Wednesday fact: Why doesn't paper money disintegrate when it gets washed in the washing machine?
Normal paper — including notebook paper, newspaper, construction paper — is all made out of cellulose, which comes from trees. The trees are chemically broken down into their individual wood fibers, and the cellulose fibers are chosen and formed into very thin sheets to create paper.
Paper money can survive the washing machine because it’s made of rags, not cellulose. Paper money, on the other hand, is made from paper made of rags. Cotton or linen fabric is beaten to create cotton or linen fibers. You have probably heard of “rag paper” or “fine linen writing paper.” This is where it comes from.
It turns out that rag fibers bond together much more firmly than fibers in regular paper. Rag fibers are basically unaffected by water, whereas cellulose fibers absorb water and come apart when they get wet. So paper money comes through the washer just fine, while cellulose paper comes unglued.
Why are polysaccharides not sweet?
Due to the fact that I have taken Biology as an AS subject, I heard my classmate ask this question: what is cotton made up of? When the teacher replied with cellulose, they said: so why isn’t it sweet, if glucose is the basic unit?
I do recall that polysaccharides are not sweet, but the reason behind it, I did not know, until I made some research:
This is the structure of glucose, as you see, it has ‘OH’ groups sticking out. Certain orientations of these ‘OH’ groups react with the tongue receptors, which is the reason why they are sweet.
In contrast, cellulose has glycosidic bonds ‘O-C-O’
You can make out that it is made of many glucose units which have condensed, losing their ‘OH’ groups, which used to be responsible for the sweetness.
Scientists make artificial “zero-calorie” or whatever sugars by adding ‘OH’ groups at a certain orientation to synthetic molecules.
You might have figured out that I was not content with the answer: it has a different structure :)
Bug's Opinion: Second generation of biofuels
Many considered hopes are now being pinned on the second generation of biofuels. The introduction of the first generation of biofuels was seen by the production of sugar cane, starch and oils of food crops as biofuels and although they very much economically viable limiting factors have reduced them to being inefficient in the long run. However the second generation of biofuels promises more efficiency, although costs are yet to be considered. Cellulose from agricultural and urban waste, wood chips and other non-food biomass sources promises these ideas.
This cellulosic biomass would either undergo enzyme hydrolysis into sugars for fermentation into alcohol, or Firsher-Tropsch gasification into synthesis gas for processing by catalysis into liquids that could be used to make fuels or even feedstock. It is no doubt that this generation will create a much bigger impact towards stopping global-warming and we will become less dependent on fossil fuels. However there are many uncertainties relating to the economical viability and environmental compatibility. To do so this will require a much greater effort from government subsidies and financial supporting parties.
It is very important that this generation of biofuels plays a huge role in mitigating climate change. For any technology to do so it is important that they have the potential to become commercially available within the next 10-20years; unless the emission of green house gases reduces or technologies or a policy is introduced to shift to a low carbon society, a mass extinction event would be unavoidable. It must be proved that they have the potential of reducing large-scale emissions at global levels, once life-cycle emissions of all greenhouse gases have been considered but yet to be done so at micro-level. If this technology directly or indirectly destroys ecosystems which play an essential role in the Earths carbon cycle then its risk is accelerating and not extenuating global warming. However there is no substantial evidence that the second generation biofuels will satisfy either criterion. These technical barriers must be overcome in the foreseeable future. Much of the cellulosic ethanol investment is going into genetic engineering without any risk assessment in place. At the same the Fisher-Tropsch Biodiesel gasification is facing different hurdles. Although many hopes by scientists and politicians are being set on this future generation, there has been no assessment of the consequences of using large amounts of biomass from ‘plant-waste’. Perennial crop plantations on food production on ecosystems, global greenhouse gasses, soil fertility or water supplies have not been accounted for. We yet, wait for evidence proving the large scale second generation of biofuels is either, sustainable or environmentally friendly.
misery4evr replied to your photo: ‘Black Bean water and Onion Skin water used for…’ does this work only on cellulosic fiber?
Well, no matter what the fiber is, you must mordant it before you dye it. That involves either soaking the fabric in iron, alum, rhubarb or pomegranate skins. The mordant has it’s own process of preparation. The fabric will also react differently to the dye based on how you mordant it beforehand.
Once properly mordanted, different fibers will take to different natural dyes based on their own properties as well as how you’ve prepared the dyes.
I’ve learned now that natural animal fibers take better to natural dyes because, like wool or our hair for instance, the fibers are made up of microscopic scales. When those scales are heated, they open up, allowing the dye to fully saturate the fiber. This includes silk as well, as a good animal fiber for dying.
Cellulose can also be dyed with natural dyes, i.e. Cotton, hemp, bamboo, etc. But it doesn’t seem to take to dyes as well as the animal fibers.