l—im—I I um.h-. 00—: WWNHHWUlHHWIJIIWIHIHIHHHWWI 1-53.”: fanfl'xk bi,“ . 4‘21 «41.4th sms‘fét‘.“é‘.M&J ,./ “‘54, J u g f V “I,“ 5?. 9"") «3’ § \é‘if ' ‘ Pi :‘ i. - x 9:3} . . 'W o 1‘: l I' .. "-y l ‘4’ .. v «.2 w V c.» 1: l 1‘3‘k ' "‘_V"I' This is to certify that the thesis entitled Investigations into the nee of o-nitrobenz— aldehyde 1n,polyle£hy1 nethecrylete £11.: 1‘ or ”the inure-out ' our light intensity. presented by Young Cheol Kong has been accepted towards fulfillment of the requirements for H.S . degree in ZOOlOgy Maw Major fiessor Date April 5, 1983 0-7639 MS U is an Affirmative Action/Equal Opportunity Institution )VIESI_J RETURNING MATERIALS: Place in book drop to mummies remove this checkout from .—:3—. your record. FINES will be charged if book is returned after the date stamped below. R on use my“ gags). m§fl~13! fur-9.4994975 55%" ‘ .- ‘ ;. f .j .‘J w 1173‘ la is 'w i has a 5.. 7.;- ..- w E; g; 3.. /€//-- 8 7:37.? INVESTIGATIONS INTo THE USE or O-NITROBENZALDEHYDE IN POLYMETHYL METHACRYLATE FILMS FOR THE MEASUREMENT or LIGHT INTENSITY By Young Cheol Hong A THESIS Submitted to Michigan State University in partial fulfillment of the requirements for the degree of MASTER OF SCIENCE Department of Zoology 1983 ABSTRACT INVESTIGATIONS INTO THE USE OF O-NITROBENZALDEHYDE IN POLYMETHYL METHACRYLATE FILMS FOR THE MEASUREMENT or LIGHT INTENSITY By Young Cheol Hong The measurement of incidental light intensity is one of the most important and fundamental requisites in photochemical studies. Chemical actinometer systems are often used for quantitative photochemical work due to excellent reproducibility, reliability, and convenience. This study was carried out to evaluate the use of o-nitrobenzaldehyde in polymethyl methacrylate films for measuring incidental light intensity. The 0- nitrobenzaldehyde, in the form of polymeric film, undergoes a cumulative photochemical conversion in response to exposure to UV light. The extent of photochemical rearrangement by solar UV light is proportional to the length of exposure. Therefore, this actinometer can cumulatively measure the intensity of incidental UV light without loss of accuracy. Since this actinometer is a thin film, it has an advantage for measuring light intensity at surfaces and locations where currently used devices are normally unsuitable. Therefore, it can be used as a convenient and useful tool to develop better models for photochemical studies, and to better assess the rate at which xenobiotics will react photochemically by solar UV light in the environment. ACKNOWLEDGMENTS I would like to express sincere gratitude to my major professor, Dr. Matthew J. Zabik. I heartily thank you for your guidance and encouragement. The participation of guidance committee members, Dr. Richard Snider and Dr. John Giesy, is also appreciated. ii TABLE OF CONTENTS Page INTRODUCTION 1 EXPERIMENTAL 5 Materials and Methods 5 Reagents 5 Equipment 5 Mercury Decontamination 5 Preparation of Actinometer Films 6 Measurement of Photons Absorbed by a Film 6 Preparation of Calibration Curve for Actinometer Films 11 Effect of Varying Volume of Casting Solution 14 Effect of Angle of Incidental Light 14 Effect of Temperature 19 Effect of Wavelength 28 Effect of Water 32 Measurement of Cumulative Solar Light Intensity 38 Measurement of Solar Light Intensity Using NBA Actinometer Films 39 RESULTS AND DISCUSSION 50 Preparation of Calibration Curve for Actinometer Films 50 Effect of Varying Volume of Casting Solution 50 Effect of Angle of Incidental Light 50 Effect of Temperature 51 iii Page Effect of Wavelength 52 Effect of Water 52 Measurement of Cumulative Solar Light Intensity 53 Measurement of Solar Light Intensity Using Actinometer Films 53 SUMMARY AND CONCLUSIONS 55 LITERATURE CITED 57 APPENDIX 58 iv Table 10 11 LIST OF TABLES Relative Height of the Band at 1530 cm'1 against the mg of NBA per cm2 of Film Relative Height of the Band at 1530 cm"1 against the Thickness of Film The Number of Photons Absorbed by Actinometer Films with Time at 90° Angle of Incidence The Number of Photons Absorbed by Actinometer Films with Time at 60° Angle of Incidence The Number of Photons Absorbed by Actinometer Films with Time at 30° Angle of Incidence The Number of Photons Absorbed by Actinometer Films with Time at 0° (or 180°) Angle of Incidence The Number of Photons Absorbed by Actinometer Films with Time at (4°C (With Exposure to 365 nm) The Number of Photons Absorbed by Actinometer Films with Time at lIOC (Without Irradiation) The Number of Photons Absorbed by Actinometer Films with Time at 37°C (With Exposure to 365 nm) N The Number of Photons Absorbed by Actinometer Films with Time at 37°C (Without Irradiation) The Number of Photons Absorbed by Actinometer Films with Time at 50°C (With Exposure to 365 nm) Page 14 I9 28 31 31 32 35 35 36 36 37 Table Page 12 The Number of Photons Absorbed by Actinometer Films with Time at 50°C (Without Irradiation) 37 13 The Number of Photons Absorbed by Actinometer Films for Wavelength (300 to 400 nm) 38 14 The Number of Photons Absorbed by Actinometer Films with Water (With Exposure to 365 nm) 39 15 The Number of Photons Absorbed by Actinometer Films with Water (Without Irradiation) #2 16 Measurement of Cumulative Solar Light Intensity at 2 PM. on July 6, 1982 #2 17 Measurement of Cumulative Solar Light Intensity at 5 PM. on July 6, 1982 43 18 Measurement of Solar Light Intensity Irradiated on a Tree (at 2.1 m high and East) 43 19 Measurement of Solar Light Intensity Irradiated on a Tree (at 2.1 m high and West) 43 20 Measurement of Solar Light Intensity Irradiated on a Tree (at 2.1 m high and South) at; 21 Measurement of Solar Light Intensity Irradiated on a Tree (at 2.1 m high and North) 44 22 Measurement of Solar Light Intensity Irradiated on a Tree (at 0.6 m high and East) 44 23 Measurement of Solar Light Intensity Irradiated on a Tree (at 0.6 m high and West) It 5 24 Measurement of Solar Light Intensity Irradiated on a Tree (at 0.6 m high and South) #5 vi Table Page 25 Measurement of Solar Light Intensity Irradiated on a Tree (at 0.6 m high and North) 4 5 A-l Relative Height of the Band at 1530 cm"1 versus the mg NBA per cm2 of Film 58 A-2 Relative Height of the Band at 1530 cm"1 versus Volume of Casting Solution 59 A-3 The Number of Photons Absorbed by Actinometer Films with Time at 900 Angle of Incidence 60 A-# The Number of Photons Absorbed by Actinometer Films with Time at 60° Angie of Incidence 61 A-5 The Number of Photons Absorbed by Actinometer Films with Time at 30° Angie of Incidence 62 A-6 The Number of Photons Absorbed by Actinometer Films with Time at 0° (or 180°) Angle of Incidence 63 A-7 The Number of Photons Absorbed by Actinometer Films with Time at #°C (With Exposure to 365 nm) 6!: A-8 The Number of Photons Absorbed by Actinometer Films with Time at l1°C (Without Irradiation) 65 A-9 The Number of Photons Absorbed by Actinometer Films with Time at 37°C (With Exposure to 365 nm) 66 A-10 The Number of Photons Absorbed by Actinometer Films with Time at 37°C (Without Irradiation) 67 A-ll The Number of Photons Absorbed by Actinometer Films with Time at 50°C (With Exposure to 365 nm) 68 A-12 The Number of Photons Absorbed by Actinometer Films with Time at 50°C (Without Irradiation) 69 vii Table A-1 3 A-llt A-l5 A-l6 The Number of Photons Absorbed by Actinometer Films for Wavelength (300 to l400 nm) The Number of Photons Absorbed by Actinometer Films (Control for Wavelength Effect) The Number of Photons Absorbed by Actinometer Films with Water (With Exposure to 365 nm) The Number of Photons Absorbed by Actinometer Films with Water (Without Irradiation) Page 7O 71 72 73 Figure asu¢w 10 ll 12 13 Ill LIST OF FIGURES IR Spectrum of a PMMA Film without o-NBA IR Spectrum of a PMMA Film containing o-NBA Calibration Curve for Actinometer Films Effect of Varying the Volume of Solvent on Casting the Film Irradiation of UV Light to Films Plane Figures on the Area of Films Irradiated at Various Angles of Incidence Effect of Angle of Incidence on Photon Interception by Actinometer Films Effect of Temperature (4°C) on Photon Interception by Actinometer Films Effect of Temperature (37°C) on Photon Interception by Actinometer Films Effect of Temperature (50°C) on Photon Interception by Actinometer Films Effect of Wavelength on Photon Interception by Actinometer Films Effect of Water on Photon Interception by Actinometer Films Measurement of Cumulative Solar Light Intensity by Actinometer Films Measurement of Solar Light Intensity Irradiated on a Tree (at 2.1 m high) by the Actinometer Films ix Page 10 13 l6 l8 I8 21 23 25 27 30 3a #1 (+7 Figure Page 15 Measurement of Solar Light Intensity Irradiated on a Tree (at 0.6 m high) by the Actinometer Films 49 INTRODUCTION Photochemistry is the study of reactions which are caused by reaction (light) either directly or indirectly. Reactions are initiated by electronically excited molecules produced by the absorption of a quanta of suitable radiation typically in the visible and ultraviolet spectral regions. Stark and Einstein (1908—1912) enunciated the second law of photochemistry which states that, "One light-activated molecule is produced by a primary photochemical process, when one single photo (or one quantum of light) is absorbed per molecule of reacting substance which disappears." This law forms the basis of all photochemistry (Giese, 196l1). The quantum yield (6) is used to express efficiency of a photochemical reaction, and is defined as follows (Rohatgi-Mukherjee, 1978): o = number of molecules decomposed or formed per unit time number of quanta absorbed per unit time = number of molecules undergoing that process number of quanta absorbed = rate in the process rate of absorption Appropriate devices for measurement of light intensity are absolutely necessary for quantitative work in photochemical studies and determination of rates in photochemical reactions. Today, photochemists primarily use three devices for measuring light intensity: thermopile-galvanometer systems, phototubes, and chemical actinometer systems (Calvert and Pitts, 1966). Thermopile-galvanometer systems are useful for direct measurement of incidental light intensity over the entire spectral range from visible to far UV 1 2 (200 nm). They have been used for light intensity measurement only at wavelengths where chemical actinometry has not been well developed. Measurements with these systems are very tedious and time consuming, frequently needing calibration against standard radiation sources supplied by the U.S. National Bureau of Standards. Besides, the thermopile is an extremely fragile piece of equipment, necessitating great care when handled (Calvert and Pitts, 1966). Phototubes are good detectors for relative light intensity over a wide range, but are not appropriate for measurement of absolute light intensity. Their non-linear response, poor sensitivity in UV light, and fatigue during operation make them unreliable. Phototubes also must be frequently calibrated against a thermopile-galvanometer system or other standards under similar experimental conditions. They are, therefore, less desirable for quantitative work in a photochemical study (Giese, 1968). Chemical actinometer systems, which utilize reactions of chemicals that decompose with known quantum yields under known experimental conditions, are most useful for rapid and highly accurate determinations of light intensity (Rohatgi-Mukherjee, 1978). Measurements with these actinometer systems are more reliable than those obtained with thermopile-galvanometer systems. In recent years, many chemical actinometer systems (gaseous actinometers and liquid-phase actinometers) have been developed and widely used (Calvert and Pitts, 1966). It has been known that de Saussure made the first chemical actinometer system for measuring light intensity by applying Berthollet's discovery of chlorine water decomposition by sunlight (Giese, 1964). Leighton and Forbes (1930) used a solution of uranyl oxalate to determine quantum yields. Hatchard and Parker (1956) developed a ferrioxalate actinometer system which is very 3 sensitive and constant over a wide range of wavelengths (McLaren, 1964 and Jagger, 1967). The proposed actinometer system in this study is in a solid filmphase, based on Technical Support Package on UV Actinometer Films for NASA (Gupta, Coulbert and Pitts, 1980). A film of polymethyl methacrylate containing 0- nitrobenzaldehyde (NBA) is made by casting from a solution of dichloromethane. Upon absorbing ultraviolet light, photochemically sensitive o-nitrobenzaldehyde undergoes a photochemical rearrangement forming o-nitrosobenzoic acid. Gupta et al. (1980) confirmed that this reaction proceeds when incorporated in a polymeric film and the quantum yield is 0.50 1 0.03. N02 NO hv (sunlight) 7 / CHO COOH Since the extent of this chemical conversion is proportional to time of exposure to UV light, actinometer film can measure cumulative solar UV radiation. This film actinometer system potentially has the following advantages which most devices currently used for measuring incidental light intensity do not have. It can continuously integrate solar UV light intensity in the most interesting wavelength which photochemical studies generally lie (300 to #00 nm). It can be used for measuring incidental UV light accurately on any surface including areas which are normally inaccessible to other instruments. It has a large usable range, approximately up to 5096 conversion of starting material, and has no deleterious effects on rate of photon absorption due to water vapor. It is a not affected by visible light, and is unaffected by a temperature range of 20°C to 50°C. It is inexpensive and easy to use. It can be read conveniently by using an infrared spectrophotometer. This study was performed to evaluate the film actinometer system in relation to its stability, reliability and capability for determination of incidental light intensity. The data obtained from this study will allow one to better assess the rate at which xenobiotics will photoreact in the environment, and to develop models for environmental photochemistry by using the film actinometer system. EXPERIMENTAL MATERIALS AND METHODS Reagents l. o-Nitrobenzaldehyde (NBA): 9896, M.W. 151.12, Aldrich Chemical Company. 2. Polymethyl methacrylate (PMMA): secondary standard, Aldrich Chemical Company. 3. Dichloromethane: Omnisolv for spectroscopy and chromatography, glass distilled, MCB reagent. 4. Nitric acid: diluted with distilled water (1:1). 5. Mercury: acid washed. Equipment 1. Infrared spectrophotometer: Perkin-Elmer 337, and 137 Infracord. 2. UV-Vis spectrophotometer: Gilford 252. 3. Ultraviolet lamp: Blak-Ray UVL-56, 365 nm. 1:. Incubator: Blue M. 5. Petri dish: glass, 13 cm in inside diameter. 6. Slide film holder: cardboard, 5 x 5 cm. 7. Tray: polyethylene, 8" x 6" x 3". Mercury Decontamination Dirty and soiled mercury was placed in a polyethylene tray to expose a large surface area. Diluted nitric acid was added and the two-phase mixture was stirred slowly with a glass rod. After approximately ten minutes, the acid solution was discarded, replaced with fresh acid, and again stirred for ten 6 minutes. After discarding the second acid solution, the mercury was washed three times with distilled water. The mercury was then passed twice, by gravity, through a small pin hole in a filter paper in a glass funnel (Koch and Hanke, 19148). Preparation of Actinometer Films The casting solution was prepared by dissolving 0.05 to 0.1 g of NBA with l g of PMMA in 100 ml of dichloromethane. The casting solution was poured on clean mercury in a Petri dish, which was then covered carefully with a lid so that the casting solution was not disturbed. The dish was allowed to stand until a thin polymer film containing NBA was formed by complete and slow solvent (dichloromethane) evaporation. Using a thin, wide plastic ruler (or metal spatula), the transparent film was carefully lifted off the mercury and cut with scissors into proper size. The film was then inserted into a slide film holder, and both sides were covered with dull black paper to prevent light exposure. One side of the dull black paper was taped on to the holder permitting the system to be opened in a book-like fashion. The film, when mounted in the holder, fitted directly into the sample slot of an IR spectrophotometer. Measurement of Photons Absorbecliy a Film One side of the dull black paper cover was opened, and the film exposed to the sun or experimental light source for a given period. The exposed film was then examined on the IR spectrophotometer and the spectrum was recorded (see Figures 1 and 2). The amount of unreacted NBA in the film was determined by l of the IR spectrum (Meloan, 1963). measuring the height of a band at 1530 cm' The amount of reacted NBA was obtained by subtracting the amount of unreacted NBA from the amount of NBA presented prior to exposure. The number of photons absorbed by the film was determined using the following equation (Gupta, Coulbert and Pitts, 1980): Figure 1. IR Spectrum of a PMMA Film without o—NBA IlIIIlIIIIIIt'I.‘ I II: 62063. Eozmd><>> o a. m.N_L:m.., oo _ 157.23 I. ..... . .0KH 00 1: .i cev .T . .. ..w ..M. ._ e8 . .. L. _ . S ..U.. .I. .1 w 7 008 w ON? .4. .... a . . . _ . . . . 0.. ; V _ . . _ . 0.0 000 00m 009 120 002 oooa 00mm 003 \ $2-0 501:; 3:: <25... < 00 zanmnm E. Figure 2. IR Spectrum of a PM MA Film containing o-NBA 10 000 $206.20 Eozmm><>> _ . . . _ , 00m 002 _.<m30 ZO_._. wIHl0l2_>m<> no Hommmm 9‘? o 17 Figure 5. Irradiation of UV Light to Films Figure 6. Plane Figures on the Area of Films Irradiated at Various Angles of Incidence 18 FIGURES IRRADIATION OF UV LIGHT TO FILMS. L UV LAMPiBGSnm) j '1!"- U) 1.1.] I O z . i ii i/ 329;..— 4 X90. fILM A B C D ANGLE OF 0 ' o o o o INCIDENCE 90 60 3O 0 (I89) FIGURE 6 PLANE FIGURES ON THE AREA OF FILMS IRRADIATED AT VARIOUS ANGLE OF INCIDENCE G= X. _ b = X‘Cosine 30. C = Z'Cosme. .60" 19 were examined by IR spectroscopy to observe changes in height of the absorbance band at 1530 cm'l. The number of photons absorbed by each film was calculated by using equation 1, and results are given in Tables 3, A-3, 4, A-4, 5, A-5, 6, and A-6. A plot of number of photons against time of exposure is shown in Figure 7. This experiment was performed twice. Effect of Temperature 1 A long wavelength (365 nm) UV lamp was used to irradiate films for a given period at selected temperatures: 4°C, 37°C, and 50°C. At respective temperatures, three or four films were irradiated at a 90° angle. The same experiment without UV light was also carried out simultaneously to evaluate film stability at these temperatures. After the films were examined on the IR spectrOphotometer, the amount of reacted NBA was measured and the number of photons absorbed by each film was calculated by using equation 1. Number of photons absorbed versus time was plotted (Figures 8, 9, and 10). Results are given in Tables 7, A-7, 8, A-8, 9, A-9, 10, A-lO, ll, A-ll, 12, and A-12. Table 2. Relative Height of the Band at 1530 cm"1 against the Thickness of Film volume used amount of mg leA per relative heig t for casting, ml PMMA, mg cm of film at 1530 cm' 5 100 0.15 0.60 8 160 0.24 0.61 10 200 10.30 0.74 15 300 0.45 0.69 20 400 0.60 0.65 20 Figure 7. Effect of Angle of Incidence on Photon Interception by Actinometer Films 21 “Limmamomxm no m2: 2 m m e ‘ m _ . _ I. i. > mmmmwmo 00 H To . mmmmwmo on" I . .. mmmmmmo 091 . . mmmmemo email... . (5 FIGURE] fit 1m mmHmZOero/u >m ZO_._.anmm._.z_ _ ZOHOIQ ZO mozm0_oz_ do m302< do Homuuw (,pl x ioaidaodaiNi SNOiOHd 22 Figure 8. Effect of Temperature (4°C) on Photon Interception by Actinometer Films 23 FIGURE 8 232:. 0. m p n \I J O "to C) "d” :5: SOEESI6 Emma :10: EERTI. 202 H04. >m ZG_Hdwomm._.z_ .ZOHOIQ 20 8.3mm3h4ama2wk do Hommmm... OI X) GELdElOtlBLNl SNOLOHd ___1 (LI 24 Figure 9. Effect of Temperature (37°C) on Photon Interception by Actinometer Films 25 FIGURE 9 25mg; cI—N C: (I 9.9 CD 0> —w G ~q- H103 0001.23" @1110 “Ecmwmthoj 1:3" I -m— .3 il a? IzoEmommHz. 2901.. 20 Skeweaémnzmz. noIIIiannm (pm GaidaoaaiNi SNOLOHd 26 Figure 10. Effect of Temperature (50°C) on Photon Interception by Actinometer Films 27 FLGURE IO t; EEC. (5" CD 0 _ 1’9 cl... Em: Sort? olld 15895915.? Ti. fit m3... mmemzongsm‘ 293889; 20516. 20 8.0mmmaammn2me no Swim (,pixmaidaoaaiui SNOIOHd 28 Effect of Wavelength Films were inserted into the sample slot of a UV-Vis spectrOphotometer, and irradiated at various wavelengths for four hours. Wavelengths at 10 nm intervals from 300 nm to 400 nm were used for this experiment. This experiment was carried out twice at each wavelength. Films stored at room temperature without irradiation were used as control for the irradiated films. After four hours of irradiation, films were examined by IR spectrosc0py, and amount of reacted NBA was determined. Using equation 1, the number of photons absorbed was calculated and wavelength versus number of photons was plotted (Figure 11). Results are given in Tables 13, A-13, and A-14. Table 3. ms Number of Photons Absorbed by Actinometer Films with Time at 90 Angle of Incidence amount of N A time, hr reacted, mg/cm film photons (x1017) 1/2 0.1117 8.91 1 0.1376 10.97 2 0.1757 14.01 3 0.2014 16.06 5 0.2210 17.62 7 0.2437 19.43 10 0.2547 20.31 29 Figure 11. Effect of Wavelength on Photon Interception by Actinometer Films 30 12:5 Ihwzw4m><3 FIGUREII C ooe 0mm 0mm 0mm owm 0m... 9.6m own own 0.5 com _ . 9:28 .. -N I!!! IN. .iN ..... 1...... ....... ii... .i.... 1e -m 10 mZJE mmHmZOZPQq >m ZO_._.Qmomm._.Z_ ZOHOIQ ZO Ihozw4m><>>mo hommnm SI ( OIX) GBLdBOHBiNI SNOLOHd 31 Table 4. Th8 Number of Photons Absorbed by Actinometer Films with Time at 60 Angle of Incidence amount of N A time, hr reacted, mg/cm film photons (x1017) 1/2 0.0473 3.77 1 0.0927 7.39 2 0.1420 11.32 3 0.1654 13.19 5 0.1839 14.66 7 0.1978 15.77 10 0.2127 16.96 Table 5. The) Number of Photons Absorbed by Actinometer Films with Time at 30 Angle of Incidence amount of N A time, hr reacted, mg/cm film photons (x1017) 1/2 0.0316 2.52 1 0.0630 5.02 2 0.0949 7.57 3 0.1134 9.04 5 0.1382 11.02 7 0.1505 12.00 10 0.1658 13.22 32 Table 6. The Number of Photons Absorbed by Actinometer Films with Time at 0 c (or 180°) Angie of Incidence amount of N A time, hr reacted, mg/cm film photons (x1017) 1/2 0.0143 1.14 1 0.0138 1.10 2 0.0243 1.94 3 0.0413 3.29 5 0.0458 3.65 7 0.0536 4.27 10 0.0647 5.16 Effect of Water About one ml of distilled water was applied on films, and afterward irradiated with UV light by using a long wavelength (365 nm) UV lamp for a given period of time. Exposed films were then examined by IR spectrosc0py and the number of photons absorbed by the films was calculated. Films without irradiation were used as control for irradiated films and also examined by IR spectroscopy. Three films were used for irradiation of each run in this experiment. A plot of number of photons absorbed versus time is shown in Figure 12, and results are given in Tables 14, A-15, 15, and A-l6. 33 Figure 12. Effect of Water on Photon Interception by Actinometer Films 34 FIGUREIZ -O Tfmzi. O ~0 ZO_.Em0mm._.Z_ 20.510 20 mum/x3 no Hommum SNOLOHd (“01 x ioaidaodaiNi 35 Table 7. Tge Number of Photons Absorbed by Actinometer Films with Time at 4 C (With Exposure to 365 nm) amount of N A time, hr reacted, mg/cm film photons (x1017) 1/2 0.0110 0.88 1 0.0221 1.77 2 0.0339 2.70 4 0.1135 9.05 6 0.1175 9.37 8 0.1239 9.88 10 0.1610 12.83 Table 8. The Number of Photons Absorbed by Actinometer Films with Time at 4° C (Without Irradiation) amount of N A time, hr reacted, mg/cm film photons (x1017) 1/2 0.0013 0.10 1 0.0028 0.23 2 0.0029 0.23 4 0.0067 0.53 6 0.0065 0.52 8 0.0082 0.65 10 0.0055 0.44 36 Table 9. Tbs Number of Photons Absorbed by Actinometer Films with Time at 37 C (With Exposure to 365 nm) amount of N A time, hr reacted, mg/cm film photons (x1017) 1/2 0.0192 1.53 1 0.0352 2.81 2 0.0865 6.90 4 0.1280 10.21 6 0.1473 11.75 8 0.1568 12.50 10 0.1612 12.85 Table 10. The [Plumber of Photons Absorbed by Actinometer Films with Time at 37 C (Without Irradiation) amount of N A time, hr reacted, mg/cm film photons (x1017) 1/2 0.0020 0.16 1 0.0024 0.19 2 0.0022 0.18 4 0.0040 0.32 6 0.0052 0.41 8 0.0035 0.28 10 0.0048 0.38 37 Table 11. The Number of Photons Absorbed by Actinometer Films with Time at 50° C (With Exposure to 365 nm) amount of NQA time, hr reacted, mg/cm film photons (x1017) 1/2 0.0246 1.96 2 0.0667 5.32 4 0.0948 7.56 6 0.1367 10.90 8 0.1636 13.04 10 0.1653 13.18 Table 12. The Number of Photons Absorbed by Actinometer Films with Time at 50° C (Without Irradiation) amount of N A time, hr reacted, mg/cm film photons (x1017) 1/2 0.0022 0.17 2 0.0018 0. l5 4 0.0030 0.24 6 0.0028 0.22 8 0.0029 0.23 10 0.0035 0.28 38 Table 13. The Number of Photons Absorbed by Actinometer Films for Wavelength (300 to 400 nm) amount of N A wavelength, nrn reacted, mg/cm film photons (x1016) 300 0.0018 1.42 310 0.0037 2.94 320 0.0016 1.30 330 0.0093 7.38 340 0.0026 2.08 350 0.0017 1.39 360 0.0107 8.54 370 0.0036 2.89 380 0.0055 4.38 390 0.0018 1.46 400 0.0017 1.39 control film 0.0035 2.80 Measurement of Cumulative Solar Light Intensity An actinometer film was exposed to sunlight for a given period of time on July 6, 1982 (location: Lansing, Michigan). After examining the film on the IR spectrOphotometer, the film was again exposed to sunlight under the same 2 conditions. Two films with different concentration of NBA/cm film were used to perform this experiment at two different times (2 P.M. and 5 P.M.) on the same day. The number of photons absorbed by the film each time was determined by using equation 1, and a plot of the number of photons absorbed 39 versus time of exposure is shown in Figure 13. The correlation coefficient of the determinations by linear regression was obtained using a curve fitting program on a Hewlett-Packard 97 calculator. Results are given in Tables 16 and 17. Measurement of Solar Light Intensitj UsinLNBA Actinometer Films A 2.7 m tall and 1.8 m wide round-shaped honeysuckle (Lonicera tatarica) which stood solitarily in the middle of a field at the Michigan Department of Public Health, Lansing, Michigan was selected for this purpose. Actinometer films (approximately 0.3 mg NBA/cm2 film) were vertically hung on leaves of the bush at four different directions (east, west, south, and north), and at two different heights (2.1 m and 0.6 m). They were exposed to sunlight for ten minute periods at four different times of the day (10 A.M., 12 Noon, 2 P.M., and 4 P.M. on August 12, 1982). After examining the films by IR spectroscopy, the number of photons absorbed by the films was calculated by using equation 1. Results are given in Tables 18, 19, 20, 21, 22, 23, 24, and 25. The plots of photons absorbed by each film versus time of exposure are shown in Figures 14 and 15. Table 14. The Number of Photons Absorbed by Actinometer Films with Water (With Exposure to 365 nm) amount of N A time, hr reacted, mg/cm film photons (x1017) 1/2 0.0477 3.80 1 0.0324 2.58 2 0.0634 5.06 4 0.0620 4.94 6 0.0764 6.09 8 0.1336 10.65 10 0.1433 11.42 40 Figure 13. Measurement of Cumulative Solar Light Intensity by Actinometer Films 41 13:5 V memomxm mod—2; flGURElB 0.6 0% ow. Q .55 m E . . . 2.5%... $.on 24:61.6 . 1 .53 N .2. . 2535 8.02 24:811.. v .. aommox . 1 a. 90% (“01x1 SNOLOHd fin: 1N— anm mmeZOZfium Hm >._._mzmHZ_ H103 m<40wlm>rr<42>3d mo ._.21 Emmawxxmz 42 Table 15. The Number of Photons Absorbed by Actinometer Films with Water (Without Irradiation) amount of N A time, hr reacted, m g/cm film photons (x1017) 1/2 ----- ---- 1 ...... ---- 2 0.0058 0 . 4 5 4 ------ ..-_ 5 ....--- ---- 8 0.0027 0 . 21 10 0.0058 0 . 45 Table 16. Measurement of Cumulative Solar Light Intensity at 2 P.M. on July 6, 1982 - time, height of barid amount of NBA 2 amount of NBA2 photops minutes at 1530 cm' ) remained, mg/cm reacted, mg/cm (x10 0 0.720 0.3039 5 0.665 0.2807 10 0.640 0.2701 20 0.570 0.2406 40 0.465 0.1963 60 0.400 0.1688 0.0232 0.0338 0.0633 0.1076 0.1351 1.85 2.69 5.04 8.58 10.76 43 Measurement of Cumulative Solar Light Intensity at 5 P.M. on July 6, 1982 Table 17. amount of NBA time, height of bar‘d remained, mg/cm amount of NB phot 5 minutes at 1530 cm' 2 A2 Y9) reacted, m g/cm (x 10 0 0.650 0.2622 ---- ..... 5 0.615 0.2481 0.0141 1.12 10 0.590 0.2380 0.0242 1. 93 20 0.530 0.2138 0.0484 3 . 86 40 0.445 0.1795 0.0827 6 . 59 60 0.385 0.1553 0.1069 8.52 Table 18. Measurement of Solar Light Intensity Irradiated on a Tree (at 2.1 m high and East) amount of N A 17 time reacted, mg/cm film photons (x10 ) 10 A.M. 0.0675 5.38 12 Noon 0.0676 5.39 2 P.M. 0.0123 0.98 4 P.M. 0.0061 0.49 Table 19. Measurement of Solar Light Intensity Irradiated on a Tree (at 2.1 m high and West) amount of N A 17 time reacted, mg/cm film photons (x10 ) 10 A.M. 0.0020 0.16 12 Noon 0.0031 0.25 2 P.M. 0.0061 0.49 4 P.M. 0.0140 1.12 cm Table 20. Measurement of Solar Light Intensity Irradiated on a Tree (at 2.1 m high and South) amount of N A 17 time reacted, mg/cm film photons (x10 ) 10 AM. 0.0324 2.58 12 Noon 0.0551 4.39 2 P.M. 0.0810 6.46 4 P.M. 0.0762 6.08 Table 21. Measurement of Solar Light Intensity Irradiated on a Tree (at 2.1 m high and North) amount of N A 17 time reacted, mg/cm film photons (x10 ) 10 AM. 0.0250 1.99 12 Noon 0.0375 2.99 2 P.M. 0.0188 1.50 4 P.M. 0.0094 0.75 Table 22. Measurement of Solar Light Intensity Irradiated on a Tree (at 0.6 m high and East) amount of N 17 time reacted, mg/cm photons (x10 ) 10 A.M. 0.0438 3.49 12 Noon 0.0375 2.99 2 P.M. 0.0031 0.25 4 P.M. 0.0031 0.25 45 Table 23. Measurement of Solar Light Intensity Irradiated on a Tree (at 0.6 m high and West) amount of N A 17 time reacted, mg/cm film photons (x10 ) 10 AM. 0.0031 0.25 12 Noon 0.0033 0.27 2 P.M. 0.0100 0.80 4 P.M. ---- --- Table 24. Measurement of Solar Light Intensity Irradiated on a Tree (at 0.6 m high and South) amount of N A 17 time reacted, mg/cm film photons (x10 ) 10 AM. 0.0032 0.26 12 Noon 0.129 1.03 2 P.M. 0.0385 3.07 4 P.M. 0.0726 5.79 Table 25. Measurement of Solar Light Intensity Irradiated on a Tree (at 0.6 m high and North) amount of N A 17 time reacted, mg/cm film photons (x10 ) 10 AM. 0.0032 0.26 12 Noon 0.0032 0.26 2 P.M. --‘-- u--- 4 P.M. 0.0061 0.49 46 Figure 14. Measurement of Solar Light Intensity Irradiated on a Tree (at 2.1 m high) by the Actinometer Films 47 Eat. in? SAN zoozw. .2.._._wzm.rz_ .503 mm :55 218.0 SEE < 20 n5 HzmzmmDm/‘mz 991x13N010Hd RESULTS AND DISCUSSION Preparation of Calibration Curve for Actinometer Films Gupta et al. (1980) have shown that calibration curves for orthonitrobenzaldehyde actinometer films have excellent linearity. From the linear regression calculations, the calibration curve for actinometer films has very good linearity with r = 0.9997. These results show that the absorbance at 1530 cm'1 is proportional to the concentration of NBA in the film (mg/cm2 film). Thus, the concentration of NBA in a film can be obtained easily from this linear calibration curve, after measuring the height of the IR band at 1530 cm'l. Effect of Varying Volume of Casting Solution Of the five respective volumes evaluated, the 10 ml casting solution, containing 200 mg of PMMA, showed the highest absorbance band at 1530 cm'l. The absorbance band at 1530 cm'1 from the larger volume of casting solution tends to be interfered with more than that from the smaller volume, due to an increase in intensity and overlap of adjacent bands from the polymer. The best results were obtained from films containing 0.3 mg NBA per cm2 of film and 200 mg of PMMA. Effect of Angle of Incidental Light Assuming that the length (x) of a film exposed to light as shown in Figure 6 is 1 cm, the area of the incidental light which had fallen on the film at 900 angle is the same as the area of the film (1 x 1 cm2) because the incidental light falls directly on the whole length (1 cm) of the film. However, at 60° angle of 50 51 incidence, the area of the incidental light which falls on the film becomes smaller than that at 90° angle of incidence, due to the oblique angle of the film to the light. The length (b in Figure 6) of the incidental light which had fallen on the film at 60° angle is actually equal to the cosine 30° (= 0.866 cm). In the same manner, a 300 angle of incidence is equal to cosine 60° (= 0.5 cm). Therefore, the area of the incidental light for a 90° angle of incidence is 1 x 1 cm2, l x 0.866 cm2 2 for a 60°, and 1 x 0.5 cm for a 30° angle of incidence. The ratio of the area of the incidental light which had fallen on the film at various angles of incidence of 90°: 60°: 30° equals 1: 0.87 : 0.5, respectively. From the results as shown in Tables 3, 4, and 5, the number of photons absorbed by a film in 3 hours was 16.06 x 1017 at 90° angle, 13.19 x 1017 at 60° 17 at 30° angle by which the ratio of the number of photons angle, and 9.04 x 10 absorbed by each film was 1 : 0.82 : 0.56. Again, the number of photons absorbed in 10 hours at 90°, 60°, and 30° angle of incidence was 20.31 x 10”, 16.96 x 1017, and 13.22 x 1017, respectively, and gives the ratio of 1 : 0.84 : 0.65. These experiments show that the number of photons absorbed by films depends on the area (quantity) of incidental light which has fallen on the film, and angle of incidence has an effect on the absorption of the number of photons by film, due to changes in area of incidental light. Effect of Temperature Without irradiation, the actinometer films were little affected by the various temperatures (4°C, 37°C, and 50°C) for the three experiments. Chemical conversion by photochemical reaction which occurred at all temperatures had equal rates and photon absorption. These experiments demonstrate that actinometer films are not sensitive to variations of temperature from 4°C to 50°C, and that temperature has little influence on the stability and capability of films to measure photons produced by 52 various wavelengths of light. It is well known that temperature has little or no effect on primary photochemical reactions, but has a marked effect on secondary reactions, since the secondary processes are thermal reactions (Ellis, 1941). Therefore, they may be used as a stable and reliable device for measuring photons caused by a primary photoreaction at these temperatures. Effect of Wavelength As shown in Figure 11, films generally reflected an insensitivity of response to a variation in wavelength except wavelengths at 330 nm and 360 nm which had conspicuous effect on the actinometer films. Of ten respective wavelengths evaluated, the wavelength at 360 nm had the greatest effect on photochemical conversion of o-nitrobenzaldehyde in a film. Thus, it is likely that an effective wavelength for the NBA film actinometer lies in the range of 320 nm and 380 nm. Effect of Water Without irradiation, water had little effect on the stability of actinometer films. With irradiation of UV light, water had an effect on the absorption of UV incidental light by actinometer films as shown in Figure 12. The films irradiated for less than five hours gave a fluctuation in the absorption of photons versus time. However, comparing with the results from effect of angle of incidence, films irradiated from six to ten hours gave an effect similar to films which were irradiated in the absence of water. The long irradiation caused the vaporization of the distilled water which had been applied to the films. This was due to the heat produced by the UV lamp. This experiment shows that water interferes with the absorption of incidental light by preventing some light from reaching the films. 53 Measurement of Cumulative Solar Light Intensity As shown in Figure 13, the correlation coefficient of plots of photons absorbed versus time of exposure was 0.9915 for film A (0.3 mg NBA/cm2 film), and 0.9920 for film B (0.26 mg NBA/cmz film), respectively. Thus, these results show that the plots of the determinations (photons absorbed versus time of exposure) have good linearity, and that the concentration of NBA in films has little effect on the rate of photochemical conversion of o-nitrobenzaldehyde by solar UV light. Therefore, o-nitrobenzaldehyde in a film is cumulatively altered by exposure to sunlight, and the extent of photochemical conversion of NBA depends on length of exposure. This experiment demonstrates that the actinometer films can measure continuously the intensity of solar UV light. It has been reported by Gupta et al. (1980) that the o-nitrobenzaldehyde films have a linear range of up to about 5096 conversion by photoreaction. Thus, they may be used for measuring cumulatively the intensity of solar UV light until 5096 conversion of initial amount of NBA in films occurs. Measurement of Solar Light Intensitj Using Actinometer Films In the morning (10 AM. and 12 Noon), the strongest light intensity was measured from the films at the east side, and the intensity of light then faded as time progressed. In the afternoon (2 P.M. and 4 P.M.), the strongest intensity of sunlight was absorbed by the films on the southern part, and the lowest intensity of light was detected from those films at the west side even though the sun had moved westward. At 2.1 m high, the greatest absorption of incidental light by the actinometer films was observed, and the smallest absorption occurred at 0.6 m of height. 54 Again, this experiment shows that actinometer films are capable of measuring solar UV light intensity in obedience to the intensity of incidental light which has fallen on the films. SUMMARY AND CONCLUSIONS The following results were derived from this study on the o- nitrobenzaldehyde film actinometer system: 1. Film actinometer can be easily prepared by casting from dichloromethane containing polymethyl methacrylate. 2. It is stable at a temperature range of 4°C to 50°C. 3. Angle of incidence has an effect on the absorption of the number of photons by film actinometer. 4. The most effective range in wavelengths for film actinometer lies between 320 nm and 380 nm. 5. Water interferes with the absorption of incidental light by film actinometer. 6. Film actinometer can continuously measure solar UV light without loss of accuracy up to 5096 depletion of initial amount of o- nitrobenzaldehyde. 7. Film actinometer can be used for determination of incidental light intensity at any surface and locations to which currently used devices are normally inaccessible. 8. Determination of photons absorbed by films can be obtained conveniently by using an IR spectrOphotometer. Therefore, the film actinometer system may be used as a convenient, useful tool for measuring incidental light intensity to develop better models for 55 56 photochemical studies, and to better assess the rate at which xenobiotics will react by solar UV light in the environment. LITERATURE CITED LITERATURE CITED Calvert, J. G., and Pitts, J. N. (1966). Photochemistry, John Wiley & Sons, Inc., 686 pp. Ellis, C., and Wells, A. A. (1941). The Chemical Action of UV Rays, Reinhold Publishing Corporation, N. Y., 248 pp. Giese, A. C. (1964). Photophysiology, Vol. 1, Academic Press, 1-29. Giese, A. C. (1968). Photophysiology, Vol. 3, Academic Press, 1-20. Gupta, A., Coulbert, C. D., and Pitts, J. N. (1980). Technical Support Package on UV Actinometer Films, NASA TECH. BRIEF, Vol. 5, No. 2, Item 27, 1-9. Hatchard, C. G., and Parker, C. A. (1956). Proc. Roy. Soc., A235, 518 pp. Jagger, J. (1967). Introduction to Research in Ultraviolet Photobiology, Prentice-Hall, Englewood Cliffs, New Jersey, 137 pp. Koch, F. C., and Hanke, M. E. (1948). Practical Methods in Biochemistry, The Williams 6: Wilkins Company, 380-382. Leighton, W. G., and Forbes, G. S. (1930). J. Amer. Chem. Soc. 52, 3139 pp. McLaren, A. D., and Shugar, D. (1964). Photochemistry of Proteins and Nucleic Acids, Pergamon, Oxford, 376-384. Meloan, C. E. (1963). Elementary Infrared Spectroscopy, Macmillan Co., 166 pp. Rohatgi-Mukherjee, K. K. (1978). Fundamentals of Photochemistry, John Wiley 6: Sons, Inc., 5-6 6: 298-302. 57 APPENDIX 58 1 Table A-1. Relftive Height of the Band at 1530 cm' versus the mg NBA per cm of Film mg NIBA per relative band height at 1530 cm'1 cm film 1 2 2 4 0.10 0.390 0.345 0.385 0.400 0.15 0.470 0.475 0.478 0.425 0.20 0.505 0.575 0.550 0.538 0.25 0.625 0.600 0.645 0.650 0. 30 0.700 0.690 0.715 0.755 59 1 Table A-2. Relative Height of the Band at 1530 cm' versus Volume of Casting Solution 1 volume of casting relative band height at 1530 cm' solution, ml 1 2 3 4 5 0.585 0.600 0.620 0.585 8 0.570 0.635 0.625 0.600 10 0.700 0.730 0.775 0.745 15 0.690 0.705 0.715 0.645 20 0.635 0.660 0.700 0.610 60 Table A-3. The Numbgr of Photons Absorbed by Actinometer Films with Time at 90 Angle of Incidence amount of NB; unreacted amount of NBA reacted time, hr mg/cm film mg/cm film photons (x10”) ”2 0.2480 0.1020 8.13 0.2284 0.1216 9.69 1 0.2065 0.1435 11.44 0.2184 0.1316 10.49 2 0.1724 0.1776 14.16 0.1763 0.1737 13.85 3 0.1518 0.1982 15.80 0.1454 0.2046 16.31 5 0.1295 0.2205 17.58 0.1286 0.2214 17.66 7 0.0956 0.2544 20 . 29 0.1171 0.2329 18.57 10 0.0940 0.2560 20.40 0.0963 0.2537 20.21 61 Table A-4. The Numbgr of Photons Absorbed by Actinometer Films with Time at 60 Angle of Incidence amount of N unreacted amount of NBA reacted 17 time, hr mg/cm film mg/cm film photons (x10 ) ”2 0.2426 0.0574 4. 58 0.2630 0.0370 2 . 95 1 0.2117 0.0883 7.04 0.2029 0.0971 7.74 2 0.1735 0.1265 10.09 0.1427 0.1573 12 . 55 3 0.1402 0.1598 12. 74 0.1289 0.1711 13.64 5 0.1201 0.1799 14.34 0.1123 0.1877 14.97 7 0.1066 0.1934 15.42 0.0979 0.2021 16. 12 10 0.0938 0.2062 16. 44 0.0808 0.2192 17.47 62 Table A-5. The Numbgr of Photons Absorbed by Actinometer Films with Time at 30 Angle of Incidence amount of NB; unreacted amount of NBA reacted time, hr mg/cm film mg/cm film photons (x10”) ”2 0.2723 0.0277 2.21 0.2144 0.0356 2.84 1 0.2267 0.0733 5.85 0.1975 0.0525 4.19 2 0.1851 0.1149 9.16 0.1749 0.0751 5.99 3 0.1690 0.1310 10.44 0.1542 0.0958 7.64 5 0.1424 0.1576 12.57 0.1312 0.1188 9.47 7 0.1316 0.1684 13.42 0.1172 0.1328 10.59 10 0.1186 0.1814 14.47 0.1000 0.1500 11. 96 63 Table A-6. The Number of Photons Absorbed by Actinometer Films with Time at 0 (or 180°) Angle of Incidence amount of NB unreacted amount of NBA reacted time, hr mg/cm film mg/cm film photons (x1017) ”2 0.2876 0.0124 0. 99 0.2838 0.0162 1. 29 1 0.2880 0.0120 0. 96 0.2844 0.0156 1.24 2 0.2714 0.0286 2.28 0.2800 0.0200 1. 59 3 0.2538 0.0462 3 . 69 0.2638 0.0362 2 . 88 5 0.2492 0.0508 4 . 05 0.2592 0.0408 3.25 7 0.2409 0.0591 4.71 0.2519 0.0481 3.83 10 0.2277 0.0723 5.76 0.2428 0.0572 4 . 56 64 Table A-7. The Number of Photons Absorbed by Actinometer Films with Time at 4°C (With Exposure to 365 nm) amount of NBA reacted time, hr mg/cm film photons (x1017) 0.0140 1.12 1/2 0.0080 0.64 0.0095 0.76 0.0125 1.00 0.0238 1.90 1 0.0204 1.63 0.0184 1.47 0.0258 2.06 0.0282 2.25 2 0.0395 3.15 0.0342 2.72 0.0335 2.67 0.1026 8.19 4 0.0966 7.70 0.1244 9.91 0.1304 10.39 0.1037 8.26 6 0.1128 8.99 0.1222 9.74 0.1316 10.48 0.1032 8.22 8 0.1222 9.74 0.1446 11.52 0.1256 10.01 0.1552 12.37 10 0.1667 13.28 0.1737 13.85 0.1483 11.82 65 Table A-8. The Number of Photons Absorbed by Actinometer Films with Time at 4 C (Without Irradiation) amount of NBA reacted 17 time, hr mg/cm film photons (x10 ) 0.0010 0.08 1’2 0.0016 0.13 1 0.0028 0.22 0.0029 0.23 2 0.0028 0.22 0.0030 0.24 “ 0.0055' 0.40 0.0079 0.63 6 0.0062 0.09 0.0068 0.54 8 0.0072 0.57 0.0092 0.73 10 0.0072 0.57 0.0038 0. 30 66 Table A-9. The Numbgr of Photons Absorbed by Actinometer Films with Time at 37 C (With Exposure to 365 nm) amount of NBA reacted 17 time, hr mg/cm film photons (x10 ) 0.0164 1.31 1/2 0.0203 1.62 0.0209 1.67 0.0288 2.29 1 0.0402 3.20 0.0366 2.92 0.0776 6.18 2 0.0825 6.57 0.0994 7.92 0.1238 9.86 3 0.1307 10.41 0.1295 10.32 0.1368 10.90 5 0.1495 11.91 0.1556 12.40 0.1594 12.70 8 0.1500 11.95 0.1610 12.83 0.1611 12.84 10 0.1588 12.65 0.1637 13.04 67 Table A-10. The Numbgr of Photons Absorbed by Actinometer Films with Time at 37 C (Without Irradiation) amount of NBA reacted time, hr mg/cm film photons (5110”) 0.0016 0.13 1/2 0.0024 0.19 1 0.0020 0.16 0.0028 0.22 2 0.0020 0.16 0.0024 0.19 3 0.0032 0.25 0.0048 0.38 5 0.0046 0.37 0.0058 0.46 8 0.0043 0.34 0.0027 0.22 10 0.0058 0.46 0.0038 0.30 68 Table A-ll. The Numb r of Photons Absorbed by Actinometer Films with Time at 50 C (With Exposure to 365 nm) amount of NBA reacted time, hr mg/cm film photons (x1017) 0.0198 1.58 1/2 0.0306 2.44 0.0234 1.86 0.0538 4.29 2 0.0788 6.28 0.0675 5.38 0.0886 7.06 4 0.0992 7.90 0.0966 7.70 0.1028 8.19 6 0.1527 12.17 0.1546 12.32 0.1432 11.41 8 0.1805 14.38 0.1671 13.31 0.1449 11.54 10 0.1815 14.46 0.1695 13.50 69 Table A-12. The Numbgr of Photons Absorbed by Actinometer Films with Time at 50 C (Without Irradiation) amount of NBA reacted time, hr mg/cm film photons (x1017) 0.0018 0.14 1’2 0.0025 0.20 2 0.0014 0.11 0.0022 0.18 4 0.0033 0.26 0.0027 0.22 6 0.0026 0.21 0.0029 0.23 8 0.0028 0.22 0.0029 0.23 10 0.0028 0.22 0.0042 0.33 70 Table A-l3. The Number of Photons Absorbed by Actinometer Films for Wavelength (300 to 400 nm) amount of NBA reacted 1 6 wavelength, nm mg/cm film photons (x10 ) 3°° 8:88:88 :888 33° 8:88:88 8:88: 32° 8:88:88 :88? 33° 828888: 8:888 33° 8288888 8:888 33° 8:88:88 :88: 36° 88:88: 8:888 33° 8288888 8:88: 38° 8:888: 8:888 33° 8:88:88 :88: °°° 8:88:88 :2888 71 Table A-l4. The Number of Photons Absorbed by Actinometer Films (Control for Wavelength Effect) amount of NBA reacted film # mg/cm film photons (x1016) 1 0.00203 1.617 2 0.00432 3.442 3 0.00345 2.749 4 0.00438 3.490 5 0.00451 3.593 6 0.00287 2.287 7 0.00198 1.578 8 0.00273 2.175 9 0.00386 3.075 10 0.00497 3.960 72 Table A-15. The Number of Photons Absorbed by Actinometer Films with Water (With Exposure to 365 nm) amount of NBA reacted time, hr mg/cm film photons (1110”) 0.0443 3.53 1/2 0.0507 4.04 0.0481 3.83 0.0312 2.49 1 0.0346 2.76 0.0314 2.50 0.0493 3.93 2 0.0756 6.02 0.0653 5.20 0.0673 5.36 4 0.0584 4.65 0.0603 4.80 0.0865 6.89 6 0.0621 4.95 0.0806 6.42 0.1440 11.47 8 0.1248 9.94 0.1320 10.52 0.1488 11.86 10 0.1523 12.13 0.1288 10.26 73 Table A-16. The Number of Photons Absorbed by Actinometer Films with Water (Without Irradiation) amount of NBA reacted time, hr mg/cm film photons (x1017) 1/2 ----- --- 1 --..-.. ---.. 3 828888 8:88 4 ..---- .....- 6 ...... ....- . 88888 888 10 0. 0049 0. 39 0.0067 0.53 mollTllWHllMlllle1111111111111111115s 3 1293 03015 4883