function emoji_encode($nickname){

    $strEncode = '';

        $length = mb_strlen($nickname,'utf-8');

         for ($i=0; $i < $length; $i++) {

                     $_tmpStr = mb_substr($nickname,$i,1,'utf-8');

              if(strlen($_tmpStr) >= 4){

                             $strEncode .= rawurlencode($_tmpStr);

              }else{

                             $strEncode .= $_tmpStr;

              }

        }

     return $strEncode;

}