Stearic Acid Content Research Articles

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.

Preparation and performance of self‐healing nanocomposite coating with hydrophobic self‐cleaning ability

AbstractWith the rapid development of today's society, hydrophobic materials are widely used in many fields due to their excellent hydrophobicity. This article presents a nanocomposite coating with self‐cleaning and self‐healing properties. The nanoparticles (TiO2) were prepared by hydrothermal method, and the TiO2 was hydrophobically modified by adjusting the content of stearic acid (SA) and compounded with a synthetic self‐healing silicone‐containing polyurethane (SiPU). A self‐healing nanocomposite coating (SA‐TiO2/SiPU) with hydrophobic self‐cleaning capability was obtained by a simple brushing technique, with a water contact angle of up to 135.1° and good mechanical properties, reaching a maximum tensile strength of 3.11 MPa and a maximum elongation of 537%, and a repair efficiency of 89.39% after 12 h of fracture repair at room temperature. The self‐healing properties and stability of the coating can increase the service life of the coating, and the self‐cleaning properties can also effectively prevent contaminants from adhering to the surface; its excellent performance has the potential for a wide range of practical applications.Highlights An environmentally self‐cleaning composite coating (SA‐TiO2/SiPU) was prepared in this study. The preparation method of the hydrophobic composite coating is simple. The micro‐nano structure of SA‐TiO2/SiPU is critical for its hydrophobicity. The SA‐TiO2/SiPU coating with good self‐healing properties. The SA‐TiO2/SiPU exhibited excellent durability and self‐cleaning properties.

The development of balqymyz beverage from honey and koumiss

The relevance of this research lies in the development of a health-safe beverage, balqymyz, made from honey and koumiss, which exhibits improved taste properties, increased content of beneficial fatty acids and amino acids, and extended shelf life, making it a natural, easy-to-produce, and high-quality beverage with potential health benefits. The study aims to develop a health–safe beverage from honey and koumiss – balqymyz. A total of 75 samples were analyzed, including organoleptic, physicochemical, and taste properties, with three different concentrations of honey. The water content in the beverage, depending on the honey concentration (5%, 7.5%, 10%), ranged from 85% to 90%. No deviations from the maximum permissible levels of radionuclides were observed (Table 1); for example, the concentration of strontium in dairy products is considered normal at 2.5 mg per 1 kg. A significantly higher alcohol content was found in the beverage with a 10% honey concentration compared to the 5% samples (p ≤ 0.05). The proposed production method increased the mean content (in % of total fat content) of oleic, linoleic, ʏ-linolenic and arachidonic acids from 13.589 ± 1.359, 6.531 ± 0.653, 0.158 ± 0.016 and 0.470 ± 0.047% to 14.674 ± 1.467, 6.228 ± 0.623, 0.169 ± 0.017 and 0.729 ± 0.073%, respectively. The content of stearic acid increased to 2.852 ± 0.285%. Other improvements occurred in the amino acid content of glutamic acid (8%), leucine (5%), lysine (4%), and tryptophan (4%). These improvements enhance the sensory characteristics of the beverage and lead to shelf life prolongation by more than 72 h. Other advantages of balqymyz are naturalness, ease of production and high quality of ingredients.

Enhanced performance and stability of Cu/ZnO catalyst by hydrophobic treatment for low-temperature methanol synthesis from CO2

CO2 hydrogenation to methanol is an efficient way to utilize CO2 and store hydrogen. However, realizing high activity and methanol selectivity as well as excellent stability are still challenges due to the competitive reverse water-gas shift (RWGS) reaction and the accumulation of water on the catalyst surface. Herein, Cu/ZnO catalyst was prepared by oxalic acid-assisted solid-state grinding method and then was subjected to hydrophobic treatment using stearic acid as a functionalization agent. The effect of stearic acid concentration on the physicochemical properties of Cu/ZnO catalysts and the catalytic activity for low-temperature CO2 hydrogenation to methanol was investigated and discussed in detail. Detailed catalyst characterizations disclosed that hydrophobic treatment using suitable concentration of stearic acid removed residues from the decomposition of oxalic acid and also increased specific surface area, surface basicity, reducibility and hydrogen adsorption strength on Cu/ZnO catalysts, leading to the enhanced catalytic performance and methanol selectivity. Among all the catalysts, Cu/Zn-2 mM catalyst exhibited methanol selectivity and methanol space time yield (STY) of 78.8% and 87.17 g/kg·h−1 at 200 ℃, much higher than those of untreated Cu/ZnO catalyst (71.7% and 68.93 g/kg·h−1). The hydrophobic Cu/Zn-2 mM catalyst also exhibited outstanding stability for low-temperature CO2 hydrogenation to methanol, keeping its activity for 100 h without obvious deactivation when compared to untreated Cu/ZnO catalyst. This facile hydrophobic treatment using stearic acid not also enhanced catalytic activity, methanol selectivity and stability of Cu/ZnO catalysts for low-temperature methanol synthesis, but also enlightened the invention of more hydrophobic materials in the near future.

A novel type of Brassica napus with higher stearic acid in seeds developed through genome editing of BnaSAD2 family.

Modifications of multiple copies of the BnaSAD2 gene family with genomic editing technology result in higher stearic acid content in the seed of polyploidy rapeseed. Solid fats from vegetable oils are widely used in food processing industry. Accumulating data showed that stearic acid is more favorite as the major composite among the saturate fatty acids in solid fats in considerations of its effects on human health. Rapeseed is the third largest oil crop worldwide, and has potential to be manipulated to produce higher saturated fatty acids as raw materials of solid fats. Toward that end, we identified four SAD2 gene family members in B. napus genome and established spatiotemporal expression pattern of the BnaSAD2 members. Genomic editing technology was applied to mutate all the copies of BnaSAD2 in this allopolyploid species and mutants at multiple alleles were generated and characterized to understand the effect of each BnaSAD2 member on blocking desaturation of stearic acid. Mutations occurred at BnaSAD2.A3 resulted in more dramatic changes of fatty acid profile than ones on BnaSAD2.C3, BnaSAD2.A5 and BnaSAD2.C4. The content of stearic acid in mutant seeds with single locus increased dramatically with a range of 3.1-8.2%. Furthermore, combination of different mutated alleles of BnaSAD2 resulted in more dramatic changes in fatty acid profiles and the double mutant at BnaSAD2.A3 and BnaSAD2.C3 showed the most dramatic phenotypic changes compared with its single mutants and other double mutants, leading to 11.1% of stearic acid in the seeds. Our results demonstrated that the members of BnaSAD2 have differentiated in their efficacy as a Δ9-Stearoyl-ACP-Desaturase and provided valuable rapeseed germplasm for breeding high stearic rapeseed oil.

Fatty acid profile and rheological properties of cocoa paste from north-eastern Peru

This study evaluated the fatty acid profile and the physicochemical and rheological properties of cocoa mass obtained from twenty cacao accessions from the department of Amazonas, Peru. Eight types of fatty acids were identified: four saturated (palmitic, margaric, stearic and arachidic) and 4 unsaturated (palmitoleic, oleic, linoleic, α-linolenic). The INDES-37 accession had the highest percentage of fat in dried beans with 55.25%, while INDES-53 had the highest fat content in mass with 70.57%. Accession INDES-53 had higher linoleic acid content, CAP-92 had higher palmitic acid content, CAP-125 had higher stearic and arachidic acid abundance, and TSH-565 had higher oleic acid content. The cocoa mass from accession CAP-74 had higher viscosity (4.6 Pa·s), and those obtained from INDES-37 and CAP-125 had higher yield strength (17.36 and 19.64 Pa respectively). Cocoa mass hardness also varied according to the accession (from 1 099–8 829 g in TSH-565 and CAP-39, respectively). Palmitic acid content was negatively correlated to oleic, stearic, and linoleic acid content. Positive correlations were also observed between α-linolenic acid and cocoa mass hardness, and viscosity was positively correlated with arachidic acid. Cacao grown in Amazonas, Peru, has a diverse range of physicochemical and rheological characteristics that can be exploited for chocolate industrialization.

Ultra-deformable free fatty acid based nano-carriers for topical delivery of Luteolin: A potential paradigm for management of Methicillin-Resistant Staphylococcus aureus skin infections

The incidences of antimicrobial resistance in particular, Methicillin-Resistant Staphylococcus aureus (MRSA) have increased during the last two decades. However, conventional dosage forms are unable to evade the barrier effect of the stratum corneum to permit deep penetration of the skin to resolve deep skin infections. There is, therefore, an urgent need for an advanced drug delivery system. Thus the study reported herein was aimed to fabricate a novasome-loaded luteolin (LUT) to improve its topical delivery and to enhance its antibacterial activity. The system was investigated for the impact of the type of surfactant, stearic acid concentration (g %), cholesterol amount (mg) and Brij 52 amount (mg) on the percent entrapment efficiency, particle size, poly-dispersity index and zeta potential. Statistical optimization of these factors was conducted using the Design-Expert® software. The optimum formulation was further in-vitro characterized by release study, differential scanning calorimetry, transmission electron microscope, x-ray diffraction and antibacterial activity. Formulation F2 composed of Span 60, 0.4 g % of stearic acid, 100 mg cholesterol and 30 mg Brij 52 was selected as the optimum formula based on the highest desirability value (0.634). F2 demonstrated enhanced antimicrobial activity with lower minimum inhibitory concentrations against a panel of MRSA clinical isolates when compared to LUT dispersion. Furthermore, the F2 formula exhibited higher anti-virulence activity by effectively inhibiting biofilm formation and suppressing α-hemolysin activity in MRSA isolates. It also demonstrated improved biosafety based on cytotoxicity assessment on human skin fibroblasts (HSF). Finally, when assessed in an in vivo skin infection mouse model, the F2 formula and commercially available fusidic acid preparation significantly reduced the microbial load of infected skin lesions compared to both the negative control and LUT dispersion-treated groups. Based on the aforementioned results, the validity of novasomes as a nano-carrier to boost in vitro and in vivo anti-MRSA activity of LUT could be affirmed.

W/O/W type lotion formulation of “arum manis” mango (Mangifera indica L.) pell as antioxidant

Arum manis mango peel contains compounds, namely flavonoids. Flavonoid compounds act as natural antioxidants. The weakness of flavonoid compounds is that they are not stable to the influence of high temperature and light intensity, so that the arum manis mango peel extract is made in the form of lotion type W/O/W. This study aims to determine the physical characteristics and stability of the W/O/W type emulsion form optimum formula in double emulsion preparations and lotion preparations, determine the stability of W/O/W type lotion preparations during storage using the cycling test method and determine the IC50 value in the optimum formula. lotion preparation type W/O/W. The optimum formula for double emulsion type W/O/W is found in formula 5 with a ratio of primary emulsion: secondary emulsion (80%:20%) with span 80 (10%) and tween 20 (5%) concentrations while the optimum formula for lotion preparations found in formula 3 with a ratio of double emulsion type W/O/W: lotion base (80%:20%) with a concentration of stearic acid (5%), cetyl alcohol (2.5%) and glycerin (10%). In the antioxidant activity of lotion preparations, the IC50 value was 136.543 ppm and the stability test on the cycling test method had an unstable form.

Exploring the nutritional composition of cultured horseshoe crab (Tachypleus gigas): A study of proximate composition, minerals, amino acids, and fatty acids

This study was done to determine the proximate composition, mineral content, amino acid and fatty acid composition of Tachypleus gigas. T. gigas were collected at the Horseshoe Crab Hatchery and Breeding Centre, Malaysia. The samples were analyzed for its proximate composition of different body parts, roe and muscle. The mineral analysis was determined using Inductively Coupled Plasma mass spectrometer. The amino acids were analysed using High-Performance Liquid Chromatography and the fatty acids were analysed using Gas Chromatography-Flame Ionization Detector. The results showed that the roe of T. gigas contained higher crude proteins, crude fats and carbohydrates compared with muscle. Minerals content (K, Ca, and Na) were the most abundant in roe samples. The roe samples had higher concentrations of amino acids compared to the muscle samples, with the highest being 7.20 ± 0.66 g/100 g of leucine. The fatty acid composition showed that roe samples had higher concentrations of palmitic acid, stearic acid and oleic acid, contributing 21.0 ± 1.05%, 19.5 ± 1.60% and 32.4 ± 1.8%, respectively. These nutrients are important for human health and could help address nutrient malnutrition.

Optimization preparation and durability analysis of abrasion resistant-superhydrophobic cementitious material

In this study, stearic acid (SA), polymehtylhydrosiloxane (PHMS) and attapulgite (ATP) were mechanically mixed in absolute ethanol firstly. After that the mixture was coating on the surface of cementitious material to prepare abrasion resistant-superhydrophobic cementitious material. Through experiments and theoretical analyses, the effects of different coating methods and SA content on superhydrophobic and abrasion resistant properties were studied. Moreover, the impermeability and erosion resistance of abrasion resistant-superhydrophobic cementitious material under different working conditions were also investigated. The results indicate that coating method has a great influence on superhydrophobic properties. Compared with dip coating method, the material prepared by one-step spraying method has better superhydrophobic performance. The results also show that the reasonable addition of SA could significantly improve abrasion resistant of the material. In addition, the study indicates that with the increase of roughness, the surface energy of abrasion resistant-superhydrophobic cementitious material dramatically decreases. The surface energy of coating containing 2 wt% ATP is only 26.84% of the coating without any ATP. Furthermore, permeability and electrochemical experiments show that the abrasion resistant-superhydrophobic cementitious material prepared by one-step spraying method has excellent impermeability and erosion resistance.

Genetic analysis of sunflower fatty acids under optimum and water stressed conditions

Abstract In order to study the genetic control of sunflower fatty acids under optimum and water limited conditions a set of 12 sunflower hybrids were evaluated as randomized complete block design with three replications in two separate experiments during two years (2019 and 2020) in Karaj, Iran. The hybrids were obtained by crossing of four male sterile lines and three restorer lines as testers. Water limitation was imposed by water withholding during reproductive stage. Palmitic acid content was governed by both additive and non-additive effects and linoleic acid content by non-additive gene action under optimum and water limited conditions. Stearic acid content was controlled by both additive and non-additive effects in optimum but by additive effects under water limited condition. Oleic acid content was governed by non-additive factors in optimum, while by both additive and non-additive effects in water limited condition. Oil content and leaf temperature were inherited by additive and seed yield by additive and non-additive effects in both conditions. Relative water content and chlorophyll content were controlled by both additive and non-additive effects under optimum but by non-additive effects in water limited condition. According to these results hybrid breeding is suggested for improvement of main sunflower fatty acids under optimum and water limited condition except that selection-based methods for improvement of stearic acid content.

Fatty acid composition of cow milk when activated zeolite and probiotics are included in their diet

Relevance. The biosynthesis of milk fat is influenced by a large number of factors, including the feeding habits of animals.Methods. Milk samples were taken and prepared for analysis according to GOST 26809.1-2014. The fatty acid composition of the fatty phase of milk was determined by gas chromatography in accordance with GOST 32915-2014 on a gas chromatograph «Crystallux 4000M», capillary column SP2560.Results. Significantly the lowest content of stearic acid was observed in individuals of the second group — 11.362% (p ˂ 0.05). Animals of the second group had a significantly higher mass fraction of monounsaturated fatty acids: decenoic, myristooleic and palmitooleic — by 0.062% (p ˂ 0.05), and in terms of the content of myristooleic and palmitooleic acids — by 0.242% (p ˂ 0.05) and 0.159% (p ˂ 0.05), respectively. In animals of the second group, the content of polyunsaturated linoleic acid compared with the control was significantly lower by 0.385% (p ≥ 0.05). In general, it should be noted that the established mass fraction of stearic acid in the milk fat of animals of the third group was slightly higher, and palmitooleic acid in the milk of cows of all groups was slightly lower than the reference values provided for by GOST 32915-2014. The ratio of fatty acid methyl esters of milk fat in individuals of all groups corresponded to the permissible range of values according to GOST 32261-2013.

Ferulic acid treatment enhances the synthesis, transport and deposition of suberin polyaliphatic monomers on potato tuber wounds

Wound healing is a typical feature of harvested potato tubers, which can effectively inhibit pathogen infection, reduce water loss and extend the storage life of potato tubers. Ferulic acid (FA) is an essential phenolic acid in plants. Although some reports indicated that FA could improve plants resistance to biotic and abiotic stresses, however, there is no information on whether FA affects the synthesis, transport and deposition of suberin polyaliphatic (SPA) monomers on wounds of potato tuber during healing. In the present research, FA increased the contents of palmitic acid, stearic acid and oleic acid at wounds. FA also upregulated the expression of StLACS, StKCS, StFAR and StGPAT, and enhanced the levels of C20-C24 very long-chain fatty acids, C16-C22 ω-hydroxy acids, α,ω-diacids, primary alcohols and glycerides. Meanwhile, FA upregulated the expression of StFHT and StABCG, and increased ferulate content. In addition, FA promoted the deposition of SPA on the tuber wounds. Taken together, FA could accelerate the deposition of SPA on tuber wounds by stimulating the synthesis, cross-linking and transport of SPA monomers.

Mineral Content and Phytochemical Composition of Avocado var. Hass Grown Using Sustainable Agriculture Practices in Ecuador.

Avocado demand has increased in recent years due to the nutraceutical properties that this fruit has and its positive impacts on human health; however, avocado production also requires sustainable alternatives to improve its cultivation. The objective of this study was to carry out characterization of the mineral content and phytochemical compounds in avocado fruit of the Hass variety grown using sustainable agricultural practices in Ecuador. Our results show an increase in fruit quality traits, such as firmness, and in the content of soluble solids, protein, fiber, fat, carotenoids, Ca, Mg, Zn and stearic acid in the pulp of the avocado Hass variety, as well as an initial trend of yield increase with the application of sustainable practices. Moreover, antioxidant activity was associated with polyphenol content. There were positive correlations of Mg with K and Ca, and of flavonoids with linolelaidic, linoleic and linolenic acids. Overall, our results indicate that avocado can be used as a functional and nutritional food due to its phytochemical composition and the mineral content of its pulp, which contributes to the promotion of its consumption and encourages healthy eating. In addition, the use of sustainable practices, such as fertigation and the application of microorganisms, is also promoted for growing avocado.

Substitution of Pork Fat with Beeswax-Structured Oleogels in Semi-Smoked Sausages

The expansion of the assortment of low-saturated-fat sausages is a trend in healthy eating, and the use of alternative ways to reduce their saturated fat content is required. This study aimed to partially substitute pork fat with 7% and 10% oleogel, obtained by structuring sunflower oil with a two-component mixture of monoglyceride and beeswax, in the recipe for semi-smoked sausage. The physicochemical characteristics of the sausages were evaluated, and the fatty acid profile and sensory properties were analyzed. In the samples where pork fat was partially replaced with oleogel at 7% and 10%, there was a decrease in the content of saturated fatty acids (SFA) by 35% and 38%, respectively. The addition of oleogel to sausages significantly reduced the content of stearic and palmitic acid, increased the content of linoleic acid, and improved the fatty acid profile. The microstructure of the sausages showed a more homogeneous structure with a lower content of large lipid granules as the amount of oleogel added increased. The sensory analysis showed that the addition of 7% oleogel did not deteriorate the organoleptic properties. Therefore, the partial substitution of pork fat with 7% oleogel can be recommended to produce healthy sausages with improved fatty acid profile and sensory properties.

Fatty Acid, Carotenoid and Fat-Soluble Vitamin Composition of Multispecies Swards Grown in Ireland—Implications for a Sustainable Feed in Dairy Farming

Although traditional ryegrass pastures are still commonly used, they require intense management and input and do not perform well during the summer months. Multispecies systems have been recognised as more sustainable, needing less fertiliser and being tolerant to drought and heat. While data on monoculture system fat composition exist, information for multispecies is scarce. The present study compared the fatty acid (FA), carotenoid and fat-soluble composition of a multispecies system (consisting of perennial ryegrass, timothy, white clover, red clover, chicory and plantain) (MULTI) with two other conventional grazing systems (monoculture perennial ryegrass (PRG) and a binary mixture of perennial ryegrass and white clover (PRG+WC)) over the Irish late-summer grazing season of dairy cattle (July–September). The results showed that the three systems had similar levels of FAs (p > 0.05), with mean α-linolenic acid values of 20.00 mg/g in PRG, 18.51 mg/g in PRG+WC, and 17.90 mg/g in MULTI and mean linoleic acid values of 3.84 mg/g in PRG, 4.16 mg/g in PRG+WC, and 4.39 mg/g in MULTI. Fourfold and twofold increases in the concentrations of α-linolenic acid and linoleic acid, respectively, were observed throughout July–September. Variations in stearic acid concentrations were not significant (p > 0.05), and palmitic acid concentrations increased over time (p < 0.05). The average values of lutein (36.68 mg/kg in PRG, 31.26 mg/kg in PRG+WC, and 35.75 mg/kg in MULTI) and α-tocopherol (2.28 mg/kg in PRG, 1.49 mg/kg in PRG+WC, and 1.83 mg/kg in MULTI) were similar among the grazing systems (p > 0.05), and the average β-carotene value was 25% higher in monoculture ryegrass (140.74 mg/kg) than in the multispecies (102.51 mg/kg) (p < 0.05). Nonetheless, the levels of β-carotene found in the multispecies were still above the recommended intake required for ruminants. In conclusion, multispecies pastures could be included in dairy cattle production systems as a sustainable alternative to traditional pastures while also providing typically adequate sources of fats for animal diets.

Preparation and evaluation of ciprofloxacin solid dispersion tablets developed from stearic acid, Polyethylene Glycol 4000 and Soluplus

Ciprofloxacin is a fluoroquinolone antibiotic with a broad spectrum of activity used for the treatment of various bacterial infections and is characterized by poor aqueous solubility and low permeability. The aim of this study is to formulate and characterize ciprofloxacin solid dispersions using hydrophilic and lipophilic matrices for improved product qualities and drug delivery. Ciprofloxacin hydrochloride tablets were formulated as solid dispersions by melting and solvent evaporation in tablet moulds using varying concentrations of stearic acid (10-40 %w/w), Polyethylene glycol 4000 (PEG 4000) (10-40 %w/w) and Soluplus® (10-20 %w/w as ethanolic solution) as components. The prepared tablets were evaluated for weight uniformity, friability, hardness, Fourier transform-infrared spectroscopy (FT-IR), moisture uptake, swelling index, disintegration time and dissolution rate, using standard methods and optimization techniques. The results showed uniform solid dispersion weights with friability, hardness, moisture uptake and swelling index of 0.4-0.5%, 3.0-7.5 kgf, mostly <20% and 1-71%, respectively. The formulations were chemically stable with no transformational interactions between components. Formulations without stearic acid disintegrated within 30 min whereas those containing the lipid broke up after more than 1 h. Drug release studies showed high immediate release in tablets without stearic acid but with cumulative steady state release higher in formulations with 10 %w/w Soluplus and different concentrations of stearic acid and PEG 4000. In conclusion, ciprofloxacin was presented as solid dispersion tablets with modified physicochemical attributes for improved drug delivery.
 Keywords: Ciprofloxacin; solid dispersion; drug delivery

Significant Improvement of Thermal Conductivity of Polyamide 6/Boron Nitride Composites by Adding a Small Amount of Stearic Acid.

This study investigates the effect of adding stearic acid (SA) on the thermal conductivity of polyamide 6 (PA6)/boron nitride (BN) composites. The composites were prepared by melt blending, and the mass ratio of PA6 to BN was fixed at 50:50. The results show that when the SA content is less than 5 phr, some SA is distributed at the interface between BN sheets and PA6, which improves the interface adhesion of the two phases. This improves the force transfer from the matrix to BN sheets, promoting the exfoliation and dispersion of BN sheets. However, when the SA content was greater than 5 phr, SA tends to aggregate and form separate domains rather than being dispersed at the interface between PA6 and BN. Additionally, the well-dispersed BN sheets act as a heterogeneous nucleation agent, significantly improving the crystallinity of the PA6 matrix. The combination of good interface adhesion, excellent orientation, and high crystallinity of the matrix leads to efficient phonon propagation, resulting in a significant improvement in the thermal conductivity of the composite. The highest thermal conductivity of the composite is achieved when the SA content is 5 phr, which is 3.59 W m-1 K-1. The utilization of a composite material consisting of 5phr SA as the thermal interface material displays the highest thermal conductivity, and the composite also demonstrates satisfactory mechanical properties. This study proposes a promising strategy for the preparation of composites with high thermal conductivity.

Effect of the stearic acid modified metakaolin on sulfate resistance of mortar based on the experimental study and capillary theory analysis

In this study, a stearic acid modified metakaolin (MMK) was developed to improve the sulfate resistance of cement-based materials, which could effectively avoid the adverse effects of traditional hydrophobic modifier on the mechanical properties of cement mortar itself. Firstly, the effects of the stearic acid content and grinding time on the water contact angle of the MMK were studied, and the results showed that the MMK had the maximum water contact angle when the stearic acid content was 5% and the grinding time was 20 min. On this basis, abundant systematic tests were conducted to study the effects of the MMK mass fraction on water contact angle and water absorption of the mortar. Subsequently, the sulfate resistance of the mortar with MMK was examined under partial immersion, including the apparent morphology, linear expansion rate, relative dynamic elastic modulus, compressive strength and microstructure. Finally, a mathematic model considering water absorption and evaporation was developed, and the effects of the MMK on the corrosion height, capillary absorption and water evaporation of the specimen under partial immersion in sulfate solution were analyzed. The model analysis showed that the MMK could reduce the capillary water absorption height of the specimen under partial immersion in sulfate solution, and the mechanism of sulfate resistance for the mortar with the MMK was to reduce the amount of corrosive ions by reducing the capillary coefficient.

Development, QbD based optimization and in vitro characterization of Diacerein loaded nanostructured lipid carriers for topical applications

ObjectiveDCN is a chondro-protective agent which displays inadequate oral bioavailability along with gastrointestinal side effects. It is a choice of drug for treatment of osteoarthritis. Therefore, the objective of this study was to develop and optimize DCN loaded nanostructured lipid carrier (NLCs) for topical delivery. MethodNLCs were prepared by hot homogenization followed by sonication method. The formulation was optimized by 2 factor 3 level central composite design taking two independent variables i.e. concentration of stearic acid (A) and concentration of oleic acid (B), and three independent variables, particles size (Y1), % entrapment efficiency (Y2) and % drug release at 24 hours(Y3). ResultThe particle size, % entrapment efficiency and in-vitro drug release at 24 hours of optimized formulation was found 173.76 nm, 91.30%, and 94.17% respectively. The optimized DCN-NLC formulations were analyzed by DSC and XRD, TEM, and FTIR studies. DCN-NLC loaded gel was prepared and characterized for physical examination, viscosity and stability parameters. DCN-NLC in the gel form displayed sustained drug release and significant (p<0.05) tissue penetration in vitro in comparison to plain gel and DCN solution. The drug release kinetics study illustrated the Higuchi’s release pattern for prolonged period of time. Ex vivo permeation study result supported good topical penetration for DCN using DCN-NLCs. ConclusionConclusively, the developed formulation has potential for topical application for future pre-clinical studies.