Textilkemi II, Gränsytor och kemisk behandling / Textile
Chemistry II, Interfaces and Chemical Treatment 15 ECTS
Examination for Chemical Treatment Part of the
Textile chemistry II, 5.0 ECTS
Ladokcode: AT2GK1
The exam is given to: Master students in Textile Engineering program Date of exam: 2018-05-28 Time: Location: 09:00 – 13:00 D303 Means of assistance: Miniräknare/Calculator Ordbok/Dictionary
Total amount of point on exam: 45p Requirements for grading:
F: 0 - 20 points, Fx: 21 – 26 points, E: 27 – 28 points, D: 29 – 31 points, C: 32 – 35 points, B: 36 – 39 points, A: 40 – 45 points.
The result from Chemical treatment exam is combined with the results of the Surface chemistry exam to give the final grade.
Additional information:
You can give your answers to questions on exam sheet or separate paper if you need more space.
Your corrected examinations will be available from the student centre within 3 weeks after the examination date.
How to calculate Final examination score on Textile chemistry II:
Total amount of the points on exam of Textile chemistry II is 85 (=surface chemistry 40p+chemical treatment 45p)
F: 0 - 40 points, Fx: 41 – 46 points, E: 47 – 52 points, D: 53 – 59 points, C: 60 – 67 points, B: 68 – 75 points, A: 76 – 85 points.
The results are posted no longer than three weeks after the exam Important! Do not forget to write your name on each paper you hand in. Good Luck!
Contact person during examination: Phone number:
1. a. In the dyeing experiment, 5 g of dye stuff was added into 100 g of water and acetic acid mixture. The water, acetic acid was mixed 50%/50% by weight. a). what is weight concentration of dye stuff in the total solution? (1p)
b. In the NaOH pretreatment of polyester, 350 ml 2 M NaOH solution needs to be prepared. b). How much NaOH is needed in this case (please calculate the weight in g)? (1p)
c. However, a mistake was made during the preparation, 40 g of NaOH was added and 400 ml total volume was prepared. c). could you please calculate what is the molar concentration of NaOH solution in this case? (1p)
You need to show the calculation steps rather than present the final answer (Hint: the atomic mass of element is attached at the end of this exam)
2. a. There are two types of mechanisms for antimicrobials. Name these two mechanisms. (1p) What are the pros and cons with each mechanism? (1p) b. We have discussed an antimicrobial agent that can be derived from crustacean shells. This antimicrobial is both biodegradable and non-toxic. Name this compound. (1p)
c. Can you identify the chemical structure of that compound we are discussing from below? (extra 1p) Please circle the correct structure as your answer.
3. a. For the dyeing of textile, for example dyeing of polyester, in connection with Tg
theory, is it more efficient to dye polyester below Tg or above Tg temperatue of
polyester? Please motivate your answer as well. (1p)
b. could you please name two advantages to use high temperature method for dyeing of polyester than carrier method? (1p)
4. a. Concerning UV protection application, which fiber has better solar protection factor (SPF), cotton or polyester? (1p)
(c)
b. What can UVA and UVB radiation do to human? Please answer the effect of UVA and UVB separately. (1p)
5. a. Nanomaterials and nanotechnology is considered as a future technology, actually a lot of them are already happening. We now have: a) A graphene sheet with size of 10×10 cm and 10 layers of C atoms. b) Silver colloidal with particle size of 200 nm (assuming spherical in shape) c) A pattern with pitch size of 90 nm and 100 nm spacing. d) A pattern with pitch size of 150 nm and spacing of 50 nm (the height of pitch in (c) and (d) are both 400 nm, as shown in scratch below). e) A rod with length of 10 µm and diameter of 50 nm. f) A dot such as fullerene with diameter of 1 nm. Please answer which (from a to f, could be multiple choices) of those fit the definition of nanomaterial/nanostructure? You can motivate your answer if you are not sure. (3p) Hint: thickness of single layer C atom is 3.35 Å.
Two to three correct answers gives 1p, four to five correct answers gives 2p, six correct answers gives 3p.
(c)
(d)
b. We learned that nanoparticles such as silver dispersed in solution might exhibit surface plasmon resonance phenomenon which causes absorption of light that is different than the bulk silver. We observed that during the synthesis of silver
nanoparticle, the color of solution can vary from light yellow, dark yellow, light grey to dark grey depending on synthesis parameters. What happened that caused the change of color of silver nanoparticle in solution? (1p)
c. One advantage of nanomaterial is the significant larger surface area/bulk ratio. Let's calculate that. Assuming we have perfectly dispersed nano-, micro- and bulk particles, with particle size (assuming spherical shape) of i) 10 nm, ii) 10 µm and iii) 10 mm. What is the corresponding surface area of 1 kg of each (i, ii, and iii) material?
Assuming the material is silver with density of 10.5 g cm-3. Hint: using SI units in all the calculations. (3p)
6. There are many active researches about using TiO2 nanoparticles for
anti-bacterial/self-cleaning application of textile.
a. Why is TiO2 chosen? (What is special about TiO2?) (1p)
150 nm 50 nm 400 nm 90 nm 100 nm 400 nm
b. How does TiO2 function in the application that requires anti-bacterial/self-cleaning?
(Under what condition will TiO2 function?) (1p)
c. What are the key advantages of applying digital ink-jet printing in textile sector (please name at least three that is related to Swedish textile industry)? (2p)
7. We learned that fluorocarbons have significant environmental problems. a. What are the main application (or functionality) of applying fluorocarbon component in textile industry? (1p)
b. What is the problem of fluorocarbon compounds in the nature (Why are some of fluorocarbon compounds listed on the persistent organic pollutants under the Stockholm Convention?) (1p)
c. In order to achieve super-hydrophobicity, we learned a lot from nature, such as lotus leaves. What can we learn from the lotus leaves (lotus effect)? (1p)
d. What should we do (what is the setup?) in order to mimic the lotus effect on a textile in order to achieve super-hydrophobicity (avoid using fluorocarbon in the setup)? (2p)
8. Question concerning Enzyme:
a. Explain why enzymes are denaturated at extreme pH values. (1p)
b. Give a description and characteristics of the primary, secondary and tertiary structure of proteins. Explain the interactions that stabilize the different structures. (1p)
c. How would you determine Vm and Km for Michaelis-Menten kinetics? Make use
of an illustration in your explanation. (2p)
d. In dew retting flax stems are degraded by the synergistic action of at least 4 different enzymes. Please, give the systematic names of the 4 different enzymes and describe their mode of action. (1p)
9. On the basis of your knowledge on enzymes, fibres and textile processing describe how you would perform a bioscouring process (cotton fabrics) using enzymes. Motivate the choice of the enzyme; describe the process, process conditions and equipment. (3p)
10. Give two (2) examples (both the abbreviation and full name of technique) of
microscopic techniques used for the characterization of fiber surfaces and describe one of them (your choice) briefly. (2p)
11. An antistatic finish can decrease the charge buildup. The antistatic agents work by two main mechanisms, which are they? (2p)
12. Three elements are needs to ignite a fire, which is heat, fuel, and an oxidizing agent (usually oxygen). A fire naturally occurs when the elements are present and combined in the right mixture, meaning that fire is actually an event rather than a thing.
In the flame retardant finishing application, it is possible to apply materials to textile which could have reaction as below:
Could you please explain what is the strategy for flame retardant finishing in this case according to the ‘combustion cycle for fibers’ below? (2p)
Schematic plot of combustion cycle for fibers
13. Combine the following structures (a – e) with the correct application (1 – 5): (5p) 1 Antimicrobial agent
2 Softener (cationic) 3 Flame-retardant agent 4 UV protection
a)
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