a clean , high efficiency , low pressure drop , adsorptive filter material that is porous and includes an acidic functional group . the filter can include , for example , a non - woven filter composite has a porous sulfonated divinyl benzene styrene copolymer beads having sulfonic acid functional side groups . the non - woven filter is used to remove molecular bases , including ammonia , organic amines , inides , aminoalcohols , alcoholoamines from the atmosphere used in semiconductor fabrication and other processes that require uncontaminated gaseous environments of high quality .