Waterproof Material using Fly-Ash
Researchers at IIT Hyderabad have developed a cheap waterproof material by coating fly ash. As Fly ash is extremely water-loving, it can be turned into water-repellant material after using stearic acid.
Stearic acid has two parts -
Stearic acid has two parts -
- hydrophilic part is called the head
- hydrophobic part is called the tail
Hydrophilic part binds to fly ash particles, the water repelling part remains free. Fly ash varies in size. It is of 100 nms to 1 microns. The stearic-acid coated fly ashes surface can be made to behave like one of the two water-repelling materials -rose petals or lotus leaves.
In case of a rose petal, the surface repels the water but at the same time the structure of the petal ensures that the water droplets stick fast to it.
In case of lotus leaf, water droplets rolls off easily.
Dr.Atul Suresh Deshpande (Department of Material Science and Metallurgical Engineering) says "When we used particles of more or less uniform size, the inter-particle space is more and watewr penetrates and stick to the surface like in the case of a rose petal and remains sticky to the surface even when we titled it to 90 and 180 degrees".
The topography (the arrangement of the natural and artificial physical features of an area) changes completelyt when fly ash particles of different sizes are used. The smaller particles fill up the gap between particles and results tighter packing.
Dr.Mudrika Khandelwal (IIT Hyderabad) says "Air pockets tend to form when the gap between particles reduces making it difficult for water to get into the gaps. Water droplets are suspended on top of the air pockets and so has less sticky to the surface. So when the surface is titled slightly (5 degree) the droplets tend to roll off easily.
Urbashi Mahanta (PHD Student) says " By using a combination of stearic acid and surface roughness we were able to achieve superhydrophobicity".
Dr. Deshpande says "We used a simple process of particle distribution to achieve the two types of hydrophobicity. The extent of hydrophobicity increased in both surfaces when the drying temperature was increased from 60 degree C to 80 degree C. The melting point of stearic acid is over 69 degree so when heated to 80 degree C the surfactant melts leading to better coverage and therefore smoother surface compared with samples treated to 60 degree C. Samples with tight and loose packing when treated to 80 degree C showed more hydrophobicity. The stearic acid coated fly ash can be usedd as a water proofing material. Owing to its hydrophobic nature, the surface can be easily cleaned. One can use an adhesive to apply the stearic acid coated fly ash on a surface".
These kind of inventions will motivate all of us to do something new and in low price.
In case of a rose petal, the surface repels the water but at the same time the structure of the petal ensures that the water droplets stick fast to it.
In case of lotus leaf, water droplets rolls off easily.
Dr.Atul Suresh Deshpande (Department of Material Science and Metallurgical Engineering) says "When we used particles of more or less uniform size, the inter-particle space is more and watewr penetrates and stick to the surface like in the case of a rose petal and remains sticky to the surface even when we titled it to 90 and 180 degrees".
The topography (the arrangement of the natural and artificial physical features of an area) changes completelyt when fly ash particles of different sizes are used. The smaller particles fill up the gap between particles and results tighter packing.
Dr.Mudrika Khandelwal (IIT Hyderabad) says "Air pockets tend to form when the gap between particles reduces making it difficult for water to get into the gaps. Water droplets are suspended on top of the air pockets and so has less sticky to the surface. So when the surface is titled slightly (5 degree) the droplets tend to roll off easily.
Urbashi Mahanta (PHD Student) says " By using a combination of stearic acid and surface roughness we were able to achieve superhydrophobicity".
Dr. Deshpande says "We used a simple process of particle distribution to achieve the two types of hydrophobicity. The extent of hydrophobicity increased in both surfaces when the drying temperature was increased from 60 degree C to 80 degree C. The melting point of stearic acid is over 69 degree so when heated to 80 degree C the surfactant melts leading to better coverage and therefore smoother surface compared with samples treated to 60 degree C. Samples with tight and loose packing when treated to 80 degree C showed more hydrophobicity. The stearic acid coated fly ash can be usedd as a water proofing material. Owing to its hydrophobic nature, the surface can be easily cleaned. One can use an adhesive to apply the stearic acid coated fly ash on a surface".
These kind of inventions will motivate all of us to do something new and in low price.
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