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Gan Eng Seng School Team 1

Gan Eng Seng School Team 1. Republic Polytechnic Scientific Thinking Programme 2008. The comparison of different brands of hairdye and their effects of human hair. Aim and Hypothesis.

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Gan Eng Seng School Team 1

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  1. Gan Eng Seng School Team 1 Republic Polytechnic Scientific Thinking Programme 2008 The comparison of different brands of hairdye and their effects of human hair.

  2. Aim and Hypothesis Aim: To determine which brand of hair dye will least affect the tensile strength of the human hair and number of hair breaks found on the human hair. Hypothesis: The more expensive the hair dye, the better the quality of the ingredients, and hence, the least it will affect the tensile strength and the number of breaks on the human hair

  3. About our Hair Human hair is made of keratin, water and dead cells Each strand of hair is made up of three layers; the Medulla, Cuticle Cortex. Cuticle is made up of scale-like, overlapping protein cells which protect the cortex A healthy hair is when the cuticle lie flat around the hair shaft. A damaged hair is when the cuticle of the hair is raised. http://www.hoyu-usa.com/bigen/abouthair.php

  4. Ingredients of a Permanent Hair Dye Will usually contain: • Oxidizing Agent • Will usually be Hydrogen Peroxide. • It enters the cortex and removes some of the melanin from the cortex layer. • Lightens the colour of hair, and also introduces dye molecules. • Strong Alkali • Usually Ammonia. • Ammonia causes cuticle to swell and separate

  5. Variables of this Experiment

  6. Materials • Materials Needed: • Hair • Containers • Different brands of hair dye • Gloves • Microscope • 10ml Measuring cylinder • Timer • Weights and Coins • Retort stand • Scotch tape • Electronic beam balance • 15-centimetre ruler • Scissors

  7. Procedure • Cut five sets (one set as the control and four sets for the four different hair dyes) of 10 strands of hair. • Hair was dyed according to the manufacturer’s instruction. • When the time is up for all the dyed hair, it is dried and kept in different containers for easy reference. • After the dying process, we checked the number of breaks. The amount of hair breaks were recorded. • Then we hang weights on the hair to test for tensile strength. They are secured one by one. This was continued until the hair breaks. The mass that each hair could hold was recorded. 40X Magnification

  8. Results Analysis and Discussion

  9. Conclusion Dyed hair have a decrease in tensile strength; increase in hair breaks. We conclude, L’Oreal hair dye is the best brand of hair dye Our hypothesis (as mentioned earlier) does not stand. We found out that there is no relationship between the tensile strength and the number of breaks on human hair.

  10. Reflections Learnt to cross compare and compile the information. Able to research smartly and summarize it in our own words. Learnt how to read data and collate them into graphs. Such experience equips us with scientific skills that we can use in future experiments Able to interpret raw data into results, and learnt proper techniques to present these ideas into a scientific report

  11. Thank You!

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