Love of the new mobile phone I trouble to bring back (9)
I believe the answer is:
neophilia
'love of the new' is the definition.
(neophilia is a love of new things)
'mobile phone i trouble to bring back' is the wordplay.
'mobile' is an anagram indicator.
'trouble' becomes 'ail' (synonyms).
'to bring back' says the letters should be written in reverse.
'ail' in reverse letter order is 'lia'.
'phone' is an anagram of 'neoph'.
'neoph'+'i'+'lia'='NEOPHILIA'
(Other definitions for neophilia that I've seen before include "Love for the recent" , "Liking for new things" .)