Registration No. 333- As filed with the Securities and Exchange Commission on November 21, 2023 UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM S-1 REGISTRATION STATEMENT UNDER THE SECURITIES ACT OF 1933 NANOPHASE TECHNOLOGIES CORPORATION (Exact name of registrant as specified in its charter) (State or other jurisdiction of incorporation or organization) Delaware 3390 36-3687863 (Primary Standard Industrial Classification Code Number) (I.R.S. Employer Identification Number) 1319 ...