Exhibit 4.40

This Agreement, dated May 12, 2011, by and between Dais Analytic Corporation (hereinafter referred to as “Company”), a New York corporation, having its principal place of business at 11552 Prosperous Drive, Odessa, FL 33556 and RBC Capital Markets Corporation- Custodian for Leonard Samuels IRA, a Minnesota corporation, with an address of 510 Marquette Avenue, M09-Alternative Investments, Minneapolis, MN 55402 (hereinafter referred to as “RBC”). Company and RBC are also both hereinafter referred to individually as “Party” and together as the “Parties”.

WITNESSETH:

WHEREAS, on February 19, 2010 Company issued RBC a promissory note in the principal amount of Six Hundred and Twenty Thousand Dollars ($620,000), as amended (“Note”); and

WHEREAS, RBC desires to apply all proceeds due and payable under the Note to the purchase of Two Million Six Hundred Sixty Seven Thousand Five Hundred and Three (2,667,503) shares of Company’s $.01 Par value common stock (“Common Stock”) subject to the terms and conditions contained herein; and

WHEREAS, on or about December 20, 2007 and December 31, 2007, the Company issued to RBC warrants (the “2007 Warrants”) to purchase up to 1,500,000 and 1,250,000 shares; respectively, of the Common Stock, par value $0.01 per share, of the Company (the “Common Stock”);

WHEREAS, on or about October 15, 2009, the Company issued to RBC a warrant (the “2009 Warrant”) to purchase up to 275,000 shares of Common Stock; and

WHEREAS, the Company and RBC have agreed, subject to the terms and conditions set forth herein, to amend the terms of the 2007 Warrants and the 2009 Warrant; and

WHEREAS, the Company and RBC have further agreed that, in accordance with the terms set forth herein, and in consideration of purchasing the above shares, the Company will issue to RBC a warrant (“Warrant”) to purchase up to 962,500 shares of Common Stock.

NOW THEREFORE, in consideration of the mutual premises, representations, warranties, covenants and agreements contained herein, and intending to be legally bound hereby, the Parties hereto agree as follows:

IN WITNESS WHEREOF, the Parties have executed this Agreement as of the day and the year first hereinabove written.

EXHIBIT A

AMENDMENT TO 2007 WARRANTS

This AMENDMENT TO 2007 WARRANTS is dated as of May 12, 2011, by and between Dais Analytic Corporation, a New York corporation (the “Company”), and RBC Capital Markets - Custodian for Leonard Samuels IRA (“RBC”).

WHEREAS, the Company issued to RBC Stock Purchase Warrants, dated as of December 20, 2007 and December 31,2007 (the “2007 Warrants”), on or about December 20, 2007 and December 31, 2007; and

WHEREAS, the parties desire to amend the 2007 Warrants as is set forth herein.

NOW, THEREFORE, the parties hereto agree as follows:

1. Amendment to Exercise Provisions. The 2007s Warrant shall be deemed amended to add the following as Section 13:

14. Cashless Exercise. Notwithstanding any provisions herein to the contrary if (i) the Per Share Market Value (as defined below) of one share of Common Stock is greater than the Exercise Price (at the date of calculation as set forth below) and (ii) a registration statement under the Securities Act providing for the resale of the Warrant Shares is not then in effect, in lieu of exercising this Warrant by payment of cash, the Holder may exercise this Warrant by a cashless exercise and shall receive the number of shares of Common Stock equal to an amount (as determined below) by surrender of this Warrant at the principal office of the Company together with the properly endorsed Exercise Agreement in which event the Company shall issue to the Holder a number of shares of Common Stock computed using the following formula:

For purposes hereof, “Per Share Market Value” means on any particular date (a) the last closing bid price per share of the Common Stock on such date on the OTC Bulletin Board or another registered national stock exchange on which the Common Stock is then listed, or if there is no such price on such date, then the closing bid price on such exchange or quotation system on the date nearest preceding such date, or (b) if the Common Stock is not listed then on the OTC Bulletin Board or any registered national stock exchange, the last closing bid price for a share of Common Stock in the over-the-counter market, as reported by the OTC Bulletin Board or in the National Quotation Bureau Incorporated or similar organization or agency succeeding to its functions of reporting prices) at the close of business on such date, or (c) if the Common Stock is not then reported by the OTC Bulletin Board or the National Quotation Bureau Incorporated (or similar organization or agency succeeding to its functions of reporting prices), then the “Pink Sheet” quotes for the applicable trading days preceding such date of determination, or (d) if the Common Stock is not then publicly traded the fair market value of a share of Common Stock as determined by an independent appraiser selected in good faith by the Holder and reasonably acceptable to the Company.

2. Continuing Effect. Except as otherwise set forth herein, the 2007 Warrants remain unamended and in full force and effect.

IN WITNESS WHEREOF, the parties hereto have executed this Amendment to 2007 Warrant as of the 12th day of May, 2011.

EXHIBIT B

AMENDMENT TO 2009 WARRANT

This AMENDMENT TO 2009 WARRANT is dated as of May 12, 2011, by and between Dais Analytic Corporation, a New York corporation (the “Company”), and RBC Capital Markets- Custodian for Leonard Samuels IRA (“RBC”).

WHEREAS, the Company issued to RBC the Stock Purchase Warrant, dated as of October 15,2009 (the “2009 Warrant”), on or about October 15, 2009; and

WHEREAS, the parties desire to amend the 2009 Warrant as is set forth herein.

NOW, THEREFORE, the parties hereto agree as follows:

1. Amendment to Exercise Provisions. The 2009 Warrant shall be deemed amended to add the following as Section 14:

14. Cashless Exercise. Notwithstanding any provisions herein to the contrary if (i) the Per Share Market Value (as defined below) of one share of Common Stock is greater than the Exercise Price (at the date of calculation as set forth below) and (ii) a registration statement under the Securities Act providing for the resale of the Warrant Shares is not then in effect, in lieu of exercising this Warrant by payment of cash, the Holder may exercise this Warrant by a cashless exercise and shall receive the number of shares of Common Stock equal to an amount (as determined below) by surrender of this Warrant at the principal office of the Company together with the properly endorsed Exercise Agreement in which event the Company shall issue to the Holder a number of shares of Common Stock computed using the following formula:

For purposes hereof, “Per Share Market Value” means on any particular date (a) the last closing bid price per share of the Common Stock on such date on the OTC Bulletin Board or another registered national stock exchange on which the Common Stock is then listed, or if there is no such price on such date, then the closing bid price on such exchange or quotation system on the date nearest preceding such date, or (b) if the Common Stock is not listed then on the OTC Bulletin Board or any registered national stock exchange, the last closing bid price for a share of Common Stock in the over-the-counter market, as reported by the OTC Bulletin Board or in the National Quotation Bureau Incorporated or similar organization or agency succeeding to its functions of reporting prices) at the close of business on such date, or (c) if the Common Stock is not then reported by the OTC Bulletin Board or the National Quotation Bureau Incorporated (or similar organization or agency succeeding to its functions of reporting prices), then the “Pink Sheet” quotes for the applicable trading days preceding such date of determination, or (d) if the Common Stock is not then publicly traded the fair market value of a share of Common Stock as determined by an independent appraiser selected in good faith by the Holder and reasonably acceptable to the Company.

2. Continuing Effect. Except as otherwise set forth herein, the 2009 Warrant remains unamended and in full force and effect.

IN WITNESS WHEREOF, the parties hereto have executed this Amendment to 2009 Warrant as of the 12th day of May, 2011.