Colloid and Polymer Science最新文献

Biodegradable nanocarriers based on polysaccharide-derived amphiphilic copolymers are promising candidates to enhance drug solubility and stability. This study aimed to design a novel amphiphilic carrier based on enzymatic polymerization-derived exopolysaccharides, α-1,3-glucan. Glycosyltransferase I from Streptococcus mutans was used to synthesize α-1,3-glucan, and the amphiphilic α-1,3-glucan-graft-poly(ε-caprolactone) (Glucan-g-PCL) copolymer was synthesized via a homogeneous ring-opening polymerization (ROP) in ionic liquid, 1-butyl-3-methylimidazolium chloride. The chemical structures and physical properties of Glucan-g-PCL copolymer were characterized by FT-IR, ¹H NMR, XRD, and TGA. The self-assembly behavior of the amphiphilic α-1,3-glucan derivative was investigated by fluorescence probe. The results showed that Glucan-g-PCL exhibited a low critical aggregation concentration (CAC) and formed core-shell structured nanostructure via self-assembly. Quercetin (Qu), a hydrophobic active component, was successfully encapsulated within the Glucan-g-PCL micelle-like nanostructure, showing efficient encapsulation and dispersion in water. Qu/Glucan-g-PCL micelle-like nanostructure (Qu/M) was characterized by DLS, TEM, FT-IR, and XRD. FT-IR and XRD analyses showed that Qu was present in an amorphous state in the formulation and without any chemical reactions during the sample preparation procedures. In addition, the antioxidant properties of the Qu/M were investigated using the 2,2-diphenyl-1-picrylhydrazyl (DPPH) method, and significantly improved antioxidant activity was observed for Qu/M compared to Qu/water. The utilization of Glucan-g-PCL nanostructure encapsulation opens up new possibilities for enhancing and expanding the practical applications of quercetin and α-1,3-glucan.

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In this work, polyanion polystyrene sulfonate modified laterite (PML) was used as an excellent material to remove ciprofloxacin (CFX) in water. The CFX adsorption on PML was affected by factors such as pH, PML dosage, contact time, ionic strength, and operating temperature. Under optimum conditions (pH 5; 150 min; 5 mg/mL, 10 mM NaCl, 25 °C) with an initial CFX concentration of 20 ppm, the maximum removal of CFX using PML reached greater than 96%. Langmuir isotherm model provided the best fit to the experimental results of the CFX adsorption process onto PML with the maximum capacity was 10.51 mg/g. Adsorption kinetics were in good agreement with pseudo-second-order. The ∆H⁰ value was − 12.090 kJ.mol⁻¹, and the ∆G⁰ value was − 2.345 kJ.mol⁻¹, declaring that the CFX adsorption onto PML was a spontaneous process and exothermal. Adsorption mechanisms of CFX on PML were controlled by both electrostatic interaction and non-electrostatic interaction. The adsorption constant in the Temkin model was 1.700 J/mol, and the energy value in Dubinin–Radushkevich model was 2.371 kJ/mol, proving that CFX adsorption on PML is a physical adsorption process. After five recycles, the CFX removal was still higher than 77%, while the CFX removal from wastewater was approximately 96%.

Graphical Abstract

In order to solve the problem of poor stability of HPAM (partially hydrolyzed polyacrylamide) gel as a plugging agent at 150 °C, this paper investigates the preparation of a polymer gel strengthened with nano-SiO₂, exhibiting good thermal stability, using a low-cost, low-hydrolysis anionic polymer. The experimental results indicated that when the gel was prepared with 1 wt% HPAM, 1 wt% water-soluble phenolic resin (WSPR) as a crosslinker, and 1 wt% nano-SiO₂ as a stabilizer, the dehydration rate of the gel was less than 5 wt% after 180 days of aging at 150 °C. In order to identify the stability mechanism of nano-SiO₂-strengthened polymer gel, we conducted rheological tests, Cryo-SEM analysis, Fourier transform infrared (FTIR) spectroscopy, and solid-state nuclear magnetic resonance (NMR) analysis on the polymer gel before and after adding nanoparticles. The methods described in the study demonstrate the excellent long-term thermal stability of the polymer gel strengthened with nano-SiO₂ from both chemical bonding and microscopic perspectives. The results of rheological experiments indicated that the addition of nanoparticles improved the yield stress and long-term thermal stability of the gel. The scanning electron microscope (SEM) microstructure analysis confirmed that the addition of nanoparticles resulted in high-density cavities between the microscopic network structures of the gel. This facilitated the trapping of a significant amount of free water and the formation of a stable spatial mechanical support structure, ultimately enhancing the macro-mechanical strength of the gel. Additionally, FTIR and NMR experiments demonstrated that the nanoparticles effectively inhibited the hydrolysis of amide groups to carboxylate, thereby significantly preventing the high-temperature degradation of the gel and maintaining its strength after prolonged aging.

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This research investigated the synthesis of thermoplastic polyurethane (TPU) with a hard segment content (HSC) of 30% weight. The chain extender, the polyols, and the diisocyanate utilized 1,4-butanediol (BDO), and the polycaprolactone diol (PCL-diol) with molecular weights of 2000, 4000, and 10,000 and isophorone diisocyanate (IPDI), respectively. Differential scanning calorimetry (DSC), Fourier-transform infrared spectroscopy (FTIR), hydrogen nuclear magnetic resonance (¹H-NMR), and X-ray diffraction (XRD) were used to examine the chemical microstructure and physical properties of PCL diol and thermoplastic polyurethanes (TPUs). The molecular weight of the PCL diol as soft segments affected the crystallinity and glass transition temperature (T_g) of TPUs. An increase in PCL diol molecular weight resulted in a reduction in elongation at failure and an increase in ultimate tensile strength. This study was conducted to investigate the permeability and the permselectivity of CO₂ and N₂ gases over pressure ranges (3 to 9 atm). It was determined that the gas permeability of each sample increased in response to an increase in the pressure of the supplying gas. An elevation in the molecular weight of PCL-diols in TPU samples resulted in a reduction in selectivity and an increase in CO₂ and N₂ gas permeability. Although IPDI is a non-aromatic cyclic diisocyanate with a significant impact on thermoplastic polyurethane phase morphology, the goal of this paper is to create a change in the molecular weight of PCL-diol and investigate the effect of molecular weight on the resulting morphology as well.

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Abstract

The aim of this research was to investigate spray-dried mebendazole (MBZ)–loaded Soluplus-based polymeric micelles (MBZ@PMs) for improved solubility and bioabsorption upon oral administration. Following the MBZ@PM preparation, the formed micellar preparation was examined using FTIR, PXRD, DSC, and TEM techniques to determine its physical and chemical properties. Critical micelle concentration determination studies showed that Soluplus® can effectively generate stable polymeric micelles. Particle size analysis demonstrated spherical shape and a particle size of 538.7 ± 2.129 nm. Solubility studies demonstrated approximately eight times higher solubility of MBZ@PMs vis-à-vis MBZ in PBS pH 6.8 (90.16 ± 2.54 µg/mL v/s 11.97 ± 2.99 µg/mL). Stability studies confirmed that the size distribution and polydispersity index of the prepared polymeric micelles showed negligible variations. In vitro release studies revealed low MBZ release from MBZ@PMs (9.70 ± 3.2% in 2 h) at pH 1.2 and sustained (33.3 ± 3.9%) at PBS pH 6.8 in 48 h. In vivo pharmacokinetic studies showed approximately fourfold higher bioavailability (AUC_0-ꝏ 153.81 ± 24.20 v/s 38.20 ± 5.55) and 1.5-fold extended half-life of MBZ from MBZ@PMs (2.13 ± 0.53 v/s 1.44 ± 0.36). Therefore, these unprecedented Soluplus®-based polymeric micelles of Mebendazole can be applied as a potential carrier system to improve the therapeutic efficacy of poorly water-soluble compounds.

Abstract

Biodegradable green composites of poly(butylene succinate) (PBS) and poly(L-lactide) (PLA) fibers were initially melt-blended aiming to obtain balanced comprehensive properties. According to the morphological observations, the PLA fibers were uniformly embedded in the PBS matrix. Rheology measurements suggested that the incorporation of PLA fibers improved the viscoelasticity of PBS melt. The percolation network of PLA fibers was formed at content of 20 wt%. The presence of PLA fibers inhibited the crystallization and reduced the isothermal crystallization rate of PBS in the composites. Moreover, the reinforcing effect of PLA fibers on the PBS matrix was found to be very significant. The storage modulus and tensile modulus of the composite with 30 wt% PLA fibers were 74% and 94% higher than those of neat PBS, respectively. PBS/PLA fiber composites prepared by simple melt blending method displayed the combination of enhanced melt strength and modulus, while maintaining the biodegradability of PBS matrix, which is of great potential for the wider practical application of environmentally friendly polymers.

Based on the rate-dependent non-aging constitutive model and the rate-independent aging constitutive model, a rate-dependent aging constitutive model is proposed to explain the changes in mechanical properties of ethylene propylene diene monomer (EPDM) rubber under different strain rates and aging states. In order to simulate the actual use state of rubber, accelerated aging tests are conducted on the samples in a hot air aging environment. The grey wolf algorithm is utilized to accurately fit the engineering stress–strain curve obtained from the experiment, obtaining specific coefficient values that represent the effects of strain rate, aging time, and aging temperature in the constitutive model. The results confirm the effectiveness of the proposed rate-dependent aging constitutive model in accurately predicting the mechanical property changes of EPDM rubber under different strain rates and aging states. The consistency between the experimental data and the calculated results is within the acceptable error range. It is worth noting that the stress in the model shows the dependence on strain rate, aging time and aging temperature, emphasizing the mechanical property changes of EPDM rubber at high temperatures and low strain rates simulated in the uniaxial tensile state.

Graphical Abstract

Tocotrienol is a subfamily of natural vitamin E with multiple biological activities, including antioxidants, antiproliferative, proapoptotic, antiangiogenic, and anti-inflammatory properties. Despite numerous biological activities, the application of tocotrienol is hampered by its poor solubility, resulting in low bioavailability, and in turn, limits its therapeutic effectivity. To address these limitations, the present study focuses on the development of tocotrienol nanoemulsion, followed by an in vitro anticancer evaluation of the formula. The tocotrienol nanoemulsion was prepared by a combination of high-speed homogenization with ultrasonication, using food-grade canola oil and Tween 80 as oil phases and surfactants, respectively. The formulated nanoemulsion observed an encapsulation efficiency of 90.26% with particle size and zeta potential of 145 ± 0.06 nm and −25.27 ± 0.01 mV, respectively. The FTIR spectra show no interference between the active compounds and the excipients, indicating that tocotrienol was successfully loaded into the nanoemulsion. Besides, the tocotrienol nanoemulsions demonstrated higher antioxidant ABTS (2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) radical scavenging activity than the free form of tocotrienol at the same concentration (p < 0.05). In the in vitro cytotoxicity studies, there was a decrease in cell viability observed against MCF-7 breast and A549 lung cancer cell lines for tocotrienol nanoemulsion. Overall, it suggests that nanoemulsion-based natural component delivery systems have substantial implications in developing and designing encapsulated biologically active systems. The potent cytotoxicity of tocotrienol-loaded nanoemulsion under aqueous phases provides insight into the development of nanoemulsion systems for enhancing the bioavailability and activity of tocotrienol as well as other lipophilic compounds in water systems, particularly for anticancer therapeutic.

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Polymer resin-based solid amine are prospective adsorbents used in removing CO₂ from biogas. Two commercial resins with different porous structures, AB-8 and ADS-17, were selected as supports to explore the influence of the support structures on adsorbent performance. It was discovered that macroporous channels greatly boost CO₂ adsorption at higher PEI loadings (≥ 30%), and their influence is more critical than total pore volume or specific surface area, though their impact is minimal at low PEI loadings. ADS-17-40% PEI demonstrated outstanding CO₂ adsorption of 208 mg·g⁻¹ in its 16th cycle under specific operating conditions. Increasing gas flow rate to 200 mL·min⁻¹ could promote CO₂ adsorption capacity and initial adsorption rate constant (k₀) calculated by the deactivation model. The highest adsorption capacity was achieved at 55 °C, when the temperature ranged from 25 to 90 °C.

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