Once you have the call number for a book, use the library's maps to find your items. Library website > About > Floor plans and maps
You can either search for "library catalog only" (which is a quick way of finding books, but it's less accurate) or do a general search and filter to the Resource Type books (recommended)
It depends on the subtopic, but generally speaking, nanotechnology books are in the "T" section:
is the Library of Congress classification for nanotechnology books.
This puts the books next to other books about technology and engineering (but note: not chemistry or physics).