table.dataTable thead th.sorting:after {
    font-family: "Material Icons";
    content: "unfold_more";
    padding-left: 0.5em;
    vertical-align: middle !important;
}

table.dataTable thead .sorting_asc:after {
    font-family: "Material Icons";
    content: "expand_less";
    padding-left: 0.5em;
    vertical-align: middle !important;
}

table.dataTable thead .sorting_desc:after {
    font-family: "Material Icons";
    content: "expand_more";
    padding-left: 0.5em;
    vertical-align: middle !important;
}