesive bonding [15]. Mostly these films have been deposited in a microwave reactor using hexamethyldisiloxane (HMDSO) as monomer and oxygen as the carrier gas. Transmission FTIR spectra of HMDSO monomer were characterized by strong... 

The large intrinsic birefringence of the sarcoplasmic reticulum [143] and the polarized attenuated total reflectance FTIR spectroscopy data obtained on oriented films of sarcoplasmic reticulum [144] indicate that a sizeable portion of the secondary structural elements are arranged perpendicularly to the plane of the membrane in a manner reminiscent to the structure of bacteriorhodopsin [145-148]. 

Figure 2. Rates of photodegradation of the copolymer when exposed to a broadband UV source (shortest wavelength 297 nm) (A) change in absorbance as a function of irradiation time in the wavelength range of 250-450 nm (spectrum measured on films) (B) change in absorbance at 3580 cm 1 measured by FTIR spectroscopy (rate of hydroxyl formation)...

FTIR spectroscopy. The ATR-FTIR spectra of the outside surface of the "good" and "bad" white films are shown in Figures 67 and 68, respectively. 

Conclusions. Based on the results of SEM, FTIR spectroscopy, and TGA analyses performed on the "good" and "bad" samples of white packaging film, the brittleness problem reported for the packages appears to have been caused primarily by degradation of the central opaque polyethylene layer. 

Leon, C. R Kador, L. Peng, B. Thelakkat, M. 2006. Characterization of the adsorption of ru-bpy dyes on mesoporous Ti02 films with UV-Vis, Raman, and FTIR spectroscopies. J. Phys. Chem. B 110 8723-8730. 

The dotted line on the left is a bond in a possible precursor trimer. X-ray data suggest an area of 21 3 per alkyl chain, with a thickness of 25 2 A. FTIR spectroscopy suggest that the alkyl chains in -octadecyltrichlorosi-lane SAMs are perpendicular to the surface (Reprinted with permission from [5] A. Ul-man, Introduction to Thin Organic Films From Langmuir-Blodgett to Self Assembly, Academic Press, Boston, 1991. p. 257 and 258. Copyright 1991 Academic Press/Elsevier Science)... 

The use of FTIR to study reaction kinetics and chemical equilibria is based on the disappearance of a v(COO—) vibrational mode of the deprotonated fatty acid in concurrence with the appearance of the v(C=0) mode of the protonated FA. This type of data has been used to support reaction times of a few minutes to several hours or even days. Also, the extent of the reaction has been reported to be stoichiometric (22,23,39,43,47,53), based on the complete disappearance of the v(COO—) vibrational mode, whereas other studies indicate less than 100% conversion (Fig. 3.5.8) of the carboxylate to the protonated form (48,61,66,70). The effect of film structure on reaction rate has been discussed (61,66,70) however, discrepancies of the extent of the reaction of M-FA with H2S have not been previously addressed. FTIR spectroscopy has also been used to determine the effect of film thickness on reaction rate. For example, for 11-, 21-, and 31-layer CdSt films deposited at 37.5 mN in-1, reactions with H2S were found to slop at 42, 78, and 140 h, respectively (66). 

LB film prepared from stearic acid and containing TBTTF-Zn(dmit)2 charge transfer complex (and oxidized by iodine exposure) Absorption, FTIR spectroscopy, lowangle X-ray diffraction, conductivity measurements Maximum conductivities perpendicular and parallel to the LB film were determined to be 10-3Scm-t and4.3xl0 l Scm-1 122... 

Instrumental Methods. Engineers in the IC industry prefer to use X-ray or FTIR spectroscopy to determine the quantities of phosphorus in thin films because of the speed of these methods. These spectroscopic methods are satisfactory for a relative indication of the dopant level in thin films or additives to metallization layers, but they do have serious drawbacks. X-ray spectroscopy is seriously affected by matrix effects and can easily be off by 15-20% of the actual concentration of dopant in thin films if the equipment is not properly calibrated against a material that has been analyzed by wet techniques. X-ray spectroscopy is further affected by the film thickness and the dopant profile throughout the film. 

FTIR spectroscopy is a more accurate method for a quick analysis of the phosphorus in thin films. However, the P205 peak in FTIR is seriously affected if the thin film becomes hydrated. Some loss of sensitivity is caused by the movement of part of the peak from the P205 region to the P205 H20 region upon hydration of the thin film (Figure 3). This shift affects the measured phosphorus content of a thin film. Also, the lack of a significant... 

The determination of specific phosphorus compounds in thin films is important. Only through wet chemical analysis was it possible to first discover the presence and then to accurately measure the quantities of P2Os, P203, and phosphine found in plasma, plasma-enhanced, LPO-LTO (low-pressure oxide-low-temperature oxide), and CVD (chemical vapor deposition) processes (3). Methods such as X-ray or FTIR spectroscopy would have seen all phosphorus atoms and would have characterized them as totally useful phosphorus. In plasma and plasma-enhanced CVD films, phosphine is totally useless in doping processes. 

An interesting technique recently published uses FTIR spectroscopy to detect anions [149]. Thin films of tetraalkylated ferrocenium salts were evaporated onto ATR crystals. Exposure to anion-containing solutions caused incorporation of the anions, and they could then be detected via their IR absorbances. Limits of detection for 10-min analyses varied from 10 6 to 10 s M for a variety of anions however, this technique cannot be used to detect anions that do not have IR absorbances, such as halides. 

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