Science and Technology for the Conservation of Cultural Heritage

THEORY: 1) Resonance in Organic Chemistry – 2 hours 2) Reactivity in Organic Chemistry – 6 hours: a. Fundamentals of reactivity; definitions of electrophile and nucleophile; reactions of alkenes, alkynes, and dienes; nucleophilic substitution and elimination reactions; benzene reactions; reactions of substituted benzenes and resonance/inductive effects; formation of diazonium salts; reactions of benzoquinones; reactions of Class I and Class II carbonyl compounds 3) Drying Oils – 6 hours: History of drying oils; origin and production; composition of drying oils; drying processes and mechanisms; catalysis and driers; thermal polymerization and stand oil; aging of drying oils and degradation processes; characteristics of modern drying oils 4) Tempera Binders – 6 hours: Amino acids, peptide bond, proteins and their structures; drying process of protein-based binders; animal glues: chemical composition, structure, production, and properties; egg white, egg yolk, and casein: characteristics; protein aging; polysaccharides: aging and degradation 5) Synthetic Binders – 4 hours: Definition of polymers; polyaddition and polycondensation mechanisms; acrylic binders: solutions, emulsions, and related chemical characteristics; fundamentals of emulsion polymerization; drying of emulsion binders and surfactant migration; photochemical aging and degradation; polyvinyl acetate and alkyd binders 6) Principles of Colour Chemistry – 4 hours: History of natural and synthetic dyes; causes of colour and electronic excitation; valence bond approach to colour theory; application of the valence bond theory to azo and anthraquinone dyes 7) Natural Organic Dyes, Pigments, and Lakes – 6 hours: Definitions; characteristics of textile fibers; dyeing theories (absorption, solubility, chemical, electro-colloidal) and techniques (hot, mordant, direct dyeing); definition of lakes; characteristics of natural organic pigments (amber, bitumen, sepia, mummy brown); main classes of natural dyes and their characteristics and applications (anthraquinones, naphthoquinones, benzoquinones and xanthones, quinonoids, flavonoids, flavones, flavonols, catechins, tannins, other flavonoid dyes, dyes from lichens, polyenic dyes, indigoids, alkaloids) 8) Synthetic Organic Pigments and Dyes – 6 hours: The first synthetic dyes (picric acid, mauveine, magenta); azo dyes: history, synthesis, examples, equilibria and effects of chemical structures, synthetic classification and classes; characteristics and classes of carbonyl dyes (anthraquinones, indigoids, benzodifuranones); polycyclic pigments (anthraquinones, perylenes, perinones, diketopyrrolopyrroles, quinacridones, isoindolinones, dioxazines, phthalocyanines); polyenic and polymethinic dyes; sulfur and nitro dyes; dye stability with examples LABORATORY: 1) Raman analysis of organic pigments and dyes – 2 hours 2) Innovative spectroscopic and spectrometric techniques for diagnostic purposes – 2 hours 3) Extraction of dyes and preparation of pigment lakes – 4 hours 4) Development of a diagnostic protocol for organic materials – 2 hours 5) Spectral data processing for the analysis of organic materials – 2 hours

It is highly useful to know the fundamentals about the main classes of organic molecules (functional groups) and natural compounds (carbohydrates, aminoacids, lipids).

“Chimica Organica” , J. McMurry, Edition IX, Brooks/Cole Pub Co, 2011; “Organic Chemistry” , P. Y. Bruice, Edition VIII., Global Edition, 2016; “Natural Dyes”, D. Cardon, Archetype Books, 2007 “Colour Chemistry”, R. M. Christie, Edition II, Royal Society of Chemistry, 2014 “Color Chemistry”, H. Zollinger, Edition III, Wiley-VCH, 2001

Highly recommended.

The assessment consists of an oral exam, which accounts for 83% of the total credits (5 out of 6 credits), and refers to the theoretical content delivered through lectures, and a practical exam, accounting for 17% of the total credits (1 out of 6 credits), which refers to the practical content covered during exercises and laboratory sessions. As for the oral exam, it consists of a series of questions focused on the topics covered during the lectures, aimed at verifying the achievement of objectives 1, 3, 5, 6, and 7. The questions are in English, open-ended, and generally cover broad topics. Students must answer in English and are expected to demonstrate extensive knowledge of the subject. Clarifications and further questions may be asked by the instructor to ensure a clearer and more thorough assessment of the learning objectives. As for the practical exam, it consists of the evaluation of the student’s active participation during the laboratory exercises (25%) and a report (75%) related to one of the exercises conducted during the lab sessions, selected by the instructor from those covered in class. The choice will be communicated during the course sessions, so students are required to attend these exercises; attendance at the lab exercises is therefore mandatory. If a student is unable to attend, they must contact the instructor in advance so that a possible make-up can be arranged. The report must be submitted to the instructor via email at least 7 days before the exam date, to allow sufficient time for evaluation. The practical exam aims to assess the achievement of objectives 2, 4, and 8.

The theoretical lessons (5 credits), mainly related to research results 1, 3, 5, 6, and 7, are delivered as frontal lectures in the classroom supported by presentations. The initial lessons include a section of exercises carried out together, in which students can usually be involved, aimed at reinforcing some concepts addressed at a theoretical level. Furthermore, for the final topics (organic dyes and pigments), students will be asked to give a lecture to their peers, divided into groups and using materials provided by the lecturer. For the laboratory component (1 credit), linked to research results 2, 4, and 8, practical sessions are planned that cover various techniques and methodologies (extraction, spectroscopic techniques, data processing), which are aimed at conveying practical aspects of diagnostics for organic materials. Student participation is encouraged through the interpretation of provided data (individual student work aimed at writing the laboratory report) and the design of a diagnostic process for a case study selected by the professor (group work). Furthermore, the professor is available - compatibly with the time dedicated to theoretical lessons - to hold brief in-depth lessons on specific topics suggested by the students.

THEORY: 1) Resonance in Organic Chemistry – 2 hours 2) Reactivity in Organic Chemistry – 6 hours: a. Fundamentals of reactivity; definitions of electrophile and nucleophile; reactions of alkenes, alkynes, and dienes; nucleophilic substitution and elimination reactions; benzene reactions; reactions of substituted benzenes and resonance/inductive effects; formation of diazonium salts; reactions of benzoquinones; reactions of Class I and Class II carbonyl compounds 3) Drying Oils – 6 hours: History of drying oils; origin and production; composition of drying oils; drying processes and mechanisms; catalysis and driers; thermal polymerization and stand oil; aging of drying oils and degradation processes; characteristics of modern drying oils 4) Tempera Binders – 6 hours: Amino acids, peptide bond, proteins and their structures; drying process of protein-based binders; animal glues: chemical composition, structure, production, and properties; egg white, egg yolk, and casein: characteristics; protein aging; polysaccharides: aging and degradation 5) Synthetic Binders – 4 hours: Definition of polymers; polyaddition and polycondensation mechanisms; acrylic binders: solutions, emulsions, and related chemical characteristics; fundamentals of emulsion polymerization; drying of emulsion binders and surfactant migration; photochemical aging and degradation; polyvinyl acetate and alkyd binders 6) Principles of Colour Chemistry – 4 hours: History of natural and synthetic dyes; causes of colour and electronic excitation; valence bond approach to colour theory; application of the valence bond theory to azo and anthraquinone dyes 7) Natural Organic Dyes, Pigments, and Lakes – 6 hours: Definitions; characteristics of textile fibers; dyeing theories (absorption, solubility, chemical, electro-colloidal) and techniques (hot, mordant, direct dyeing); definition of lakes; characteristics of natural organic pigments (amber, bitumen, sepia, mummy brown); main classes of natural dyes and their characteristics and applications (anthraquinones, naphthoquinones, benzoquinones and xanthones, quinonoids, flavonoids, flavones, flavonols, catechins, tannins, other flavonoid dyes, dyes from lichens, polyenic dyes, indigoids, alkaloids) 8) Synthetic Organic Pigments and Dyes – 6 hours: The first synthetic dyes (picric acid, mauveine, magenta); azo dyes: history, synthesis, examples, equilibria and effects of chemical structures, synthetic classification and classes; characteristics and classes of carbonyl dyes (anthraquinones, indigoids, benzodifuranones); polycyclic pigments (anthraquinones, perylenes, perinones, diketopyrrolopyrroles, quinacridones, isoindolinones, dioxazines, phthalocyanines); polyenic and polymethinic dyes; sulfur and nitro dyes; dye stability with examples LABORATORY: 1) Raman analysis of organic pigments and dyes – 2 hours 2) Innovative spectroscopic and spectrometric techniques for diagnostic purposes – 2 hours 3) Extraction of dyes and preparation of pigment lakes – 4 hours 4) Development of a diagnostic protocol for organic materials – 2 hours 5) Spectral data processing for the analysis of organic materials – 2 hours

It is highly useful to know the fundamentals about the main classes of organic molecules (functional groups) and natural compounds (carbohydrates, aminoacids, lipids).

“Chimica Organica” , J. McMurry, Edition IX, Brooks/Cole Pub Co, 2011; “Organic Chemistry” , P. Y. Bruice, Edition VIII., Global Edition, 2016; “Natural Dyes”, D. Cardon, Archetype Books, 2007 “Colour Chemistry”, R. M. Christie, Edition II, Royal Society of Chemistry, 2014 “Color Chemistry”, H. Zollinger, Edition III, Wiley-VCH, 2001

Highly recommended.

The assessment consists of an oral exam, which accounts for 83% of the total credits (5 out of 6 credits), and refers to the theoretical content delivered through lectures, and a practical exam, accounting for 17% of the total credits (1 out of 6 credits), which refers to the practical content covered during exercises and laboratory sessions. As for the oral exam, it consists of a series of questions focused on the topics covered during the lectures, aimed at verifying the achievement of objectives 1, 3, 5, 6, and 7. The questions are in English, open-ended, and generally cover broad topics. Students must answer in English and are expected to demonstrate extensive knowledge of the subject. Clarifications and further questions may be asked by the instructor to ensure a clearer and more thorough assessment of the learning objectives. As for the practical exam, it consists of the evaluation of the student’s active participation during the laboratory exercises (25%) and a report (75%) related to one of the exercises conducted during the lab sessions, selected by the instructor from those covered in class. The choice will be communicated during the course sessions, so students are required to attend these exercises; attendance at the lab exercises is therefore mandatory. If a student is unable to attend, they must contact the instructor in advance so that a possible make-up can be arranged. The report must be submitted to the instructor via email at least 7 days before the exam date, to allow sufficient time for evaluation. The practical exam aims to assess the achievement of objectives 2, 4, and 8.

The theoretical lessons (5 credits), mainly related to research results 1, 3, 5, 6, and 7, are delivered as frontal lectures in the classroom supported by presentations. The initial lessons include a section of exercises carried out together, in which students can usually be involved, aimed at reinforcing some concepts addressed at a theoretical level. Furthermore, for the final topics (organic dyes and pigments), students will be asked to give a lecture to their peers, divided into groups and using materials provided by the lecturer. For the laboratory component (1 credit), linked to research results 2, 4, and 8, practical sessions are planned that cover various techniques and methodologies (extraction, spectroscopic techniques, data processing), which are aimed at conveying practical aspects of diagnostics for organic materials. Student participation is encouraged through the interpretation of provided data (individual student work aimed at writing the laboratory report) and the design of a diagnostic process for a case study selected by the professor (group work). Furthermore, the professor is available - compatibly with the time dedicated to theoretical lessons - to hold brief in-depth lessons on specific topics suggested by the students.