Long Chain Structure Research Articles

Magnetic poly(phages) encoded probes-based dual-mode assay for rapid determination of live Escherichia coli and Hafnia paralvei based on microfluidic chip and ATP bioluminescence meter.

Adual-mode assay was developedfor screening and detecting live Escherichia coli (E. coli) and Hafnia paralvei (H. paralvei) (as two typical pathogens in aquatic environments) based on magnetic poly(phages) encoded probes (MPEP). The probes were prepared by grafting a large number of phages targeting different target bacteria on a long-chain DNA structure, respectively. They could specifically capture and enrich E. coli and H. paralvei by magnetic separation. Then, different DNA signal tags with different lengths conjugate with the corresponding MPEP-bacteria complex and form two kinds of sandwich structures, respectively. After that, the captured E. coli and H. paralvei were lysed to release both adenosine triphosphate (ATP) and DNA signal tags. The measurement includes two steps. Firstly, a portable ATP bioluminescence meter was employed to rapidly screen the positive samples that contain either of the two target bacteria. Secondly, only positive samples were injected into the microfluidic chip which could detect various DNA signal tags for accurate quantification of the target bacteria. The assay demonstrated high sensitivity (3 CFU/mL for E. coli and 5 CFU/mL for H. paralvei), high specificity (strain identification), signal amplification (20-fold), and short time (≤ 35 min). It can be applied to detect other pathogens solelyby changing the relative phage in MPEP. Furthermore, the proposed dual-mode assay provides a wide prospect for rapid screening and accurate determination of live foodborne pathogens. Clinical Trial Number: nbdxms-20240322.

Double network hydrogel confined MXene/Liquid metal by dynamic hydrogen bond for high-performance wearable sensors

Double-network (DN) hydrogels, which integrate long-chain and short-chain molecular structures, exhibit significant potential in wearable sensors due to their exemplary mechanical properties. However, conventional hydrogels often suffer from poor conductivity and low sensitivity. In this study, we develop a novel DN hydrogel (comprising polyacrylamide/sodium alginate) that encapsulates MXene (Ti3C2Tx) and liquid metal (LM). This configuration leverages the conductive properties of two-dimensional MXene and zero-dimensional liquid metal embedded within the DN hydrogel networks. The Ti3C2Tx MXene sheets enhance the binding capacity with LM by serving as a conductive bridge, thereby improving interfacial interactions and reducing hysteresis. The resultant strain sensor, fabricated from this composite DN hydrogel, achieves high sensitivity (gauge factor up to 12.84), a broad detection range (0 %-1500 %), rapid response time (262 ms), and excellent repeatability and stability. We have integrated this strain sensor into wearable flexible devices, such as contact lenses, enabling real-time monitoring of human physiological pressures.

Recovery of Selenium-Enriched Polysaccharides from Cardamine violifolia Residues: Comparison on Structure and Antioxidant Activity by Different Extraction Methods.

The residues from selenium-enriched Cardamine violifolia after the extraction of protein were still rich in polysaccharides. Thus, the recovery of selenium polysaccharides (SePSs) was compared using hot water extraction and ultrasonic-assisted extraction techniques. The yield, extraction rate, purity, specific energy consumption, and content of total and organic selenium from different SePS extracts were determined. The results indicated that at conditions of 250 W (ultrasonic power), 30 °C, and a liquid-to-material ratio of 30:1 extracted for 60 min, the yield of SePSs was 3.97 ± 0.07%, the extraction rate was 22.76 ± 0.40%, and the purity was 65.56 ± 0.35%, while the total and organic selenium content was 749.16 ± 6.91 mg/kg and 628.37 ± 5.93 mg/kg, respectively. Compared to traditional hot water extraction, ultrasonic-assisted extraction significantly improves efficiency, reduces energy use, and boosts both total and organic selenium content in the extract. Measurements of particle size, molecular weight, and monosaccharide composition, along with infrared and ultraviolet spectroscopy, revealed that ultrasonic-assisted extraction breaks down long-chain structures, decreases particle size, and changes monosaccharide composition in SePSs, leading to lower molecular weight and reduced dispersity. The unique structure of SePSs, which integrates selenium with polysaccharide groups, results in markedly improved antioxidant activity and reducing power, even at low concentrations, due to the synergistic effects of selenium and polysaccharides. This study establishes a basis for using SePSs in functional foods.

Effect of novel non-inhibitor slurry on chemical mechanical polishing properties of copper interconnect copper film based on experiments and theoretical calculations

In order to simplify the component of copper slurry during chemical mechanical polishing (CMP) and improve the surface corrosion inhibition efficiency, anionic surfactant dodecylbenzene sulfonic acid (DBSA) and nonionic surfactant decyl glucoside (DG) as mixed surfactants were used instead of inhibitors, and the corrosion inhibition properties were thoroughly studied by experiments and theoretical calculations. Polishing experiments and surface morphology tests show that the mixed surfactants can effectively enhance the surface quality after CMP compared with traditional inhibitor TAZ. Electrochemical experiments show that DG and DBSA can form a dense passivation film on the Cu surface to prevent corrosion. The inhibition efficiency of mixed surfactants is as high as 95 %. The theoretical calculations indicate that DBSA and DG form a stable long-chain structure, which leads to a higher adsorption energy, a denser passivation film, and stronger corrosion inhibition, in agreement with the experimental findings. These studies confirmed the stronger inhibitory effect of mixed surfactant on Cu film CMP and provided a new reference for the design of simplified slurry without inhibitor components.

Correlating color with free radical concentration in irradiated poly(ethylene terephthalate)

When polymers are irradiated, free radicals form, often accompanied by yellowing in the material. This color gradually fades after active irradiation due to the decay of free radicals. This study analyzed the kinetics of post-irradiated PET discoloration under different temperatures using a UV–visible spectrophotometer. Meanwhile, the free radical decay was also monitored using the electron paramagnetic resonance (EPR) measurements, and then both experiments were compared. The results illustrate the potential of readily available spectrophotometry as an alternative method to track free radical evolution in irradiated polymers because free radical decay leads to the disappearance of annealable color centers over time. Furthermore, PET structure modification by irradiation was studied using extensional rheological analysis. The observed strain hardening suggests the evolution of long-chain branching structures in post-irradiated PET, especially at 50 kGy irradiation absorbed dose.

FORMULATION AND EVALUATION COMBINATION OF CARBOPOL/HPMC POLYMER GELS CONTAINING OFLOXACIN FOR OCULAR DRUG DELIVERY SYSTEM

The current research focuses on assessing hydrochloride/HPMC polyethylene blends for uveitis drug delivery. Processes involving polypropylene (PP) matrices have shown similar behavior to solid lipid nanoparticles, with fluid sub-assemblies playing a larger role. Nanoemulsions, with long-chain structures, link drug dispersibility and rheology. The correct combination of polymer matrices is essential for designing an effective ocular drug delivery system.Further studies suggest that polypropylene enhances self-organization, while HPMC K100 improves drug dissolution and viscosity, particularly in formulations involving narcotics. A blend of three polymers has demonstrated effects on drug dissolution, dispersibility, and viscosity.Nanoemulsion-based formulations have shown the best results for drug dissolution and decent rheological properties. Cultured cell investigations indicate that higher levels of specific plastics improve dosage forms. Overall, this research emphasizes the importance of polymer selection and formulation in optimizing drug delivery for uveitis treatment.

Increasing softening point of isotropic spinnable asphalt by two-step preparation from ethylene tar residue modified with bio tar residue

Carbon fiber prepared from asphalt may be a critical type of low-weight chemical material of excellent mechanical performances. Here, an isotropic spinnable asphalt (EBA) was prepared from ethylene tar residue (ETR) by a two-step method of bio tar residue (BTR) through co-polymerization-air blowing, and isotropic asphalt carbon fibers were prepared from the product asphalt. The main types of molecules contained in the two feedstocks were determined by 1H NMR and LDI-TOF MS analyses. The co-polymerization behavior and thermal stability of the asphalt blends were analyzed using polarized light microscopy and thermogravimetric analyzer, respectively. Finally, the morphology and mechanical properties of carbon fibers made from EBA were evaluated by scanning electron microscope and universal testing machine. The results show that BTR contains much more oxygen-containing functional groups and unique long-chain sawtooth molecular structure; the former can promote the reactivity of the co-polymerization reaction, and the latter can limit the formation of large-plane cyclic aromatic hydrocarbon polymers due to the spatial resistance effect to greatly reduce the content of the mesophase. The softening point of the product asphalt shows a tendency of increasing and then decreasing with the increase of the proportion of BTR in the raw material mixture, and a reaction mechanism based on linear and bulky molecules is proposed to explain it by analogy with the structure of macromolecules. Consequently, the EBA made from a mixture of ETR and BTR at ideal moderate proportions has excellent performance in terms of softening point and mesophase content than ETRO made from ETR alone, and the carbon fiber made has a high tensile strength of 1.82 GPa with an elastic modulus of 38.9 GPa, which has reached the level of high tensile strength carbon fiber. Therefore, the use of inexpensive renewable energy bio-asphalt in the modification of heavy oil to obtain high softening point isotropic asphalt for preparing isotropic carbon fiber with excellent properties is achievable.

A strategy for tough and fatigue-resistant hydrogels via loose cross-linking and dense dehydration-induced entanglements

Outstanding overall mechanical properties are essential for the successful utilization of hydrogels in advanced applications such as human-machine interfaces and soft robotics. However, conventional hydrogels suffer from fracture toughness-stiffness conflict and fatigue threshold-stiffness conflict, limiting their applicability. Simultaneously enhancing the fracture toughness, fatigue threshold, and stiffness of hydrogels, especially within a homogeneous single network structure, has proven to be a formidable challenge. In this work, we overcome this challenge through the design of a loosely cross-linked hydrogel with slight dehydration. Experimental results reveal that the slightly-dehydrated, loosely cross-linked polyacrylamide hydrogel, with an original/current water content of 87%/70%, exhibits improved mechanical properties, which is primarily attributed to the synergy between the long-chain structure and the dense dehydration-induced entanglements. Importantly, the creation of these microstructures does not require intricate design or processing. This simple approach holds significant potential for hydrogel applications where excellent anti-fracture and fatigue-resistant properties are necessary.

Cocrystal of Lutein with Improved Stability and Bioavailability.

Lutein (LT) is a natural carotenoid and is widely used for its vision protection and antioxidant activity. However, the long-chain polyene structure makes lutein sensitive to light and oxygen and poses many difficulties in the production, processing, and storage. In addition, the special chemical structure of LT leads to low solubility and bioavailability. In this study, we propose an efficient solution to address these issues. A cocrystal of LT with adipic acid (LT-APC) was obtained for the first time. The cocrystals were fully characterized. After cocrystallization, the melting point of marketed LT was increased. The chemical stability of LT was significantly improved, and the influence of impurities on stability was limited. Dissolution experiments were performed in simulated gastric fluid (SGF) and simulated intestinal fluid (SIF) and the cocrystal generated a much higher apparent solubility. To deepen insight into the mechanisms underlying the cocrystal's improved solubility, wettability tests were performed by contact angle determination and film flotation methods. The cocrystal presented better wettability than the marketed LT. Finally, pharmacokinetic studies of marketed LT and its cocrystal were conducted in rats. The results showed that the cocrystal exhibited 3.4 times higher C max and 2.2 times higher AUC at a single dose compared with marketed LT.

Conversion of estriol to estrone: A bacterial strategy for the catabolism of estriol

Natural estrogens, including estrone (E1), 17β-estradiol (E2), and estriol (E3), are potentially carcinogenic pollutants commonly found in water and soil environments. Bacterial metabolic pathway of E2 has been studied; however, the catabolic products of E3 have not been discovered thus far. In this study, Novosphingobium sp. ES2-1 was used as the target strain to investigate its catabolic pathway of E3. The metabolites of E3 were identified by high performance liquid chromatography-high resolution mass spectrometry (HPLC-HRMS) combined with stable 13C3-labeling. Strain ES2-1 could almost completely degrade 20 mg∙L-1 of E3 within 72 h under the optimal conditions of 30°C and pH 7.0. When inoculated with strain ES2-1, E3 was initially converted to E1 and then to 4-hydroxyestrone (4-OH-E1), which was then cleaved to HIP (metabolite A6) via the 4, 5-seco pathway or cleaved to the B loop via the 9,10-seco pathway to produce metabolite with a long-chain ketone structure (metabolite B4). Although the ring-opening sequence of the above two metabolic pathways was different, the metabolism of E3 was achieved especially through continuous oxidation reactions. This study reveals that, E3 could be firstly converted to E1 and then to 4-OH-E1, and finally degraded into small molecule metabolites through two alternative pathways, thereby reducing E3 pollution in water and soil environments.

Correlation between synthesis parameters and hyperelasticity of hydrogels: Experimental investigation and theoretical modeling

The mechanical properties of hydrogels are significantly influenced by synthesis parameters. Although the mapping from the space of synthesis parameters to the space of properties has been investigated experimentally, a quantitative theoretical framework is still lacking. In this work, the effect of synthesis parameters on the hyperelastic behaviors of hydrogels was experimentally studied. Subsequently, we conducted theoretical analysis by combining the constitutive model and polymer physics to quantify the correlation between synthesis parameters (the initial water content, current water content, and degree of cross-linking) and hyperelasticity (the elastic modulus, degree of entanglement, and stress-stretch ratio curve) of hydrogels. The internal relation between critical polymer content for entanglement and both the initial water content and degree of cross-linking arises from the scaling laws. By analyzing the critical polymer content for entanglement and comparing it with the current polymer content, hydrogels are categorized as either cross-linking-dominated or entanglement-dominated. The current study indicates that a low degree of cross-linking, i.e., a long-chain structure, is an important prerequisite for plenty of entanglements. Hydrogels with low cross-linking are highly entangled, whether they possess high initial water content/low current water content or low initial water content/high current water content. This work paves the way for the systematic design of synthesis parameters, thereby guiding the modulation and optimization of the overall mechanical properties and the application of hydrogels.

MODIFICATION OF PINDIGA BENTONITE CLAY WITH DIDODECYLDIMETHYLAMMONIUM BROMIDES SURFACTANT FOR FOUNDRY USE

Bentonite clay from Pindiga, Gombe State, Nigeria, was surface modified with didodecyldimethylammonium bromides (DDAB) by the Base Exchange (cation exchange capacity) method for its possible use in foundries. The surfaces of the unmodified and modified Pindiga bentonite clay were characterised by means of spectroscopic, diffraction, and scanning methods (X-Ray fluorescence spectrometry (XRF)Fourier-transformed infrared spectroscopy (FTIR), X-ray diffraction (XRD), and scanning electron microscopy (SEM).XRF showed that unmodified sample was rich of montmorillonite (MMt) with ca +2 as exchangeable cation, FTIR analysis revealed that unmodified water absorption causes stretching and bending vibrations for hydroxyl groups, with the most intense bands in the low-frequency region, while DDAB organo-bentonites showed slight changes in wave bands, with a strong methyl band and a weak methyl band indicative of long-chain linear aliphatic structure. The basal spacing of the unmodified bentonite sample was 1.52 nm, and after modification with DDAB, it improved to 2.1 nm as determined from the X-ray diffraction (XRD) analysis. Results of the SEM images revealed rougher surfaces with uniformly dispersed small particles of grain-like structures characteristic of the unmodified, while theorgano-modified bentoniterevealed clusters of different sizes and shapes, larger Fe 3+ ions replacing smaller Al 3+ ions at octahedral sites, discontinuous layers enveloping large grains, polygonal growth foams with octahedral and tetrahedral shapes, mixed layers of calcium bentonite, and particle sizes less than 200nm. The study concluded that modified bentonite with didodecyldimethylammonium bromides gives good microstructure, increases rigidity, and improve thermal stability, to the organoclays. Therefore, it is recommended that DDAB bentonite be used as binder for foundries.

Efficient fluoride removal using nano MgO: mechanisms and performance evaluation.

In this study, highly efficient fluoride removal of nano MgO was successfully synthesized using a simple hydrothermal precipitation method. Hexadecyl trimethyl ammonium bromide (CTMAB) was utilized as a surfactant. Its long-chain structure tightly wrapped around the precursor crystal of basic magnesium chloride, inhibiting the growth of precursor crystals, reducing their size, and improving crystal dispersion. This process enhanced the adsorption capacity of nano MgO for fluoride. The adsorption performance of nano MgO on fluoride was investigated. The results indicate that pseudo-second-order kinetics and the Langmuir isotherm model can describe the adsorption behavior for fluoride, with a maximum adsorption capacity of 122.47mg/g. Methods such as XRD, SEM, XPS, and FTIR were employed to study the adsorption mechanisms of the adsorbent. Additionally, factors potentially affecting adsorption performance in practical applications, such as pH and competing ions, were examined. This study enhances our profound understanding of the defluorination effectiveness and mechanisms of nano MgO.

An ONIOM-Based High-Level Thermochemistry Study on Hydrogen Abstraction Reactions of Large Straight-Chain Alkanes by Hydrogen, Hydroxyl, and Hydroperoxyl Radicals

Accurate thermochemical data are of great importance in developing quantitatively predictive reaction mechanisms for transportation fuels, such as diesel and jet fuels, which are primarily composed of large hydrocarbon molecules, especially large straight-chain alkanes containing more than 10 carbon atoms. This paper presents an ONIOM[QCISD(T)/CBS:DFT]-based theoretical thermochemistry study on the hydrogen abstraction reactions of straight-chain alkanes, n-CnH2n+2, (n = 1–16) by hydrogen (H), hydroxyl (OH), and hydroperoxyl (HO2) radicals. These reactions, with n ≥ 10, pose significant computational challenges for prevalent high-level ab initio methods. However, they are effectively addressed using the ONIOM-based method. One notable aspect of this study is the consideration of the high symmetry of straight-chain alkanes. This symmetry allows us to study half of the reactions, employing a generalized approach. Therefore, a total of 216 reactions are systematically studied for the three reaction systems. Our results align very well with those from the widely accepted high-level QCISD(T)/CBS method, with discrepancies between the two generally less than 0.10 kcal/mol. Furthermore, we compared large straight-chain alkanes (n-C16H34 and n-C18H38) with large methyl ester molecules (C15H31COOCH3 and C17H33COOCH3) to elucidate the impact of functional groups (ester group and C=C double bond) on the reactivity of the long-chain structure. These findings underscore the accuracy and efficiency of the ONIOM-based method in computational thermochemistry, particularly for large straight-chain hydrocarbons in transportation fuels.

Optimizing the development and field application of calcium stabilizing agents for preventing calcium leaching in tunnels

As a hidden engineering structure, tunnels are inevitably affected by the long-term erosion of groundwater, resulting in the phenomenon of calcium leaching in shotcrete. The effective components of the initial tunnel support are dissolved by groundwater, with a portion remaining in the tunnel drainage system and the rest discharged from the tunnel. This phenomenon can further accelerate the deterioration of the lining and cause blockages in the drainage system, posing new challenges to environmental protection and structural safety. To mitigate the problem of calcium leaching in tunnel shotcrete, new building materials, termed Calcium Stabilizing Agents (CSAs), were fabricated using industrial solid wasters such as silica fume, mineral powder, silicone zirconium, and metakaolin. An orthogonal experiment was implemented to investigate the influence of CSAs on the calcium ion (Ca2+) leaching concentration; the sensitivity analysis was conducted to identify the impact of each ingredient of CSAs on the calcium ion leaching concentration; and microscopic methods such as XRD, SEM, and TG were used to analyze the mechanism of the CSAs on anti-calcium leaching ability of mortar. The results showed that the addition of the CSAs can effectively improve the anti-calcium leaching ability of mortar. For the optimal dosage of the CSAs mortar, the calcium ion concentration of the 28-day CSAs mortar was reduced by 31.55 %, and the compressive strength and flexural strength were enhanced 31.09 % and 37.27 %, respectively. From the sensitivity analysis of calcium ion concentration, compressive strength, and flexural strength of CSAs mortar at 1 day, 7 days, and 28 days, silica fume and zirconium silicone show the greatest influence on the performance of mortar. Consequently, they are deemed as the core components of CSAs. The microscopic analysis showed that the internal cementitious structure of the cement stone grew denser after CSA was added. It also contained long-chain crystalline structures that effectively fill capillary pores to resist erosion. Finally, the CSAs product was applied to a tunnel under construction on site, and the results showed that the shotcrete mixed with CSAs had a good anti-calcium leaching effect and significantly improved compressive strength. The findings of this study can provide a new avenue for preventing and controling the tunnel crystallization diseases.

Preparation and Characterization of Guaiacol-Furfuramine Benzoxazine and Its Modification of Bisphenol A-Aniline Oxazine Resin.

A new type of benzoxazine resin has been synthesized using a natural phenol source, guaiacol, and a biomass amines, furfuramine. The synthesis conditions were optimized; when the reaction molar ratio of guaiacol, furfuramine, and polyformaldehyde was 1:1:4, the highest synthetic yield was reached. The product was characterized via testing using transform infrared spectroscopy (FT-IR), gel permeation chromatography (GPC), mass spectrogram (MS), and nuclear magnetic resonance (1H-NMR) to confirm its molecular structure. A differential scanning calorimetry (DSC) test was conducted to analyze the thermodynamic properties of the product, and the results showed that the product decomposed and evaporated at around 180 °C, making it impossible to achieve self-curing. However, the prepared guaiacol-furfuramine benzoxazine resin (GFZ) can be blended and cured in certain proportions with bisphenol A-aniline oxazine resin (BAZ) as a GFZ/BAZ binary system (5:95, 10:90, 20:80, and 40:60). Dynamic mechanical analysis (DMA) test results showed that when the content of GFZ was 10%, the storage modulus of the copolymer resin was greatly improved. After conducting impact strength tests on the copolymer resin, it was found that the toughness of the copolymer resin had improved, and the maximum impact strength had increased by nearly three times. This indicates that the flexible long-chain structure in GFZ can effectively improve the toughness of the cured copolymer system. The reaction of active groups on benzoxazine molecules with other resins can not only improve the mechanical properties of their cured products, but also has important significance in the preparation of low-cost and environmentally friendly sustainable composite materials with excellent comprehensive performance.

Bionic structure and biocompatibilities of long chain branched poly(L-lactic acid) oriented microcellular foaming material

In order to solve the problem of uneven microporous structure of Poly(L-lactic acid) (PLLA) bulk orientation by using biological safety multi-functional plant oil as chain extenders (CE), multi-armed flexible chains were introduced into PLLA through reactive processing to prepare long chain branched PLLA (LCB-PLLA). When the total content of the CE was 6.15 wt%, PLLA and the CE reacted most fully, while maintaining the tensile strength of PLLA and improving toughness. After introducing the LCB structure, the presence of multi-armed flexible chains increased the mobility of the molecular chains, resulting in a significantly lower degree of crystallinity. When the draw ratio up to 900 %, the crystallinity of LCB-PLLA-F-900 % was only 45.15 %, lower than that of PLLA-F-900 %. Thanks to the mobility of polymer chains can be enhanced, which reduces the degree of crystallinity while promoting the uniform growth of oriented microporous structures. Finally, an oriented micro-porous biomimetic LCB-PLLA material with an average cell diameter of 540 nm was prepared, and the results of in vitro cell culture showed that the oriented micro-porous LCB-PLLA biomimetic material was more conducive to cell proliferation.

Adaptive responses and metabolic strategies of Novosphingobium sp. ES2-1–17β-estradiol analyzed through integration of genomic and proteomic approaches

Environmental 17β-estradiol (E2) can cause potential harm to ecological balance and human health. Novosphingobium sp. ES2–1 is an E2-degrading bacterium previously obtained, which converts E2 to estrone (E1) and then to 4-hydroxyestrone (4-OH-E1) followed by oxidation to form metabolites with long-chain structure during upstream degradation. Herein, we found that intracellular enzymes were the major contributors to E2 biodegradation by strain ES2–1. A total of 243 proteins were dys-expressed under E2 condition, 123 were up-regulated and 120 were down-regulated thereinto. The up-regulated members of ABC transport systems, aromatics degradation, and fatty acid degradation indicated a reinforced transfer and utilization of E2. Cytochrome P450 monooxygenase (EstP1), 2-keto-4-pentenoate hydratase, pyruvate dehydrogenase, acetyl-CoA acetyltransferase, TonB-dependent receptor were involved in E2 catabolism. During downstream degradation, the metabolites with long-chain structure were decomposed adopting β-oxidation pattern and ultimately entered the TCA cycle; 2-keto-4-pentenoic acid might be an emblematic product of such process. Furthermore, E2 converting to E1 was catalyzed by 17β-dehydrogenase probably encoded by IM701_16645 or IM701_16910; 4-OH-E1 meta-cleavage was catalyzed by a dioxygenase encoded by IM701_20340 or IM701_21000 or IM701_09625. Our study provided an in-depth insight into the adaptive responses and metabolic strategies of Novosphingobium to E2.

Effects of Stearic Acid and Zein Incorporation on Refined Kappa Carrageenan-Based Composite Edible Film Properties

Incorporating hydrophobic materials into a polysaccharide-based film to form a composite edible film has been considered an effective way to strengthen the film properties, especially the water vapor resistance. Fatty acids, such as stearic acid, with long-chain and straight structures, exhibit strong hydrophobic performance to prevent water vapor diffusion through the film surface. Meanwhile, zein has been revealed as an encouraging material due to its compactness, less allergic, and gas barrier properties. The investigation of kappa-carrageenan/zein/stearic acid-based green composite edible film has been limited. Thus, this study aims to examine the effect of increasing stearic acid and zein concentrations on improving the moisture barrier and mechanical properties of kappa carrageenan-based composite edible film. Different concentrations of stearic acid (5, 10, and 15% w/w carrageenan) and zein (2.5, 5, and 7.5% w/w carrageenan) were applied to the composite edible film prepared using the solution casting method. The fabricated films have a thickness of 0.092–0.122 mm. The results indicated that increasing the concentration of stearic acid enhances the water vapor barrier and tensile strength of the edible film (p < 0.05). However, the increased zein concentration slightly weakened the water vapor barrier properties. Then, the elongation of the manufactured films was quite improved by the increment of stearic acid proportion, but neither by the increment of zein proportion nor the combination of these two substances. However, the incorporation of stearic acid and zein into refined-kappa carrageenan-based film remarkably improved the tensile strength, elongation, and water vapor barrier properties by 12–18%, 23–27%, and 43–44%, respectively, in comparison to the neat film. Based on the analysis result, the manufactured film which consists of 10% stearic acid and 2.5% zein is considered as the best film formula. This study, therefore, revealed the potentiality of stearic acid enforcement in food packaging applications.

High contrast ratio and fast response ferroelectric liquid crystal displays based on alignment optimization

There are a series of polyimide material synthesized and studied with different dianhydride and diamine structures. By exploring the structural variations of these materials and their surface energy characteristics, we successfully obtained ferroelectric liquid crystal devices exhibiting exceptional optical and electrical properties. Notably, our findings highlight that a specific polyimide material comprised of dianhydride with a benzene ring structure and diamine with a long-chain amino structure demonstrates remarkable achievements, including a maximum contrast of 872 and a rapid response speed of less than 0.1 ms. These results establish the superiority of this particular polyimide material over its commercially available counterparts. Additionally, the optical characteristics of various polyimide materials were examined by establishing a correlation between these properties and the surface energy of the materials. This research presents a novel approach to developing alignment materials suitable for ferroelectric liquid crystal applications. The implications of our findings are of great significance in driving advancements in field-sequential-color display devices with high pixels per inch in the ferroelectric liquid crystal field.