I don't think this is a question you should ask yourself, but you should talk to your employer about. I don't see any brick-layers practising new brick laying techniques in their spare time, or car mechanics expected to find out about new cars and engines at the weekend. Obviously you have interests, and you like to know about the latest news or craze but this should be a recreational activity (ten minutes here and there). If blogging, research and trying new technology benefits your work then it should be supported by your employer.
Incidentally I am a full-time senior engineer with two kids and many years experience. You shouldn't be expected to juggle like this.