Transcript Absorbency of water, acid and base in common household products Jessica Abrams
Absorbency of water, acid and base in common household products
Jessica Abrams
What determines Absorbency?
Surface Area: Larger surface area = greater absorbency.
Porosity: Higher porosity = greater absorbency.
Molecular Structure of Textile: Hydrophilic or hydrophobic
Initial Theory/Model
Water will absorb into a material if there is room for it. Some materials have more room than others. Variable is described as porosity.
Since different materials are made of different organic and synthetic constituents, the nature of these constituents will affect a material’s absorption.
Porosity
The amount of space in a material For example, sponges are more porous than dish towels.
Material Constituents
Hydrophobic
– Lack of areas on the individual molecules of the material that can bond with the dissociated molecules of water.
Hydrophilic
– Locations on molecules of material that can bond with dissociated molecules of water.
Molecular Structure
Cotton
:
Polyester
:
Initial Theory/Model
Part I
: Materials with high porosity will absorb more water than materials with low porosity.
Part II
: Materials with more free H + will absorb more base than water, and materials with more OH will absorb more acid than water.
Methods
Acquired five different types of household materials and cut into 2 x 2” squares.
Then…
• Acquired 3 % acetic acid (vinegar) and 3 % base (hydrogen peroxide) • Measured the weight of each item.
• Added water, acid or base to each item and weighed again • Conducted three trials for each item using acid, water and base.
• Calculated fluid absorption per gram of weight.
Porosities of Fabrics
Higher Porosity 100% Polyester 100% Cotton Cotton/ Poly Acrylic Lower Porosity Flannel Paper Towel
Results – Part I
30 25 20 15 10 5 0 100% cotton 100% ploy Acrylic Fleece Cotton/Poly Cotton (Flannel) Paper Towel 100% Polyester absorbed more water per gram than other textiles Materials with high porosity absorbed more water than those with low porosity.
Results – Part II
100% Cotton
25 20 15 10 Acid Water 5 0
More base absorbed than water.
Base
100% Polyester
30 25 20 15 10 5 Acid Water Base 0
Absorbed more water than acid.
No significant difference between water and base.
Cotton/Poly Blend
1 0 3 2 5 4 7 6 Acid Water Base
No significant difference in the absorption of acid, water or base by the cotton/polyester blend.
Cotton (Flannel)
1 0 3 2 5 4 7 6 Acid Water Base
Slightly more base absorbed than acid and water
.
Paper Towel
4.5
4 3.5
3 2.5
2 1.5
1 0.5
0 Acid Water Base Absorbed more acid and base than water.
No significant difference between acid absorption and base absorption.
Support for Claim I
Claim: Textiles with high porosity will absorb more water than textiles with low porosity.
Support: From graph 1, we saw that materials with high porosity absorbed more water than those with low porosity.
30 25 20 15 10 5 0 100% cotton 100% poly Acrylic Fleece Cotton/Poly Cotton (Flannel) Paper Towel
Porosity vs. Absorption
Material 100% Polyester 100% Cotton Acrylic Fleece Cotton/Poly Cotton Flannel Paper Towel Porosity Highest Lowest Absorption(mL/g) 23.73
17.12
10.04
5.67
4.92
1.96
Support for Claim II
Claim
: Textiles with more free H + will absorb more base than water, and textiles with more OH will absorb more acid than water
Support:
Three of the five materials tested absorbed acid and or base to a greater or lesser extent.
Experimental Evidence - Polyester
• Polyester absorbed more water than acid. • The decrease in acid absorption shows that the polyester molecule has difficulty bonding with excess H + bonds. • This makes sense when we consider that the molecular structure of polyester has more free H+ than OH .
Polyester
• Polyester has more free H + bonds than OH bonds. This means that it would bond more base (OH ) than acid (H + ).
Experimental Evidence - Cotton
• Both the high porosity cotton and the cotton flannel differentially absorbed base.
• 100% Cotton: more base than water • Cotton Flannel: more base than water and acid.
• In both circumstances, the materials absorbed base preferentially.
• This makes sense when we consider the molecular structure of cotton.
•Cotton has slightly more H + bonds than OH bonds.
•This may cause it to preferentially take up base which has an excess of OH .
Assumptions
Molecular bonding of water/acid/base with material results in a significant difference in weight.
Individual samples of material were significantly uniform in porosity.
Weights of vinegar, hydrogen peroxide and water are of similar mass.
Final Model
Absorption
Material Constituents More H+ Absorbed more base Hydrophillic More OH No conclusion Hydrophobic Hight Absorbed more water Porosity Low Absorbed less water