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Dan Y, Luo H, Gong P, Yan D, Niu Y, Li G. Structural, energetic and dynamic investigation of poly(ethylene oxide) in imidazolium-based ionic liquids with different cationic structures. Phys Chem Chem Phys 2023; 25:29783-29796. [PMID: 37886855 DOI: 10.1039/d3cp01946b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2023]
Abstract
In this work, two imidazolium-based ionic liquids (ILs) with different cations including dications (DIL) and monocations (MIL) were blended with poly(ethylene oxide) (PEO). The influence of ILs' structure on the structural and dynamic properties of a PEO/IL system was investigated by molecular dynamics (MD) simulation and density functional theory (DFT) methods. The simulation results show that DIL exhibits weaker interaction with PEO than MIL due to a stronger IL aggregation effect. The intermolecular interaction also makes the PEO chain tend to organize around the imidazolium ring of ILs, which causes the conformational entropy loss. Compared with PEO/MIL, this phenomenon is more significant in PEO/DIL because of the double positive centers of the dication and a longer hydrogen bond lifetime. MD simulation also demonstrates that DIL could act as a "crosslinker" to promote the formation of a physical crosslinking network which has strong dependence on the concentration of IL. The competition between physical crosslinking and plasticizing effects induces non-monotonic variations of relaxation time in PEO/DIL, which is consistent with its unusual change of the glass transition temperature (Tg). Despite stronger hydrogen bonding interactions between PEO and MIL demonstrated by atom-in-molecules (AIM) and reduced density gradient (RDG) analysis, the segmental mobility is slower in PEO/DIL according to the MSD curve. These differences in multiple structural or energetic factors finally lead to different conductive mechanisms and hence obtain different ionic conductivities.
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Affiliation(s)
- Yongjie Dan
- College of Polymer Science and Engineering, State Key Laboratory of Polymer Materials Engineering of China, Sichuan University, Chengdu 610065, China.
| | - Huan Luo
- School of Automation, Chengdu University of Information Technology, Chengdu, China
| | - Pengjian Gong
- College of Polymer Science and Engineering, State Key Laboratory of Polymer Materials Engineering of China, Sichuan University, Chengdu 610065, China.
| | - Dadong Yan
- Department of Physics, Beijing Normal University, Beijing 100875, China
| | - Yanhua Niu
- College of Polymer Science and Engineering, State Key Laboratory of Polymer Materials Engineering of China, Sichuan University, Chengdu 610065, China.
| | - Guangxian Li
- College of Polymer Science and Engineering, State Key Laboratory of Polymer Materials Engineering of China, Sichuan University, Chengdu 610065, China.
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Lukáš Petrova S, Vragović M, Pavlova E, Černochová Z, Jäger A, Jäger E, Konefał R. Smart Poly(lactide)- b-poly(triethylene glycol methyl ether methacrylate) (PLA- b-PTEGMA) Block Copolymers: One-Pot Synthesis, Temperature Behavior, and Controlled Release of Paclitaxel. Pharmaceutics 2023; 15:pharmaceutics15041191. [PMID: 37111676 PMCID: PMC10143907 DOI: 10.3390/pharmaceutics15041191] [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: 03/08/2023] [Revised: 03/31/2023] [Accepted: 04/06/2023] [Indexed: 04/29/2023] Open
Abstract
This paper introduces a new class of amphiphilic block copolymers created by combining two polymers: polylactic acid (PLA), a biocompatible and biodegradable hydrophobic polyester used for cargo encapsulation, and a hydrophilic polymer composed of oligo ethylene glycol chains (triethylene glycol methyl ether methacrylate, TEGMA), which provides stability and repellent properties with added thermo-responsiveness. The PLA-b-PTEGMA block copolymers were synthesized using ring-opening polymerization (ROP) and reversible addition-fragmentation chain transfer (RAFT) polymerization (ROP-RAFT), resulting in varying ratios between the hydrophobic and hydrophilic blocks. Standard techniques, such as size exclusion chromatography (SEC) and 1H NMR spectroscopy, were used to characterize the block copolymers, while 1H NMR spectroscopy, 2D nuclear Overhauser effect spectroscopy (NOESY), and dynamic light scattering (DLS) were used to analyze the effect of the hydrophobic PLA block on the LCST of the PTEGMA block in aqueous solutions. The results show that the LCST values for the block copolymers decreased with increasing PLA content in the copolymer. The selected block copolymer presented LCST transitions at physiologically relevant temperatures, making it suitable for manufacturing nanoparticles (NPs) and drug encapsulation-release of the chemotherapeutic paclitaxel (PTX) via temperature-triggered drug release mechanism. The drug release profile was found to be temperature-dependent, with PTX release being sustained at all tested conditions, but substantially accelerated at 37 and 40 °C compared to 25 °C. The NPs were stable under simulated physiological conditions. These findings demonstrate that the addition of hydrophobic monomers, such as PLA, can tune the LCST temperatures of thermo-responsive polymers, and that PLA-b-PTEGMA copolymers have great potential for use in drug and gene delivery systems via temperature-triggered drug release mechanisms in biomedicine applications.
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Affiliation(s)
- Svetlana Lukáš Petrova
- Institute of Macromolecular Chemistry CAS, Heyrovského nám. 2, 162 06 Prague, Czech Republic
| | - Martina Vragović
- Institute of Macromolecular Chemistry CAS, Heyrovského nám. 2, 162 06 Prague, Czech Republic
| | - Ewa Pavlova
- Institute of Macromolecular Chemistry CAS, Heyrovského nám. 2, 162 06 Prague, Czech Republic
| | - Zulfiya Černochová
- Institute of Macromolecular Chemistry CAS, Heyrovského nám. 2, 162 06 Prague, Czech Republic
| | - Alessandro Jäger
- Institute of Macromolecular Chemistry CAS, Heyrovského nám. 2, 162 06 Prague, Czech Republic
| | - Eliézer Jäger
- Institute of Macromolecular Chemistry CAS, Heyrovského nám. 2, 162 06 Prague, Czech Republic
| | - Rafał Konefał
- Institute of Macromolecular Chemistry CAS, Heyrovského nám. 2, 162 06 Prague, Czech Republic
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Linn JD, Liberman L, Neal CAP, Calabrese MA. Role of chain architecture in the solution phase assembly and thermoreversibility of aqueous PNIPAM/silyl methacrylate copolymers. Polym Chem 2022; 13:3840-3855. [PMID: 37193094 PMCID: PMC10181847 DOI: 10.1039/d2py00254j] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Stimuli-responsive polymers functionalized with reactive inorganic groups enable creation of macromolecular structures such as hydrogels, micelles, and coatings that demonstrate smart behavior. Prior studies using poly(N-isopropyl acrylamide-co-3-(trimethoxysilyl)propyl methacrylate) (P(NIPAM-co-TMA)) have stabilized micelles and produced functional nanoscale coatings; however, such systems show limited responsiveness over multiple thermal cycles. Here, polymer architecture and TMA content are connected to the aqueous self-assembly, optical response, and thermo-reversibility of two distinct types of PNIPAM/TMA copolymers: random P(NIPAM-co-TMA), and a 'blocky-functionalized' copolymer where TMA is localized to one portion of the chain, P(NIPAM-b-NIPAM-co-TMA). Aqueous solution behavior characterized via cloud point testing (CPT), dynamic light scattering (DLS), and variable-temperature nuclear magnetic resonance spectroscopy (NMR) demonstrates that thermoresponsiveness and thermoreversibility over multiple cycles is a strong function of polymer configuration and TMA content. Despite low TMA content (≤2% mol), blocky-functionalized copolymers assemble into small, well-ordered structures above the cloud point that lead to distinct transmittance behaviors and stimuli-responsiveness over multiple cycles. Conversely, random copolymers form disordered aggregates at elevated temperatures, and only exhibit thermoreversibility at negligible TMA fractions (0.5% mol); higher TMA content leads to irreversible structure formation. This understanding of the architectural and assembly effects on the thermal cyclability of aqueous PNIPAM-co-TMA can be used to improve the scalability of responsive polymer applications requiring thermoreversible behavior, including sensing, separations, and functional coatings.
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Affiliation(s)
- Jason D Linn
- Department of Chemical Engineering and Materials Science, University of Minnesota Twin Cities, 421 Washington Ave SE, Minneapolis, MN 55455, USA
| | - Lucy Liberman
- Department of Chemical Engineering and Materials Science, University of Minnesota Twin Cities, 421 Washington Ave SE, Minneapolis, MN 55455, USA
| | - Christopher A P Neal
- Department of Chemical Engineering and Materials Science, University of Minnesota Twin Cities, 421 Washington Ave SE, Minneapolis, MN 55455, USA
| | - Michelle A Calabrese
- Department of Chemical Engineering and Materials Science, University of Minnesota Twin Cities, 421 Washington Ave SE, Minneapolis, MN 55455, USA
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Khalil M, Fahmi A, Nizardo NM, Amir Z, Mohamed Jan B. Thermosensitive Core-Shell Fe 3O 4@poly( N-isopropylacrylamide) Nanogels for Enhanced Oil Recovery. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2021; 37:8855-8865. [PMID: 34242029 DOI: 10.1021/acs.langmuir.1c01271] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
An investigation on the application of thermosensitive core-shell Fe3O4@PNIPAM nanogels in enhanced oil recovery was successfully performed. Here, the unique core-shell architecture was fabricated by conducting the polymerization at the surface of 3-butenoic acid-functionalized Fe3O4 nanoparticles and characterized using X-ray diffraction (XRD), 1H NMR, vibration sample magnetometer (VSM), and high-resolution transmission electron microscopy (HR-TEM). According to the results, this core-shell structure was beneficial for achieving the desired high viscosity and low nanofluid mobility ratio at high temperatures, which is essential for enhanced oil recovery (EOR) application. The results demonstrated that the nanogels exhibited a unique temperature-dependent flow behavior due to the PNIPAM shell's ability to transform from a hydrated to a dehydrated state above its low critical solution temperature (LCST). At such conditions, the nanogels exhibited a significantly low mobility ratio (M = 0.86), resulting in an even displacement front during EOR and leads to higher oil production. Based on the result obtained from sand pack flooding, about 25.75% of an additional secondary oil recovery could be produced when the nanofluid was injected at a temperature of 45 °C. However, a further increase in the flooding temperature could result in a slight reduction in oil recovery due to the precipitation of some of the severely aggregated nanogels at high temperatures.
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Affiliation(s)
- Munawar Khalil
- Department of Chemistry, Faculty of Mathematics and Natural Sciences, Universitas Indonesia, 16424 Depok, West Java, Indonesia
| | - Alwy Fahmi
- Department of Chemistry, Faculty of Mathematics and Natural Sciences, Universitas Indonesia, 16424 Depok, West Java, Indonesia
| | - Noverra Mardhatillah Nizardo
- Department of Chemistry, Faculty of Mathematics and Natural Sciences, Universitas Indonesia, 16424 Depok, West Java, Indonesia
| | - Zulhelmi Amir
- Department of Chemical Engineering, Faculty of Engineering, University of Malaya, 50603 Kuala Lumpur, Malaysia
| | - Badrul Mohamed Jan
- Department of Chemical Engineering, Faculty of Engineering, University of Malaya, 50603 Kuala Lumpur, Malaysia
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Zhan T, Xie H, Mao J, Wang S, Hu Y, Guo Z. Conductive PNIPAM/CMCS/MWCNT/PANI hydrogel with temperature, pressure and pH sensitivity. ChemistrySelect 2021. [DOI: 10.1002/slct.202101003] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Tianyu Zhan
- State Key Laboratory for Managing Biotic and Chemical Threats to the Quality and Safety of Agro-products, State Key Laboratory Base of Novel Functional Materials and Preparation Science School of Materials Science and Chemical Engineering, Ningbo University Ningbo 315211 People's Republic of China
| | - Houpeng Xie
- State Key Laboratory for Managing Biotic and Chemical Threats to the Quality and Safety of Agro-products, State Key Laboratory Base of Novel Functional Materials and Preparation Science School of Materials Science and Chemical Engineering, Ningbo University Ningbo 315211 People's Republic of China
| | - Jie Mao
- Department of Basic Zhejiang Pharmaceutical College Ningbo, Zhejiang Province 315000 China
| | - Sui Wang
- State Key Laboratory for Managing Biotic and Chemical Threats to the Quality and Safety of Agro-products, State Key Laboratory Base of Novel Functional Materials and Preparation Science School of Materials Science and Chemical Engineering, Ningbo University Ningbo 315211 People's Republic of China
| | - Yufang Hu
- State Key Laboratory for Managing Biotic and Chemical Threats to the Quality and Safety of Agro-products, State Key Laboratory Base of Novel Functional Materials and Preparation Science School of Materials Science and Chemical Engineering, Ningbo University Ningbo 315211 People's Republic of China
| | - Zhiyong Guo
- State Key Laboratory for Managing Biotic and Chemical Threats to the Quality and Safety of Agro-products, State Key Laboratory Base of Novel Functional Materials and Preparation Science School of Materials Science and Chemical Engineering, Ningbo University Ningbo 315211 People's Republic of China
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Van Gheluwe L, Chourpa I, Gaigne C, Munnier E. Polymer-Based Smart Drug Delivery Systems for Skin Application and Demonstration of Stimuli-Responsiveness. Polymers (Basel) 2021; 13:1285. [PMID: 33920816 PMCID: PMC8071137 DOI: 10.3390/polym13081285] [Citation(s) in RCA: 38] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2021] [Revised: 04/11/2021] [Accepted: 04/12/2021] [Indexed: 12/15/2022] Open
Abstract
Progress in recent years in the field of stimuli-responsive polymers, whose properties change depending on the intensity of a signal, permitted an increase in smart drug delivery systems (SDDS). SDDS have attracted the attention of the scientific community because they can help meet two current challenges of the pharmaceutical industry: targeted drug delivery and personalized medicine. Controlled release of the active ingredient can be achieved through various stimuli, among which are temperature, pH, redox potential or even enzymes. SDDS, hitherto explored mainly in oncology, are now developed in the fields of dermatology and cosmetics. They are mostly hydrogels or nanosystems, and the most-used stimuli are pH and temperature. This review offers an overview of polymer-based SDDS developed to trigger the release of active ingredients intended to treat skin conditions or pathologies. The methods used to attest to stimuli-responsiveness in vitro, ex vivo and in vivo are discussed.
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Affiliation(s)
| | | | | | - Emilie Munnier
- EA 6295 Nanomédicaments et Nanosondes, Faculté de Pharmacie, Université de Tours, 31 Avenue Monge, 37200 Tours, France; (L.V.G.); (I.C.); (C.G.)
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Martinez-Moro M, Jenczyk J, Giussi JM, Jurga S, Moya SE. Kinetics of the thermal response of poly(N-isopropylacrylamide co methacrylic acid) hydrogel microparticles under different environmental stimuli: A time-lapse NMR study. J Colloid Interface Sci 2020; 580:439-448. [PMID: 32711195 DOI: 10.1016/j.jcis.2020.07.049] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2020] [Revised: 07/08/2020] [Accepted: 07/10/2020] [Indexed: 11/28/2022]
Abstract
HYPOTHESIS Hydrogels of N-isopropylacrylamide and methacrylic acid (P(NIPAm-co-MAA)) display pH sensitivity and complex positively charged molecules through carboxylate groups, while having a critical solution temperature at which they reduce in volume and dehydrate. We aimed to elucidate how the responsiveness of MAA to environmental changes alters PNIPAm hydrogels at the molecular level using nuclear magnetic resonance (NMR). Time-lapse NMR allows us to follow the evolution of NMR signal under a temperature stimulus, providing unique information on conformational freedom of the hydrogel polymers. EXPERIMENTS We used time-lapse NMR to follow the evolution of the NMR signal with time over a temperature change from 25 to 40°C and to study the swelling/deswelling kinetics of P(NIPAm-co-MAA) microgels at different pH values and ionic strengths, and in the presence of positively charged molecules complexing carboxylate groups. FINDINGS At acid pH, hydrogel collapse is favored over neutral pH, and at basic pH the carboxylates remain steadily hydrated during temperature increase. Increasing ionic strength results in a faster, more effective collapse than decreasing pH. Complexation of medium-sized molecules with several charges (spermine, spermidine) causes a faster collapse than complexation with large molecular weight poly(allylamine) hydrochloride, but similar to the collapse effected by large poly(diallyldimethylammonium) chloride. This work opens new perspectives to using time-lapse NMR to study thermoresponsive systems that respond to multiple stimuli, with particular relevance in designing hydrogels for drug delivery.
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Affiliation(s)
- Marta Martinez-Moro
- Center for Cooperative Research in Biomaterials (CIC biomaGUNE), Basque Research and Technology Alliance (BRTA), Paseo de Miramon 182 C, 20014 Donostia-San Sebastian, Spain
| | - Jacek Jenczyk
- NanoBioMedical Centre, Adam Mickiewicz University, Wszechnicy Piastowskiej 3, 61-614 Poznań, Poland.
| | - Juan M Giussi
- Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas (INIFTA), Departamento de Química, Facultad de Ciencias Exactas, Universidad Nacional de La Plata, CONICET, La Plata 1900, Argentina
| | - Stefan Jurga
- NanoBioMedical Centre, Adam Mickiewicz University, Wszechnicy Piastowskiej 3, 61-614 Poznań, Poland
| | - Sergio E Moya
- Center for Cooperative Research in Biomaterials (CIC biomaGUNE), Basque Research and Technology Alliance (BRTA), Paseo de Miramon 182 C, 20014 Donostia-San Sebastian, Spain.
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Konefał R, Černoch P, Konefał M, Spěváček J. Temperature Behavior of Aqueous Solutions of Poly(2-oxazoline) Homopolymer and Block Copolymers Investigated by NMR Spectroscopy and Dynamic Light Scattering. Polymers (Basel) 2020; 12:E1879. [PMID: 32825475 PMCID: PMC7565327 DOI: 10.3390/polym12091879] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2020] [Revised: 08/17/2020] [Accepted: 08/18/2020] [Indexed: 11/16/2022] Open
Abstract
1H NMR methods in combination with dynamic light scattering were applied to study temperature behavior of poly(2-isopropyl-2-oxazoline) (PIPOx) homopolymer as well as PIPOx-b-poly(2-methyl-2-oxazoline) (PMeOx) and poly(2-ethyl-2-oxazoline) (PEtOx)-b-PMeOx diblock copolymers in aqueous solutions. 1H NMR spectra showed a different way of phase transition for the main and side chains in PIPOx-based solutions. Additionally, the phase transition is irreversible for PIPOx homopolymer and partially reversible for PIPOx-b-PMeOx copolymer. As revealed by NMR, the phase transition in PEtOx-based copolymers solutions exists despite the absence of solution turbidity. It is very broad, virtually independent of the copolymer composition and reversible with some hysteresis. Two types of water molecules were detected in solutions of the diblock copolymers above the phase transition-"free" with long and "bound" with short spin-spin relaxation times T2. NOESY spectra revealed information about conformational changes observed already in the pre-transition region of PIPOx-b-PMeOx copolymer solution.
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Affiliation(s)
- Rafał Konefał
- Institute of Macromolecular Chemistry CAS, Heyrovského nám. 2, 162 06 Prague 6, Czech Republic; (P.Č.); (M.K.)
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Konefał R, Spěváček J, Mužíková G, Laga R. Thermoresponsive behavior of poly(DEGMA)-based copolymers. NMR and dynamic light scattering study of aqueous solutions. Eur Polym J 2020. [DOI: 10.1016/j.eurpolymj.2020.109488] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
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Es Sayed J, Lorthioir C, Perrin P, Sanson N. PEGylated NiPAM microgels: synthesis, characterization and colloidal stability. SOFT MATTER 2019; 15:963-972. [PMID: 30652180 DOI: 10.1039/c8sm02156b] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
The objective of this work is to synthesize highly stable thermoresponsive microgels that could be used in diverse applications. To achieve this, N-isopropylacrylamide (NiPAM) based microgels were first synthesized by surfactant-free precipitation polymerization of NiPAM in the presence of poly(ethylene glycol)methacrylate (PEG) as a macro-comonomer and methylenebisacrylamide (MBA) as a chemical crosslinker. By combining a complete set of techniques such as dynamic light scattering (DLS), scanning electron microscopy (SEM), zetametry, 1H NMR and micro-differential scanning calorimetry (μDSC), we clearly demonstrate that (i) the incorporation of the PEG chains controls the size and the polydispersity of the NiPAM-based microgels, whereas the thermal behavior in solution (enthalpy, volume phase transition temperature (VPTT)) remains almost the same as for pure NiPAM microgels; (ii) the PEG chains are mainly located on the microgel periphery; and (iii) the presence of the PEG chains strongly increases the colloidal stability of microgels in electrolyte solutions at high temperatures.
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Affiliation(s)
- Julien Es Sayed
- Soft Matter Sciences and Engineering, ESPCI Paris, PSL University, Sorbonne Université, CNRS, F-75005 Paris, France.
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Baddam V, Aseyev V, Hietala S, Karjalainen E, Tenhu H. Polycation–PEG Block Copolymer Undergoes Stepwise Phase Separation in Aqueous Triflate Solution. Macromolecules 2018. [DOI: 10.1021/acs.macromol.8b01810] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Affiliation(s)
- Vikram Baddam
- Department of Chemistry, PB 55, University of Helsinki, Helsinki FIN-00014, Finland
| | - Vladimir Aseyev
- Department of Chemistry, PB 55, University of Helsinki, Helsinki FIN-00014, Finland
| | - Sami Hietala
- Department of Chemistry, PB 55, University of Helsinki, Helsinki FIN-00014, Finland
| | - Erno Karjalainen
- Department of Chemistry, PB 55, University of Helsinki, Helsinki FIN-00014, Finland
| | - Heikki Tenhu
- Department of Chemistry, PB 55, University of Helsinki, Helsinki FIN-00014, Finland
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Effect of N-isopropylacrylamide thermoresponsive blocks on the rheological properties of water-soluble thermoassociative copolymers synthesized via RAFT polymerization. Colloid Polym Sci 2018. [DOI: 10.1007/s00396-018-4391-y] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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13
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Konefał R, Spěváček J, Černoch P. Thermoresponsive poly(2-oxazoline) homopolymers and copolymers in aqueous solutions studied by NMR spectroscopy and dynamic light scattering. Eur Polym J 2018. [DOI: 10.1016/j.eurpolymj.2018.01.019] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
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