In jQuery, check whether you have hit the bottom of page using scroll function. Once you hit that, make an ajax call (you can show a loading image here till ajax response) and get the next set of data, append it to the div. This function gets executed as you scroll down the page again.
$(window).scroll(function() {
if($(window).scrollTop() == $(document).height() - $(window).height()) {
// ajax call get data from server and append to the div
}
});