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Bakirov A, Kopishev E, Kadyrzhan K, Donbaeva E, Zhaxybayeva A, Duisembiyev M, Suyundikova F, Suleimenov I. The Method of Direct and Reverse Phase Portraits as a Tool for Systematizing the Results of Studies of Phase Transitions in Solutions of Thermosensitive Polymers. Gels 2024; 10:395. [PMID: 38920941 PMCID: PMC11203281 DOI: 10.3390/gels10060395] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2024] [Revised: 05/29/2024] [Accepted: 06/07/2024] [Indexed: 06/27/2024] Open
Abstract
It is shown that a more than significant amount of experimental data obtained in the field of studying systems based on thermosensitive hydrophilic polymers and reflected in the literature over the past decades makes the issue of their systematization and classification relevant. This, in turn, makes relevant the question of choosing the appropriate classification criteria. It is shown that the basic classification feature can be the number of phase transition stages, which can vary from one to four or more depending on the nature of the temperature-sensitive system. In this work, the method of inverse phase portraits is proposed for the first time. It was intended, among other things, to identify the number of phase transition stages. Moreover, the accuracy of this method significantly exceeds the accuracy of the previously used method of direct phase portraits since, for the first time, the operation of numerical differentiation is replaced by the operation of numerical integration. A specific example of the application of the proposed method for the analysis of a previously studied temperature-sensitive system is presented. It is shown that this method also allows for a quantitative comparison between the results obtained by the differential calorimetry method and the turbidimetry method. Issues related to increasing the resolution of the method of direct phase portraits are discussed.
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Affiliation(s)
- Akhat Bakirov
- Department of Chemistry and Technology of Organic Substances, Natural Compounds and Polymers, Faculty of Chemistry and Chemical Technology, Al Farabi Kazakh National University, Almaty 050040, Kazakhstan;
- Department of Telecommunication Engineering, Institute of Communications and Space Engineering, Gumarbek Daukeev Almaty University of Power Engineering and Communications, Almaty 050040, Kazakhstan;
| | - Eldar Kopishev
- Department of Chemistry, Faculty of Natural Sciences, L.N. Gumilyov Eurasian National University, Astana 010000, Kazakhstan; (E.D.); (A.Z.); (M.D.); (F.S.)
| | - Kaisarali Kadyrzhan
- Department of Telecommunication Engineering, Institute of Communications and Space Engineering, Gumarbek Daukeev Almaty University of Power Engineering and Communications, Almaty 050040, Kazakhstan;
| | - Elvira Donbaeva
- Department of Chemistry, Faculty of Natural Sciences, L.N. Gumilyov Eurasian National University, Astana 010000, Kazakhstan; (E.D.); (A.Z.); (M.D.); (F.S.)
| | - Aigerim Zhaxybayeva
- Department of Chemistry, Faculty of Natural Sciences, L.N. Gumilyov Eurasian National University, Astana 010000, Kazakhstan; (E.D.); (A.Z.); (M.D.); (F.S.)
| | - Marat Duisembiyev
- Department of Chemistry, Faculty of Natural Sciences, L.N. Gumilyov Eurasian National University, Astana 010000, Kazakhstan; (E.D.); (A.Z.); (M.D.); (F.S.)
| | - Faiziya Suyundikova
- Department of Chemistry, Faculty of Natural Sciences, L.N. Gumilyov Eurasian National University, Astana 010000, Kazakhstan; (E.D.); (A.Z.); (M.D.); (F.S.)
| | - Ibragim Suleimenov
- National Engineering Academy of the Republic of Kazakhstan, Almaty 050010, Kazakhstan
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Application of the liquid-liquid dispersed microextraction based on phase transition behavior of temperature sensitive polymer to rapidly detect 5 BPs in food packaging. Food Chem 2020; 347:128960. [PMID: 33461116 DOI: 10.1016/j.foodchem.2020.128960] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2020] [Revised: 12/05/2020] [Accepted: 12/23/2020] [Indexed: 01/17/2023]
Abstract
In this paper, temperature sensitive polymer p(MAH-β-CD-co-NIPAM) was used as extraction in DLLME, because its phase transition behavior can be observed at room temperature due to Hofmeister and non-co-solvent effect. The whole pretreatment process is simple and fast, and the extraction process did not require dispersant to assist dispersion and centrifugation to collect the adsorbent. A new analytical method based on DLLME coupled with HPLC-UV was developed to detect five types of BPs in milk and take-out packaging. The limits of detection ranged from 0.44 to 1.60 ng mL-1 (S/N = 3). The relative recoveries of 5 BPs in food packaging were in the range of 91.08-108.04%.
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