RefWorks is a popular easy-to-use citation management application but has limited options for working with PDFs. At the moment it is not possible to directly import PDFs into a folder. However, in the edit view you can upload the PDF as a file attachment:
The text of PDFs and other file attachments may be searched by selecting Attachments in the Advanced Search/Search Field drop-down menu and entering a search term.
Note that in addition to PDFs a file attachment can be a Word document, an image file or other file types.
For more information on file attachments view this Attachment Feature Fact document.