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  1. #141
    Photo Engineer's Avatar
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    Like most books on emulsions, it speaks in generalities for the most part.

    PE

  2. #142
    holmburgers's Avatar
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    Just found this website. http://www.spectrum.kiev.ua/catalogue/?class=DY Spectrum Info - Fine Chemicals in Kiev, Ukraine.

    Spectrum Info Ltd. is a private company focused on laboratory scale synthesis of fine organic chemicals and combinatorial building blocks. We provide rare and commercially unavailable compounds for research chemists worldwide. Our office and laboratory facilities are located in the Institute of Organic Chemistry, National Academy of Sciences of Ukraine, Kiev.

    About 500 synthetic dyes of various classes covering the absorbance range 350-1100 nm are presented in the product list. Specialty dyes catalog includes laser dyes, fluorescent probes, dyes for WORM disks production and electrophotography, silver halide sensitizers for visible and near IR region, and indicators.


    Seems promising. I haven't identified any sensitizers yet, but searching "cyanine" brings up 26 hits.
    If you are the big tree, we are the small axe

  3. #143
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    Here's a good thread over at holoforum.org about sensitizing dyes... http://holoforum.org/forum/viewtopic.php?f=9&t=494

    Some of the links to various dye companies seem like good bets for obtaining these dyes.

    http://www51.honeywell.com/sm/specia...zers.html?c=23
    http://www.corchim.ru/catalog/Phot-sen_PH.html (google translated, here)
    http://www.organica.de/en/download/1...cification.pdf (it's interesting; this dye is sold at HW Sands, but as a functional laser dye, not necessarily advertised as a red sensitizer as it is at this website.)
    If you are the big tree, we are the small axe

  4. #144
    holmburgers's Avatar
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    Review of Literature for Sensitizing Dyes

    Ok, this is a work in progress, but this is the result of some armchair research I've done through, primarily, Google Books. It's a smattering of information relating to sensitizing dyes, and particularly those pre-1930ish.

    Please download the word file for links, some quotations and a better sense of the context.

    I don't claim to be making any conclusions here, but am rather just trying to get a base of information together. I recommend that people go through the links themselves and lets start discussions on certain topics. On the other hand, I don't know if we can conclude too much without some actual testing, but all this literature will certainly point us in the right direction and give us things to consider. In particular, some of the large reference lists should be very valuable for anyone wanting to go deep.

    A lot of the literature is relating to bath sensitizing, much of which is done for astrophotography. There appear to be several contradicting statements in the various sources, so be careful in jumping to conclusions. Lastly, I've undoubtedly missed sources and indeed, haven't claimed to do an exhaustive search. I would simply search "pinacyanol", "orthochrome", or other dye names in Google books and follow the links which looked promising.

    Here is a fairly complete list of all the sensitizers that are mentioned, posted mainly for the purpose of keyword searches. It'd be best to read the literature for broader context and use of the dyes . . . . .

    Earliest Survey after Vogel:
    - Ethyl Violet (triphenylmethane dye) - "red sensitizer for collodion"
    - Eosin, Erythrosin, Rose Bengal (pyronine dyes) - "green and yellow sensitizers"
    - Fast Red, Congo Red, Glycine Red, BenzoNitrol Brown (azo dyes)
    - Acridine Orange, Alizarin Blue

    Cyanine, a.k.a. quinoline blue
    - 1,1'-Di-n-amyl-4,4'-cyanine iodide

    In 1903, Miethe & Traube patented Ethyl Red (an isocyanine).
    - 1,1'-Diethyl-2,4'-cyanine iodide
    - sensitizer for green, yellow and orange
    - a.k.a. chinaldin-ethyl-cyanin

    In 1905, Homolka at Hoechst Dye Works discovered Pinacyanol.
    - 1,1'-Diethyl-2,2'-carbocyanine iodide (or bromide, or chloride)
    - Structure wasn't elucidated until mid-20's through research by Pope.

    Dicyanine and Dicyanine A were manufactured later by Hoechst.
    - 1,1'-Diethyl-2,4'-carbocyanine iodide (dicyanine)
    - 6,6'-Diethoxy-1,1'-diethyl-2,4-carbocyanine iodide (dicyanine A)

    Woolblack – a red sensitizer for gelatin
    Pinaverdol - a green sensitizer

    Orthochrom T
    Pinachrom (pinachrom violet (?))
    Homocol
    Pinaflavol

    Kryptocyanine (1919), Neocyanine (1925), Xenocyanine & other tricarbocyanines (1931) - IR sensitizers

    In summation, Pinacyanol, the most important sensitizer for the red, was used in all panchromatic materials until the thirties. Although by itself it gives fairly good sensitivity in the green in addition to its major contribution in the red, it was usually employed in conjunction with other dyes such as Orthochrome T, Pinaverdol, or pinachrome which conferred greater response in the green.”
    Attached Thumbnails Attached Thumbnails Photographic Sensitizing Chart of Progress.JPG  
    Attached Files
    If you are the big tree, we are the small axe

  5. #145
    Mustafa Umut Sarac's Avatar
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    Autochrome screen dyes are panchromatic sensitizer dyes also

    Hello Chris ,

    Are you aware of many early red, green and you call azo emulsion sensitizer dyes are used in original autochrome screen starch dyeing recipe. Its would not be a suprise to find them in autochrome panchromatic RRGGBB screen backing emulsion.

    Very important finding I think.

    Thank you for hard work , try to contact with Ukraine and obtain their price catalog. They are very Soviet times prices.

    Umut

  6. #146
    holmburgers's Avatar
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    Thanks Umut for the kind words. I didn't notice that about the autochrome screen, that's very interesting indeed.

    I agree that Ukraine prices are probably very desirable.

    Ciao!
    If you are the big tree, we are the small axe

  7. #147
    Mustafa Umut Sarac's Avatar
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    By the way , If I am not wrong there are more than 900 universities at Ukraine and they do one of the most hardcore researches in the world.

    At Kiev , one school teacher gets 100 dollars a month .

    I contacted with a Inflatable Boat seller , giant boat comes for 60 dollars including shipment. They are living hard times.

    Another story , someone advertised Hologram Business Cards at some forum , I asked the price , 50 business card costs more than 500 dollars due to preparing the films.

    I contacted with Kiev university Enterprize and 1000 hologram business card costs 100 dollars.

    What else ?

    Umut

  8. #148
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    How relevant are sensitizing dyes used for solar cells? A lot of research is going on. For example:

    Here we report on the sensitization of semi-
    conductor particles (TiO2 ) by organic dyes such
    as xanthenes (rhodamine 101, fluorescein and 5(6)-
    carboxyfluorescein) and azo dyes (alizarin yellow R,
    alizarin yellow 2G and carboxyarsenazo). Photostabil-
    ity of these dyes will be determined for possible use
    as sensitizers for the nanocrystalline solar cell. The
    role played by redox couple (e.g. I3 − /I− ) electrolyte
    in regenerating the neutral sensitizer dye molecules,
    and thus, stabilization of the dye molecule will be also
    studied. The chosen dyes possessing carboxylate or
    hydroxyl function groups that enable direct interaction
    with the surface of TiO2 particles, thereby providing
    a path for electron transfer from the excited dye
    adsorbate to the semiconductor.....
    From "The interaction and photostability of some xanthenes and selected azo sensitizing dyes with TiO2 nanoparticles", D. EL Mekkawi and M. S. A. Abdel-Mottaleb

    Also, US Patents 4173478 and 4476220 discuss azo dyes as silver halide photographic sensitizers. They do discuss heat processed materials, though.
    Last edited by kb3lms; 07-24-2012 at 08:40 AM. Click to view previous post history. Reason: Added informtation
    All this has happened before, and all this will happen again.

  9. #149
    Mustafa Umut Sarac's Avatar
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    kb3lms ,

    I opened a thread last year on tio2 use , it has ultrawide spectrum and even with coating with dyes increases the end power of solar cell. I dont think a printed on film solar cell maker wants to invent and use a expensive dye , so the widest available dye would be the selection with some drawbacks.

    My intention is to use titanium dioxide in the place of silver. If I remember correctly , a reducing agent was needed and final decision was it would cost more than buying silver. Its silly but without forum support , I dont lots of options.

    You can dig it now and if you can.

    By the way , I saw rhodamine , it doesnt work if you dont freeze it. Alizarin dyes are cheap and widely available and I am right , they want to make the lowest cost device.

    Umut

  10. #150
    Mustafa Umut Sarac's Avatar
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