SUPPLY AGREEMENT

Exhibit 10.56

SUPPLY AGREEMENT

This Supply Agreement (the “Agreement”) is made and entered into by and between NANOPHASE Technologies Corporation, a Delaware corporation, with offices located at 1319 Marquette Drive, Romeoville, Illinois 60446 (“Nanophase”), and Rohm and Haas Electronic Materials CMP Inc., a Delaware corporation, with offices located at 451 Bellevue Road, Newark, Delaware 19713 (“RHEM”), for effectiveness March 23 2009 (“Effective Date”).

WHEREAS, Nanophase and RHEM have mutually consented to terminate the Amended and Restated Cooperation Agreement between them dated August 25, 2006, governing various business transactions, including the parties’ cooperation, Nanophase’s supply, and RHEM’s purchase of certain products made by Nanophase (the “2006 Agreement”);

WHEREAS, Nanophase and RHEM recognize that it is desirable for both parties to ensure the continuous supply of certain products manufactured by Nanophase, and used by RHEM for chemical mechanical planarization (“CMP”) applications, and to continue the parties’ business relationship;

NOW THEREFORE, in consideration of the mutual covenants and agreements herein, sufficiency of which is expressly acknowledged, Nanophase and RHEM hereby agree as follows:

For purposes of this Agreement, “Product(s)” means nanocrystalline cerium oxides particles (“Ceria”) and/or dispersions of Ceria using Nanophase’s proprietary process (“Ceria Particles”) for use by RHEM in products for CMP applications for semiconductor wafers.

This Agreement shall commence on March 23, 2009, and expire on March 23, 2012 (the “Term”), for a term of three (3) years. Unless terminated by either party by giving the other party a written notice at least ninety (90) days prior to the expiration of the Term, the Term of this Agreement is automatically renewed for another two (2) years upon the expiration date.

In the event Nanophase either ceases its entire business operation, or the production of the Products, Nanophase shall notify RHEM in writing at least six (6) months prior to the effective date of such event, and RHEM may immediately terminate this Agreement.

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In the event that RHEM either ceases its entire business operation, or the sale of the Products, RHEM shall notify Nanophase in writing at least six (6) months prior to the effective date of such event, and Nanophase may immediately terminate this Agreement.

The parties’ 2006 Agreement shall be terminated immediately upon the start of the Term of this Agreement. However, each party’s respective obligations, rights and liability under Sections 6, 7, 9 and 14 of the 2006 Agreement shall remain in effect. In addition, each party’s respective obligations, rights and liability incurred under this Agreement, prior to its termination date, shall survive the termination of this Agreement.

During the Term of this Agreement, RHEM agrees to buy, and Nanophase agrees to sell to RHEM, the quantity of Products as may be required by RHEM and set forth under purchase orders from RHEM. The purchase orders will contain specifications of Products required by RHEM, including price, payment term, and the manner of delivery (“Purchase Order(s)”).

Nanophase shall directly provide stable supply and sufficient volume of Products required by RHEM as demonstrated by a rolling non-binding six-month forecast provided by RHEM on a quarterly basis. There shall be no requirement on minimum monthly purchase by RHEM.

In the event that the term of a Purchase Order exceeds the Term of this Agreement, then this Agreement will continue to govern the purchase and sale of Products pursuant to such Purchase Order until the Purchase Order expires or is terminated.

The parties’ relationship under this Agreement is intended to be non-exclusive. Accordingly, nothing herein shall require: (a) RHEM to purchase Ceria exclusively from Nanophase, or (b) Nanophase to sample or sell Ceria or its Ceria Particles exclusively to RHEM.

Pricing may be amended by both parties in writing from time to time.

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Nanophase warrants that all Products purchased by RHEM (a) meet all current industry standards with respect to materials and workmanship; (b) conform to the specifications set forth in the applicable Purchase Order, as well as to all of Nanophase’s applicable written specifications, drawings, samples, or other descriptions of the Products and to any further specifications, standards, and/or other criteria agreed upon in writing between the parties; (c) to the best of Nanophase’s knowledge, do not infringe upon any patent or trade secret of any third party, including the processes Nanophase applies in manufacturing and selling the Products; and (d) are and shall be in compliance with all applicable laws, rules and regulations.

TO THE EXTENT ALLOWABLE BY LAW, ALL OTHER WARRANTIES ARE EXCLUDED HEREIN, WITH THIS EXCLUSION EXTENDING TO IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.

In the event Products purchased pursuant to this Agreement do not meet all warranties specified above, RHEM may, in addition to reimbursement of all reasonable damages and entitlement to indemnification from Nanophase (under Section 8 of this Agreement), at its sole discretion, return any nonconforming Products at the cost of Nanophase, for replacement, refund, or credit of the purchase price. In the event RHEM elects to return any Products, the parties will adhere to the following protocol: (a) RHEM will contact Nanophase’s Quality Director and then forward to the Quality Director a sample of the Products that RHEM believes is non-conforming, together with supporting documentation (including any test results); (b) upon receipt of the sample, Nanophase will test it and then notify RHEM of the test results; (c) where the test results confirm that the sample is non-conforming, Nanophase will provide RHEM with Nanophase’s Return Authorization Number (“RAN”); and (d) to the extent possible, all paperwork concerning the returned Products must include Nanophase’s RAN. Nanophase shall arrange and pay for th