Publication in the Diário da República: Despacho n.º 2435/2023 de 17/02/2023
6 ECTS; 1º Ano, 1º Semestre, 30,0 PL + 30,0 TP + 10,0 OT , Cód. 964561.
Students should understand general chemistry topics and its application to photographic processes as well as the chemical reactions associated with developent processes.
1-Structure of matter: properties of matter; extensive and intensive properties; density and temperature (scales). Classification of matter: mixtures and pure substances. The atoms. The discovery of subatomic particles. Atomic number and isotopes. Ions. Periodic table. Periodic variation of metals, non-metals and metaloids. Electronic configurations and the periodic table: variation of atomic properties.
2-Chemical bonding: Octet rule. Covalent bonds, ionic and metal. Nomenclature of ionic compounds.
3-Stoichiometry: atomic mass, mole, molar mass and chemical reactions. Hit chemical equations; solutions and molarity. Preparation of solutions for weighing, diluting and from concentrated solutions.
4-Acids and bases: acid-base systems Bronsted-Lowry and Ahrrenius. The auto-ionization of water. The concept of pH. PH measurement: indicators and meters. PH electrode sensor. The reference electrode. Operation of the combined electrode. Temperature effect on the pH measurement. Calibration of the pH meter.
5-Oxidation-reduction: Oxidation-reduction reactions; Redox reaction adjustment; Electrochemical cells; Standard reduction potentials.
6-Organic Chemistry: Alkanes and Cycloalkanes. Nomenclature of saturated hydrocarbons. Nomenclature of cycloalkanes. Functional groups: Alcohols and ethers; Aldehydes and ketones; Carboxylic acids; Esters; The amines; Amides; polymers.
7-Chemistry of black and white photography: BW film Constitution. photochemical mechanisms of image formation; Formation of the latent image; Variation of the photosensitivity of silver salts with the wavelength of the radiation; Mechanism of spectral sensitization; Orthocromia, pancromia and infrared sensitization ; most common sensitizers. Revelation; Chemical agents of revelation (reducers); Acid-base balance of Hydroquinone; redox balance of hydroquinone; metol; the development mechanism; The shape of the grain metallic silver after development; physical development and chemical development; The superaditivity; alkali agents; antioxidants; Restrainers; Other agents; The particular case of sodium sulfite; Examples of the developing solutions. Stop bath. Fixation; Fixation mechanism; Composition of the fixing bath. Turning. Washing.
Practical work 1- ab work for the ambiance of students to chemistry laboratory, knowledge of commonly used material, the use of analytical balances.
Practical work 2-laboratory work for the implementation of the stoichiometry of knowledge in the preparation of solutions for weighing, dilution and from concentrated solutions.
Pratical work 3-Practical work of production and optimization of the operating conditions of a solution of developing agent. The optimization is performed by studying the following process variables on the development of a paper positive:pH, development time and concentration of the developing solution.
To pass the course students have to complete all assignments and respective reports (P, corresponding to 40%) and two written tests on theoretical content (T, correspondig to 60%).
1 written test
- Current, I. e Compton, J. e Stroebel, L. e Zakia, R. (2000). Basic Photographic Materials and Processes.. Boston: Focal Press
- Atkins, P. (1989). General Chemistry. New York: Scientific American
- Chang, R. e Goldsby, K. (2019). Química. New York: McGraw Hill
Lectures, theoretical-practical classes and laboratory work involving experimentation with development processes.
Software used in class