1、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 wil
2、l 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 materials absorption.,Porosity,The amount
3、 of space in a materialFor 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 dissociat
4、ed 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 th
5、an 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
6、 using acid, water and base. Calculated fluid absorption per gram of weight.,Porosities of Fabrics,Higher Porosity Lower Porosity100% 100% Cotton/ Acrylic Flannel Paper Polyester Cotton Poly Towel,Results Part I,100% Polyester absorbed more water per gram than other textiles,Materials with high poro
7、sity absorbed more water than those with low porosity.,Results Part II,More base absorbed than water.,Absorbed more water than acid.,No significant difference between water and base.,No significant difference in the absorption of acid, water or base by the cotton/polyester blend.,Slightly more base
8、absorbed than acid and water.,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
9、 high porosity absorbed more water than those with low porosity.,Porosity vs. Absorption,Material Porosity Absorption(mL/g) 100% Polyester Highest 23.73 100% Cotton 17.12 Acrylic Fleece 10.04 Cotton/Poly 5.67 Cotton Flannel 4.92 Paper Towel Lowest 1.96,Support for Claim II,Claim: Textiles with more
10、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 a
11、bsorption 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-) tha
12、n 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
13、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,Happy Holidays!,
