Search Results (175)

Poly(2-oxazoline) coatings with antibiofouling properties and good biocompatibility can also be deposited by the plasma polymerization method using 2-methyl-2-oxazoline and 2-ethyl-2-oxazoline as monomers. Plasma polymers are formed of various monomer fragments and recombination products. Commonly, plasma polymers are highly crosslinked structures created by many different fragments, preferably of no repeating unit. Thus, chemical analysis of plasma polymers is difficult. To obtain a better description of plasma polymerized poly(2-oxazoline) coatings, the analysis of their plasma deposition process was performed. The electron ionization of 2-methyl-2-oxazoline and 2-ethyl-2-oxazoline molecules was studied using the crossed electron–molecular beam technique with mass spectrometric detection of the produced ions. The chemical composition of gaseous compounds at plasma polymerization was determined by gas chromatography-mass spectrometry (GC-MS), ion mobility spectrometry (IMS) and optical emission spectroscopy (OES). Also, the chemical composition and antibacterial activity of the water leachates from previously deposited poly(2-oxazoline) films were tested using FTIR spectroscopy and the disk diffusion method, respectively. It was found that acetonitrile and propionitrile are the main neutral products created in the nitrogen discharge with 2-methyl-2-oxazoline and 2-ethyl-2-oxazoline monomers. The water leachates from deposited films do not exhibit any antibacterial activity. It was concluded that the antibacterial properties of POx films are due to their hydrophility. Full article

Alzheimer’s disease is the most widespread neurodegenerative disease in the world. Galantamine hydrobromide (GH) is one of the drugs used to treat mild to moderate dementia of the Alzheimer type. Due to the fact that the specificity of the disease requires maximally facilitated intake, orodispersible films present such an opportunity. In the present study orodispersible films based on poly(2-ethyl-2-oxazoline) as well as partially hydrolyzed poly(2-ethyl-2-oxazoline) were prepared and studied as delivery systems for GH. Two samples of partially hydrolyzed PEtOx were synthesized—one of relatively low degree of hydrolysis and another one of relatively high degree of hydrolysis, and studied by Nuclear Magnetic Resonance (NMR). Cytotoxicity assay was performed that validated the low hydrolyzed derivative as biocompatible polymer that maintained desirable physicochemical characteristics without compromising the safety, thereby it was selected for further research. The films were prepared by the solution casting method and characterized by different methods. FTIR was used to determine the potential interactions between the galantamine molecule and the film components. Based on the Thermogravimetric Analysis (TGA) conducted, it was concluded that all films were sufficiently thermally stable, as the component decomposition stage (after initial solvent removal) began above 180 °C. The polymer films were further characterized with the determination of Shore hardness and the results showed that the films containing glycerol as a plasticizer exhibited higher hardness compared to those with PEG as a plasticizer. The disintegration time of the films was determined visually using Petri dishes and it was found that the films disintegrated within the range of 0.52 to 1.58 min, fully meeting the pharmacopoeial requirements. GH release profiles in PBS at 37 °C were obtained, and it was found that by the second minute, 80–90% of the drug were released from the different films, and the release followed an anomalous diffusion mechanism (Case II). Full article

Bacterial adhesion and the subsequent formation of biofilms and biofouling have significant economic and health impacts across all sectors. They are especially impactful in industrial corrosion, healthcare, food processing, agriculture, and waste and drinking water. Synthetic polymers that resist bacterial adhesion are adaptable to a wide range of applications in all of these fields. While there are many bacteria-resistant polymers, some of the best performing include polyethylene glycol (PEG), poly(oxazoline) (POZ), and zwitterionic polymers, with zwitterionic polymers showing the most promise with reductions in bacteria adhesion up to 99% over controls. This review summarizes the demonstrated bacterial resistance performance of these polymer coatings based on literature published over the last ten years. It also identifies the front runners for preventing bacterial adhesion while providing the critical next steps for widespread adoption of this technology. Full article

This work is part of a current and essential issue aiming to find a solution for the replacement of chromium(VI) and cadmium in the surface treatment process applied to electrical connectors. The application of a protective coating obtained by the sol–gel route proves to be an interesting alternative method and numerous studies describe efficient anticorrosion coatings to protect various metallic alloys. The issue of electrical connectors made of 6061 alloy is to combine anticorrosion protection and electrical conduction, which are antagonistic properties, so multifunctional sol–gel coatings and/or architectures have to be synthesized and shaped on connectors. In this work, several experimental parameters, such as the type of carbon filler, the hydrolysis ratio, the precursors’ introduction order are studied and evaluated to achieve industrial requirements. Thus, aqueous suspensions of carbon fillers have been introduced into sol–gel formulations to give rise to conductive coatings (200–500 mΩ_□) with high anticorrosion properties (500 h NSS resistance), in which thickness is less than 10 microns. The incorporation of organic additives poly(2-ethyl-2-oxazoline) or hydroxypropylmethylcellulose positively impacts the flash point of the sol (>60 °C) making the sol–gel process compatible with the HSE recommendation and the ATEX standard. Full article

The significant waste generated by the fashion industry necessitates sustainable textile recycling strategies. Polyester, made from poly(ethylene terephthalate) (PET), is abundant in post-consumer textiles. Technologies have been developed to convert low-density garment waste into flakes, but the role of color sorting in achieving uniform aesthetics in injection-moldable plastics remains underexplored. This study compares materials extruded from dark color-sorted polyester garment flakes with those from light-color flakes in terms of processability in extrusion and injection molding. The properties examined include melt fluidity, injection molding shrinkage, and mechanical and thermal properties. Commercial chain extenders with anhydride, oxazoline, or epoxide reactive groups were added during extrusion. Interestingly, only dark-colored extruded pellets showed significant degradation, but all the chain extenders allowed melt fluidity to be controlled during reprocessing. The bisoxazoline-based additive was the most promising, due to the highly improved ductility of the samples, regardless of whether they were dark-colored or light-colored. The results indicate significant potential for the industrial recycling of post-consumer textiles and highlight the industrial feasibility of repurposing post-consumer polyester garments. This approach not only supports initiatives of circular economy but also offers a viable solution for managing textile waste, particularly in the fashion industry. Additionally, the suggested recycling route combats the production of microplastics. Full article

Poly(2-oxazoline) (POx), a typical thermoresponsive polymer with good biocompatibility, was conjugated with environment-sensitive tetraphenylenethene (TPE) and hydroxyphenylbenzoxazole (HBO) to achieve unique thermometer readings. Through phase transition induced by temperature, the thermometers can measure temperature in biologic range with ratiometric fluorescence response, ultrahigh sensitivity and good reversibility. Moreover, the thermometer can be used to measure the change in temperature with large fluorescence difference in living cells. Full article

Two chiral monooxazolines were synthesized from a secondary amino alcohol, as a key intermediate, isolated in four steps from an isosorbide-derived epoxide. The 2-oxazolines were then obtained through a reaction between this aminoalcohol and an imidate. The new compounds were fully characterized by FTIR, ¹H and ¹³C NMR, and HRMS analyses. Full article

The current demand for heat production via geothermal energy is increasingly rising amid concerns surrounding non-renewable forms of energy. The Dogger aquifer in the Paris Basin (DAPB) in France produces saline geothermal waters (GWs), which are as hot as 70–85 °C, anaerobic, slightly acidic (pH 6.1–6.4), and characterized mainly by the presence of Cl⁻, SO₄²⁻, CO₂/HCO₃⁻, and H₂S/HS⁻. These GWs are corrosive, and the casings of all geothermal wells are carbon steel. Since 1989, these GWs have been progressively treated using petrosourced organic corrosion inhibitors (PS–OCI) at the bottom of the production wells. Currently, there is a great need to test not only new PS–OCIs but also, and above all, biosourced organic corrosion inhibitors (BS–OCIs) to improve the efficiency and environmental friendliness of this carbon-free geothermal energy source. The main objective of this study is to evaluate the potential performance of biosourced corrosion inhibitor candidates (BS–CICs) in terms of their inhibition efficiency (IE) for carbon steel corrosion. This was achieved using a previously established geochemical and electrochemical method to study the mechanisms and kinetics of the corrosion/scaling of carbon steel and optimize short-term corrosion inhibition in standardized reconstituted geothermal water (SRGW) representative of the DAPB’s waters. Four new molecules from the 2-oxazoline family were evaluated individually and compared based on their behavior and inhibition efficiency. These molecules exhibited a mixed nature (i.e., anodic and cathodic inhibitors), with a slight anodic predominance, and showed a significant IE at a concentration of at 10 mg/L during the first hours of immersion of CS-XC38 in SRGW. The average IEs, obtained via the three electrochemical techniques used for the determination of corrosion current densities, i.e., J_corr(Rp), J_corr(Tafel), and J_corr(Rw), are 51%, 79%, 96%, and 93% for Decenox (C10:1), Decanox (C10:0), Undecanox (C11:0), and Tridecanox (C13:0), respectively. Full article

Achieving superior circularly polarized luminescence brightness (B_CPL) is an important subject and continuous challenge for chiroptical materials. Herein, by applying a binary molecular design for the synthesis of chiral organo-Tb³⁺ molecules, a novel pair of mononuclear chiral tris-pyrazolate-Tb³⁺ enantiomers, [Tb(PMIP)₃(R,R-Ph-PyBox)] (2) and [Tb(PMIP)₃(S,S-Ph-PyBox)] (5), have been synthesized and characterized. The three 1-phenyl-3-methyl-4-(isobutyryl)-5-pyrazolone (HPMIP) ligands play the role of efficient luminescence sensitizers and strong light-harvesting antennas, while the enantiopure 2,6-bis(4-phenyl-2-oxazolin-2-yl) pyridine ligand (R,R/S,S-Ph-PyBox) is employed as the strong point-chiral inducer. With the proper combination of the HPMIP and Chiral-Ph-PyBox within the Tb³⁺ enantiomers, strong (PMIP)⁻-centered π-π^* electronic absorption (ε_{263 nm} = 38,400–39,500 M⁻¹ cm⁻¹) and brilliant high-purity ligand-sensitized Tb³⁺-centered green luminescence (Φ_PL = 47–48%) were observed. In addition, a clear circularly polarized luminescence (CPL) activity (|g_lum| = 0.096–0.103) was also observed, resulting in a strong B_CPL (610–623 M⁻¹ cm⁻¹) for the two Tb³⁺ enantiomers from the hypersensitive transitions. Our results offer an effective path to develop high-performance chiroptical organo-Tb³⁺ luminophores. Full article

The coupling between bis(2-oxazolines) and two equivalents of aromatic aldehydes in the presence of catalytic amounts of NiCl₂ affords an ester-imine product in synthetically useful yields. This virtually unknown, 100% atom-economic transformation involves the formal metathesis between the C=N double bond of the bis(2-oxazoline) moiety, which undergoes ring-opening, and the C=O double bond of the aldehyde. The scope of this transformation is studied, and a mechanism is proposed based on DFT calculations. Full article

Conjugated polymers (CPs), in particular poly(p-phenylene vinylene)s (PPVs), are recognized as “smart” materials with potential applications ranging from optoelectronic devices to emergent technologies and to precision medicine. The present communication reports on the synthesis and structural characterization of new dibrominated macromonomers and their derived PPVs, of rod–graft–coil architecture, whose grafted, biocompatible and hydrophilic side chains are either PEG-2000 or poly(2-methyl-2-oxazoline) or poly(2-ethyl-2-oxazoline). The Suzuki–Heck cascade reaction was used for PPVs’ obtainment. After PPVs’ structural characterization using specific techniques (such as ¹H-NMR; GPC), the micellar, fluorescent nanoparticles formed by spontaneous self-assembling during simple direct dissolution in water were evaluated using dynamic light scattering for their size, complementarily combined with Atom Force Microscopy (AFM) for their shape assessing. The PPV micelles’ photophysical properties were revealed using UV-vis spectroscopy and fluorescence measurements. Full article

Nanoparticle adhesion to polymer and similar substrates may be prone to low nano-Newton forces, disrupting the surface bonds and patterning, potentially reducing the functionality of complex surface patterns. Testing this, a functionalised surface reported for biological and medical applications, consisting of a thin plasma-derived oxazoline-based film with 68 nm diameter covalently bound colloidal gold nanoparticles attached within an aqueous solution, underwent nanomechanical analysis. Atomic Force Microscopy nanomechanical analysis was used to quantify the limits of various adaptations to these nanoparticle-featured substrates. Regular and laterally applied forces in the nano-Newton range were shown to de-adhere surface-bound gold nanoparticles. Applying a nanometre-thick overcoating anchored the nanoparticles to the surface and protected the underlying base substrate in a one-step process to improve the overall stability of the functionalised substrate against lower-range forces. The thickness of the oxazoline-based overcoating displayed protection from forces at different rates. Testing overcoating thickness ranging from 5 to 20 nm in 5 nm increments revealed a significant improvement in stability using a 20 nm-thick overcoating. This approach underscores the importance of optimising overcoating thickness to enhance nanoparticle-based surface modifications’ durability and functional integrity. Full article

By using a scaffold hopping/ring equivalent and intermediate derivatization strategies, a series of compounds of 2,5-diphenyl-1,3-oxazoline with substituent changes at the 5-phenyl position were prepared, and their acaricidal activity was studied. However, the synthesized 2,5-diphenyl-1,3-oxazolines showed lower activity against mite eggs and larvae compared to the 2,4-diphenyl-1,3-oxazolines with the same substituents. We speculate that there is a significant difference in the spatial extension direction of the substituents between the two skeletons of compounds, resulting in differences in their ability to bind to the potential target chitin synthase 1. This work is helpful in inferring the internal structure of chitin synthase binding pockets. Full article