Influence of Tacticity on the Structure Formation of Poly(methacrylic acid) in Langmuir/Langmuir–Blodgett and Thin Films

Hasan, Nazmul; Nguyen, Thi Minh Hai; Busse, Karsten; Kreßler, Jörg

doi:10.1002/macp.202200428

Cited by 4 publications

(5 citation statements)

References 56 publications

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“…However, AGC‐MAA with high MAA content (85 mol%) has higher surface roughness (66 nm) and relatively bigger size (300–400 nm). This is understandable due to the hydrophobicity of methacrylic units and, as a result, the tendency of particles to formation of large aggregates 34 …”

Section: Resultsmentioning

confidence: 99%

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Novel biocidal polyampholytes with guanidinium and carboxy groups

Gorbunova,

Zagumennova,

Lemkina

2023

Polymers for Advanced Techs

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Polyampholytes are a promising class of multifunctional polymers containing both cationic and anionic groups. By varying the total charge of the copolymers, it is possible to significantly change the properties of the target macromolecule, such as molecular weight, solubility, reactivity, etc. In an attempt to create new polyampholytes, here the radical copolymerization of 2,2‐diallyl‐1,1,3,3‐tetraethylguanidinium chloride (AGC) with acrylic (AA), methacrylic (MAA), vinylacetic (VAA), and crotonic (CA) acids in bulk and in organic solvents has been studied and described. The relative reactivity of the unsaturated acids in the radical copolymerization with AGC in bulk appears to be MAA > AA > CA > VAA. It is shown that both AGC double bonds participate in copolymerization with unsaturated acids, forming a cyclolinear polymer chain including cis/trans‐stereoisomeric pyrrolidinium subunits. The kinetics of this polymerization has been studied. The possibility and prospects of chemical modifications of copolymers by drugs bearing an amino group are considered. Moreover, the copolymers under study, including the guanidinium moiety, are effective against Gram‐positive and Gram‐negative bacteria.

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Section: Resultsmentioning

confidence: 99%

“…This is understandable due to the hydrophobicity of methacrylic units and, as a result, the tendency of particles to formation of large aggregates. 34…”

Section: The Surface Morphology Of Polyampholyte Thin Filmsmentioning

confidence: 99%

Novel biocidal polyampholytes with guanidinium and carboxy groups

Gorbunova,

Zagumennova,

Lemkina

2023

Polymers for Advanced Techs

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“…AFM reveals the presence of small droplets in the dried nanoemulsion with a dimension ranging from ~10 to 50 nm with an average height of ~2 nm. The actual morphology of the nanoemulsion is hard to resolve due to the soft or sticky nature of the droplets which generate artifacts and become deformed during imaging [ 48 ]. Hence, a typical core shell-like structure of o/w droplets was not observed in the height images or even in other imaging modes (e.g., adhesion or modulus).…”

Section: Resultsmentioning

confidence: 99%

Synthesis and Characterization of Dimeric Artesunate Glycerol Monocaprylate Conjugate and Formulation of Nanoemulsion Preconcentrate

et al. 2023

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Malaria is one of the major life-threatening health problems worldwide. Artesunate is the most potent antimalarial drug to combat severe malaria. However, development of drug resistance, short plasma half-life, and poor bioavailability limit the efficacy of this drug. Here, we applied the dimerization concept to synthesize dimeric artesunate glycerol monocaprylate conjugate (D-AS-GC) by conjugating artesunate (AS) with glycerol monocaprylate (GC) via esterification reaction. D-AS-GC conjugate, AS, and GC were well characterized by 1H NMR, attached proton test (APT) 13C NMR and 2D NMR spectroscopy. D-AS-GC conjugate was further analyzed by ESI-TOF MS. Finally, a series of nanoemulsion preconcentrate (F1–F6) of D-AS-GC was prepared by mixing different ratios of oil and surfactant/cosurfactant and evaluated after dilution with an aqueous phase. The optimized formulation (F6) exhibits a clear nanoemulsion and the hydrodynamic diameter of the dispersed phase was determined by DLS and DOSY NMR spectroscopy. The morphology of the nanoemulsion droplets of F6 was investigated by AFM, which revealed the formation of tiny nanoemulsion droplets on a hydrophilic mica substrate. Moreover, using a less polar silicon wafer led to the formation of larger droplets with a spherical core shell-like structure. Overall, the rational design of the dimeric artesunate-based nanoemulsion preconcentrate could potentially be used in more efficient drug delivery systems.

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“…Hasan et al [31] investigated the influence of tacticity of the structure formation of Poly(methacrylic acid) by defining an isotactic polymer as consisting only of meso diads (m), with two adjacent configurational repeating units with identical orientation, whereas a syndiotactic polymer is made up of only racemo diads (r), with two adjacent configurational repeating units with the opposite orientation, while an atactic polymer contains both m and r diads in a random sequence. With this definition, the tacticity can be further described even more precisely with the introduction of higherorder sequences than diads such, tetrads, and pentads [31].…”

Section: Introductionmentioning

confidence: 99%

Effect of Tacticity on London Dispersive Surface Energy, Polar Free Energy, and Lewis Acid-Base Surface Energies of Poly Methyl Methacrylate by Inverse Gas Chromatography

Hamieh

2024

Preprint

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This research was devoted to study the effect of the tacticity of PMMA on the surface physicochemical properties such as the London dispersive component of the surface energy of the polymer, the polar and dispersive free energies, the Lewis’s acid-base surface parameters, and the Lewis acid and base surface energies of atactic, isotactic and syndiotactic PMMAs as a function of the temperature. Inverse gas chromatography (IGC) at infinite dilution was used to determine the surface thermodynamic properties of PMMA at different tacticities. The experimental values of the net retention time and volume of model organic molecules adsorbed on the atactic, isotactic and syndiotactic PMMAs, were obtained by IGC technique at infinite dilution. The London dispersion interaction energy was used for the separation of the polar and dispersive energy of the different n-alkanes and polar solvents adsorbed on the different PMMA surfaces. The London dispersive surface energy γ_s^d (T) of PMMAs was determined by applying the Hamieh thermal model that took into account the effect of the temperature on the surface area of adsorbed molecules. The obtained results showed non-linear variations of γ_s^d (T) of atactic, isotactic, and syndiotactic PMMAs with three maxima characterizing the three transition temperatures of PMMAs, T_g, T_g and T_(liq-liq) with a shift of these temperatures with the isotactic and syndiotactic PMMAs. It was showed that the polar interaction free energy ∆G_a^p (T) also showed the presence of the three above transition temperatures of the polymers. The study showed an important non-linearity variation of the different acid-base parameters in the various polymer surfaces proving the highest effect of the temperature and the tacticity on these parameters. The determination of the enthalpic and entropic Lewis’s acid-base parameters showed an amphoteric character for the different PMMAs. The basicity of the atactic PMMA was about four times larger than its acidity outside the neighborhood of the transition temperatures of the polymer. Whereas, the isotactic PMMA was about 2 to 2.5 times more basic than acid, while the syndiotactic PMMA exhibited the highest basicity by showing a surface 5 to 8 times more basic than acid. However, the Lewis acid-base parameters strongly depended on the temperature and sudden variations of these surface parameters were observed around the transition temperatures largely depending on the PMMA tacticity. The determination of the polar acid and base surface energies of the three PMMAs led to the same previous transition temperatures with an important effect of the tacticity of PMMA on the values of these acid-base surface energies.

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Influence of Tacticity on the Structure Formation of Poly(methacrylic acid) in Langmuir/Langmuir–Blodgett and Thin Films

Cited by 4 publications

References 56 publications

Novel biocidal polyampholytes with guanidinium and carboxy groups

Novel biocidal polyampholytes with guanidinium and carboxy groups

Synthesis and Characterization of Dimeric Artesunate Glycerol Monocaprylate Conjugate and Formulation of Nanoemulsion Preconcentrate

Effect of Tacticity on London Dispersive Surface Energy, Polar Free Energy, and Lewis Acid-Base Surface Energies of Poly Methyl Methacrylate by Inverse Gas Chromatography

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