Пробовал несколько способов:
$Family=volonterFamily;
$Name=volonterName;
$NameFamily=(string)$Name+(string)$Family;
$this->title = $model->$NameFamily;
error //ответ на выдаче
$Family=volonterFamily;
$Name=volonterName;
$NameFamily=$Name+$Family;
$this->title = $model->$NameFamily;
error //ответ на выдаче
//volonterFamily;
//volonterName;
$this->title = $model->volonterFamily & volonterName;
P"@ @A@ A //ответ на выдаче
//volonterFamily;
//volonterName;
$this->title = $model->volonterFamily+volonterName;
0 //ответ на выдаче
//volonterFamily;
//volonterName;
$this->title = $model->volonterFamily and volonterName;
volonterFamily //ответ на выдаче