abstract |
A moisture absorbent material comprises a porous matrix of adsorbent alumina, the volume of the pores of the matrix being between 60 and 90 %, preferably 80 to 85 % of the volume of the material. The average diameter of the pores is between 5 x 10-9 and 1 x 10-6 m. The pores contain a crystalline deliquescent compound, preferably calcium chloride, in an amount of between 4 and 20 %, preferably between 8 and 12 %, by weight, excluding any water of crystallisation, with respect to the total weight of the material. The absorbent material may be incorporated in a shoe insole and absorbs up to 1.5 ml moisture per gram of dry material whilst generating heat, thereby maintaining the feet of the user both warm and dry. |