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Improving the colloidal stability of temperature-sensitive poly(N-isopropylacrylamide) solutions using low molecular weight hydrophobic additives
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SYSNO ASEP 0494383 Druh ASEP J - Článek v odborném periodiku Zařazení RIV J - Článek v odborném periodiku Poddruh J Článek ve WOS Název Improving the colloidal stability of temperature-sensitive poly(N-isopropylacrylamide) solutions using low molecular weight hydrophobic additives Tvůrce(i) Velychkivska, Nadiia (UMCH-V) RID, ORCID
Starovoytova, Larisa (UMCH-V) RID
Březina, V. (CZ)
Hanyková, L. (CZ)
Hill, J. P. (JP)
Labuta, J. (JP)Zdroj.dok. ACS Omega. - : American Chemical Society - ISSN 2470-1343
Roč. 3, č. 9 (2018), s. 11865-11873Poč.str. 9 s. Jazyk dok. eng - angličtina Země vyd. US - Spojené státy americké Klíč. slova smart polymers ; poly(N-isopropylacrylamide) ; phase separation Vědní obor RIV CD - Makromolekulární chemie Obor OECD Polymer science Institucionální podpora UMCH-V - RVO:61389013 UT WOS 000446186000153 EID SCOPUS 85053866947 DOI 10.1021/acsomega.8b01811 Anotace Poly(N-isopropylacrylamide) (PNIPAM) is an important polymer with stimuli-responsive properties, making it suitable for various uses. Phase behavior of the temperature-sensitive PNIPAM polymer in the presence of four low-molecular weight additives tert-butylamine (t-BuAM), tert-butyl alcohol (t-BuOH), tert-butyl methyl ether (t-BuME), and tert-butyl methyl ketone (t-BuMK) was studied in water (D2O) using high-resolution nuclear magnetic resonance (NMR) spectroscopy and dynamic light scattering. Phase separation was thermodynamically modeled as a two-state process which resulted in a simple curve which can be used for fitting of NMR data and obtaining all important thermodynamic parameters using simple formulas presented in this paper. The model is based on a modified van’t Hoff equation. Phase separation temperatures Tp and thermodynamic parameters (enthalpy and entropy change) connected with the phase separation of PNIPAM were obtained using this method. It was determined that Tp is dependent on additives in the following order: Tp(t-BuAM) > Tp(t-BuOH) > Tp(t-BuME) > Tp(t-BuMK). Also, either increasing the additive concentration or increasing pKa of the additive leads to depression of Tp. Time-resolved 1H NMR spin–spin relaxation experiments (T2) performed above the phase separation temperature of PNIPAM revealed high colloidal stability of the phase-separated polymer induced by the additives (relative to the neat PNIPAM/D2O system). Small quantities of selected suitable additives can be used to optimize the properties of PNIPAM preparations including their phase separation temperatures, colloidal stabilities, and morphologies, thus improving the prospects for the application. Pracoviště Ústav makromolekulární chemie Kontakt Eva Čechová, cechova@imc.cas.cz ; Tel.: 296 809 358 Rok sběru 2019
Počet záznamů: 1