Química 2

Fotografia
4 ECTS; 1º Ano, 2º Semestre, 30,0 TP + 5,0 OT

Lecturer
- Manuel Alberto Nogueira Henriques Rosa

Prerequisites
Not applicable.

Objectives
Development of capacities for the comprehension of general chemistry and its application in the graphic processes, Comprehension of the chemical variables within the process.

Program
Theoretical component:
1 - Ionic balance: 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.
2 - 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
3 - 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 component:
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: Superaditivity, pH, temperature, development time and concentration of the developing solution.

Evaluation Methodology
Continuous Assessment has practical and theoretical components. A minimum mark of 10 is required for both components. The final mark is the weighted average of the two components: practical (60%) and theoretical (40%)

Bibliography
- Stroebel, L. e Compton, J. e Current, I. e Zakia, R. (2000). Basic Photographic Materials and Processes. Boston: Focal Press
- Atkins, P. (1989). General Chemistry. Nova Iorque: Scientific American
- Hirsch, R. (1991). Photographic Possibilities – The expressive use of ideas, materials and processes. Boston: Focal Press
- Chang, R. e Goldsby, K. (2013). Química. New York: McGraw Hill

Method of interaction
Lectures and laboratory classes in which the students will learn how to manage the chemical processes variables.

Software used in class
Not Applicable.