<SEC-DOCUMENT>0000933430-19-000005.txt : 20190515
<SEC-HEADER>0000933430-19-000005.hdr.sgml : 20190515
<ACCEPTANCE-DATETIME>20190515172827
ACCESSION NUMBER:		0000933430-19-000005
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20190513
FILED AS OF DATE:		20190515
DATE AS OF CHANGE:		20190515

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			WHITMORE BRADFORD T
		CENTRAL INDEX KEY:			0000933430
		STATE OF INCORPORATION:			IL
		FISCAL YEAR END:			1231

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	000-22333
		FILM NUMBER:		19829796

	MAIL ADDRESS:	
		STREET 1:		1603 ORRINGTON AVE., STE 900
		CITY:			EVANSTON
		STATE:			IL
		ZIP:			60201

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			NANOPHASE TECHNOLOGIES Corp
		CENTRAL INDEX KEY:			0000883107
		STANDARD INDUSTRIAL CLASSIFICATION:	MISCELLANEOUS PRIMARY METAL PRODUCTS [3390]
		IRS NUMBER:				363687863
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		1319 MARQUETTE DRIVE
		CITY:			ROMEOVILLE
		STATE:			IL
		ZIP:			60446
		BUSINESS PHONE:		6303231200

	MAIL ADDRESS:	
		STREET 1:		1319 MARQUETTE DRIVE
		CITY:			ROMEOVILLE
		STATE:			IL
		ZIP:			60446

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	NANOPHASE TECHNOLOGIES CORPORATION
		DATE OF NAME CHANGE:	19970305
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>primary_doc.xml
<DESCRIPTION>PRIMARY DOCUMENT
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0306</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2019-05-13</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0000883107</issuerCik>
        <issuerName>NANOPHASE TECHNOLOGIES Corp</issuerName>
        <issuerTradingSymbol>NANX</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0000933430</rptOwnerCik>
            <rptOwnerName>WHITMORE BRADFORD T</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>1603 ORRINGTON AVE., STE 900</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>EVANSTON</rptOwnerCity>
            <rptOwnerState>IL</rptOwnerState>
            <rptOwnerZipCode>60201</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2019-05-13</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>P</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>4189000</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0.4</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>17096435</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>2433300</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                    <footnoteId id="F1"/>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>by Grace Brothers, LP</value>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>601410</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                    <footnoteId id="F2"/>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>by Grace Investments, LP</value>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>51454</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>by daughter</value>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">As manager of BRO-GP, LLC, Grace Brothers, LP's General Partner, Bradford T. Whitmore is an indirect beneficial owner of 2,433,300 shares of Common Stock.</footnote>
        <footnote id="F2">As manager of INV-GP, LLC, Grace Investments, LP's General Partner, Bradford T. Whitmore is an indirect beneficial owner of 601,410 shares of Common Stock.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>Bradford T. Whitmore</signatureName>
        <signatureDate>2019-05-15</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
