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Article
Publication date: 23 May 2008

A.A. Bahajaj and A.M. Asiri

The purpose of this paper is to evaluate the photochromic performance of photochromic compounds in polymer matrices.

514

Abstract

Purpose

The purpose of this paper is to evaluate the photochromic performance of photochromic compounds in polymer matrices.

Design/methodology/approach

The polystyrene films doped with photochromic fulgide were prepared and the effect of UV irradiation were studied using spectrophotometer. The reversible reaction was effected using white light. The effect of heat was also determined.

Findings

A film of the green coloured fulgide 2‐E doped in polystyrene polymer was irradiated with UV light (366 nm), the film turned blue. The latter colour was partially switched back to the original green colour when the film was irradiated with a white light. Increasing the annealing temperatures, increases the percentage conversion of 2‐C to 2‐E. The observed large bathochromic shifts in λmax of 2‐C and the partial conversion of 2‐C to 2‐E were rationalised on the bases of electronic and steric effects. It was found that both isomers 2‐C and 2‐E absorbed white light and they interconvert. The kinetics of photocoloration and photobleaching processes were followed spectrophotometrically by monitoring the absorbance of the ring closed product 2‐C at its λmax of 620 nm. The apparent first‐order rate constants for both processes were determined. It was found that there was slight variation in the rate constant for photocoloration reaction with annealing temperature. On the other hand, the apparent first‐order rate constant of the photobleaching reaction decreases with increasing the annealing temperature.

Research limitations/implications

The polystyrene polymer doped photochromic fulgides described in the present paper was prepared and studied. The principle of study established can be applied to any type of polymer or to any type of photochromic compounds.

Practical implications

The photochromic materials developed can be used for different applications, such as coatings and holography.

Originality/value

The method developed may be used to enhance the performance of photochromic materials.

Details

Pigment & Resin Technology, vol. 37 no. 3
Type: Research Article
ISSN: 0369-9420

Keywords

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Article
Publication date: 23 March 2010

A.A. Bahajaj, A.M. Asiri, A.M. Alsoliemy and A.G. Al‐Sehemi

The purpose of this paper is to evaluate the photochromic performance of photochromic compounds in polymer matrices.

497

Abstract

Purpose

The purpose of this paper is to evaluate the photochromic performance of photochromic compounds in polymer matrices.

Design/methodology/approach

The poly(methyl methacrylate) (PMMA) and epoxy resin doped with photochromic spirobenzopyran were prepared and the effects of ultraviolet (UV) irradiation were studied using spectrophotometer. The reversible reaction was effected using white light. Photochemical fatigue resistance of these films was also studied.

Findings

Irradiation of colourless 1′,3′,3′‐trimethyl‐6‐nitrospiro[2H‐1‐benzopyran‐2,2′‐indoline] spiropyran (SP) doped in PMMA and epoxy resin with UV light (366 nm) results in the formation of an intense purple‐red coloured zwitterionic photomerocyanine (PMC). The reverse reaction was photochemically induced by irradiation with white light. Photocolouration of SP doped in PMMA follows a first‐order rate equation (k=0.0011 s−1), while that doped in epoxy resin deviates from linearity. It was found that photobleaching follows a first‐order equation in both matrices. The photobleaching rate constant of PMC in both matrices is the same and equals 0.0043 s−1. Spirobenzopyran doped in PMMA shows better fatigue resistance than that doped in epoxy resin.

Research limitations/implications

The PMMA and epoxy resin polymers doped with photochromic spirobenzopyran described in the present paper were prepared and studied. The principle of study established can be applied to any type of polymer or to any type of photochromic compounds.

Practical implications

The photochromic materials developed can be used for different applications, such as coatings and holography.

Originality/value

The method developed may be used to enhance the performance of photochromic materials.

Details

Pigment & Resin Technology, vol. 39 no. 2
Type: Research Article
ISSN: 0369-9420

Keywords

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Article
Publication date: 17 May 2013

Abdullah M. Asiri, Khalid A. Alamry and Mahmoud A. Hussein

The purpose of this paper is to investigate the effect of annealing on photochromic performance of (E)‐dicyclopropylmethylene‐(2, 5‐dimethyl‐3‐furylethylid‐ene)‐succinicanhydride…

143

Abstract

Purpose

The purpose of this paper is to investigate the effect of annealing on photochromic performance of (E)‐dicyclopropylmethylene‐(2, 5‐dimethyl‐3‐furylethylid‐ene)‐succinicanhydride doped in polyacrylic acid thin film.

Design/methodology/approach

(E)‐dicyclopropylmethylene‐(2,5‐dimethyl‐3‐furyl‐ethylidene)‐succinic‐anhydride (DMDFS‐E) fulgide doped in polyacrylic acid thin films was prepared. DMDFS‐E fulgide doped in polyacrylic acid thin films was heated at various annealing temperatures. Photocoloration, photobleaching and photochemical fatigue resistance for the desired DMDFS‐E fulgide doped in polyacrylic acid thin films were studied.

Findings

Upon irradiation with UV light (366 nm), fulgide DMDFS‐E undergoes a conrotatory ring closure to the pinkish colored closed form C (523 nm). The later color was switched back to the original color when the films were irradiated with white light. The kinetics of photocoloration and photobleaching processes were followed spectrophotometrically by monitoring the absorbance of the ring closed product DMDFS‐C at its λmax of 523 nm. The first‐order plots of photocoloration reaction showed distinct linear line at different temperatures. The slope of these first‐order lines corresponding to the rate constants k. It was found that for photocoloration reaction, the rate constant of the photocoloration reaction was slower than the photobleaching reaction and both reactions decrease with increasing the annealing temperatures. It was found that there was almost improvement of photochemical fatigue resistance of fulgide DMDFS‐E doped in polyacrylic acid thin film at several of the annealing temperatures.

Originality/value

The results obtained in this work showed that the photochromic properties of DMDFS fulgide E were improved upon annealing the film at 100°C. Therefore, it would be recommended for improvement to apply fulgides as annealed polymer films.

Details

Pigment & Resin Technology, vol. 42 no. 3
Type: Research Article
ISSN: 0369-9420

Keywords

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300

Abstract

Purpose

To evaluate the photochromic performance of fulgide 1E with ferrocene in polymer matrices.

Design/methodology/approach

The fulgide 1E with ferrocene dye 2 doped in polymethylmethacrylate was prepared and the effects of UV irradiation were studied using spectrophotometer. The reversible reaction was effected using white light. The effect of heat was also determined.

Findings

A film of the brown coloured fulgide 1E with ferrocene doped in PMMA polymer was irradiated with ultraviolet light (365 nm), the film turned red. The later colour was partially switched back to the original brown colour when the film was irradiated with a white light. It was found that the rate constants of photocoloration reaction at initial stages are faster than those at late stages. Similarly, the photocoloration reaction was slower than the photobleaching reaction. Photocoloration reaction decreased with the increase of the annealing temperatures, but for photobleaching reaction, the rates were almost similar (at 46 and 82°C). The fatigue resistance of the film was greatly improved when the annealing temperature increased to 82°C.

Research limitations/implications

The polymethylmethacrylate polymer doped photochromic fulgide 1E and ferrocene 2 described in the present paper was prepared and studied. The principle of study established can be applied to any type of polymer or to any type of photochromic compounds.

Practical implications

The photochromic materials developed can be used for different applications, such as coatings and holography.

Originality/value

The method developed may be used to enhance the performance of photochromic materials.

Details

Pigment & Resin Technology, vol. 37 no. 3
Type: Research Article
ISSN: 0369-9420

Keywords

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Article
Publication date: 6 November 2009

A.A. Bahajaj, A.M. Asiri, A.M. Alsoliemy and A.G. Al‐Sehemi

The purpose of this paper is to evaluate the photochromic performance of photochromic compounds in polymer matrices.

460

Abstract

Purpose

The purpose of this paper is to evaluate the photochromic performance of photochromic compounds in polymer matrices.

Design/methodology/approach

The poly(methyl methacrylate) PMMA and epoxy resin doped with photochromic spirooxazine (SO) are prepared and the effects of ultraviolet (UV) irradiation are studied using spectrophotometer. The reversible reaction is effected using white light. Photochemical fatigue resistance of these films is also studied.

Findings

Irradiation of colourless 7′,8′‐dichloro‐1,3,3‐trimethylspiro[indoline‐2,3′‐[3H]benzo[b][1,4]oxazine] (SO) doped in PMMA and epoxy resin with UV light (366 nm) results in the formation of an intense purple‐red coloured zwitterionic photomerocyanine (PMC). The reverse reaction is photochemically induced by irradiation with white light. Photocolouration and photobleaching reactions follow a first‐order rate equation. It is found that photocoloration rate constant of (SO) in both matrices is almost the same, which is unexpected. On the other hand, the rate of photobleaching reaction of (PMC) in PMMA is twice slower than that in the epoxy resin. It seems that the presence of the two chlorine atoms at positions 7′ and 8′ of the benzooxazine moiety destabilise the PMC in epoxy resin film and results in speeding up the fading process compared to that in PMMA. SO doped in epoxy resin shows much better fatigue resistance than that doped in PMMA.

Research limitations/implications

The PMMA and epoxy resin polymers doped photochromic spirobenzooxazine described in this paper were prepared and studied. The principle of study established can be applied to any type of polymer or to any type of photochromic compounds.

Practical implications

The photochromic materials developed can be used for different applications, such as coatings and holography.

Originality/value

The method developed may be used to enhance the performance of photochromic materials.

Details

Pigment & Resin Technology, vol. 38 no. 6
Type: Research Article
ISSN: 0369-9420

Keywords

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Article
Publication date: 1 October 2005

A.A. Bahajaj and Abdullah M. Asiri

To evaluate the photochromic performance of photochromic compounds in polymer matrices.

374

Abstract

Purpose

To evaluate the photochromic performance of photochromic compounds in polymer matrices.

Design/methodology/approach

The epoxy resin doped with photochromic fulgide were prepared and the effect of UV irradiation were studied using spectrophotometer. The reversible reaction was effected using white light. The effect of heat was also determined.

Findings

A film of fulgide 1‐E doped in epoxy polymer was irradiated with UV light (366 nm), the film turned pink. The later colour was switched back to the original colour when the film was irradiated with a white light. The photocoloration and photobleaching obeyed first order rate equations with rate constants being 4.19×10−3 s−1 and 2.86×10−2 s−1, respectively. It was found that the film showed a good fatigue resistance. Another film was preheated at 80°C for 1‐4 h. No change in the UV absorption spectra of the film was observed. Similarly, the photocoloration and photobleaching of the annealed film showed first order rate equations with rate constants being 8.77×10−3 s−1 and 4.02×10−2s−1, respectively. Interestingly, the photocoloration and photobleaching reactions of the annealed film were faster than those of the non‐annealed film.

Research limitations/implications

The epoxy resin doped photochromic fulgides described in the present paper was prepared and studied. The principle of study established can be applied to any type of resin or to any type of photochromic compounds.

Practical implications

The photochromic materials developed can be used for different applications, such as coatings and holography.

Originality/value

The method developed may be used to enhance the performance of photochromic materials.

Details

Pigment & Resin Technology, vol. 34 no. 5
Type: Research Article
ISSN: 0369-9420

Keywords

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