Search Results (33)

This study explored the extraction of genistein-7-O-[α-rhamnopyranosyl-(1→6)]-β-glucopyranoside (GTG) from Derris scandens using an aqueous-ethanol solvent system, aiming to optimize yield and antioxidant activity. Hansen solubility parameters (HSP) were employed to determine the optimal solvent composition, with the highest GTG yield (6.83 ± 0.06 mg/g dried weight) obtained from 50% ethanol—correlating well with HSP predictions. Ultrasonic extraction was most effective with solvents having a dielectric constant between 50 and 60. The antioxidant potential of isolated GTG was evaluated using the DPPH assay, which yielded an IC₅₀ of 87.86 ± 1.85 μM, and the FRAP assay, with a value of 34.23 ± 2.75 mg FeSO₄ equivalents. Molecular orbital analysis revealed HOMO and LUMO energy gaps (ΔE = 10.6715 eV) similar to known antioxidants such as gallic acid, ascorbic acid, Trolox, and quercetin. These findings demonstrate that HSP effectively guided solvent selection for ultrasound-assisted extraction of GTG. The antioxidant activity is attributed to GTG’s capacity to donate electrons and stabilize radicals via extended charge delocalization within the aglycone structure, confirming its potential as a natural antioxidant agent. Full article

The transition toward sustainable conservation practices requires a scientifically ground approach to substituting traditional solvent systems with green alternatives. This study aims to facilitate the adoption of green solvents by restoration professionals by systematically evaluating their chemical compatibility and toxicological safety. By integrating Hansen solubility parameters (HSP), Relative Energy Difference (RED), and the Integrated Toxicity Index (ITI), we identified green solvents with high potential for replacing Cremonesi mixtures. The analysis revealed that ether-based solvents, such as 2,5-dimethyltetrahydrofuran and cyclopentyl methyl ether, exhibit high chemical affinity with Cremonesi mixtures, while esters and fatty acid methyl esters (FAMEs) offer a balanced combination of solubility and low toxicity. However, the study also underscores significant gaps in safety data (SDS) for many innovative solvents, highlighting the need for further toxicological evaluation before widespread implementation. Full article

Accurately determining the Hansen solubility parameters (HSPs) of fuel cell ionomers is crucial for optimizing the dispersion and dispersive state of the ionomer in fuel cell catalyst inks. This directly impacts the structure and coating process of the catalyst layer in proton exchange membrane fuel cells (PEMFCs). The Hansen solubility parameters (HSPs) of the Nafion ionomer were calculated by the Hansen solubility parameter software (HSPiP), inverse gas chromatography (IGC), and group contribution methods. The applicability and accuracy of the different algorithms are discussed. It was found that the solubility parameters (SPs) measured by the HSPiP method were higher, while the SPs measured by the IGC and group contribution methods were lower. However, for the ionomer with both a hydrophobic backbone and hydrophilic side chain, the HSPiP method offered a more reasonable HSP determination method. The dual HSPs of Nafion calculated by the HSPiP method were found to be δ_d = 16.4 MPa^1/2 (dispersion force), δ_p = 10.5 MPa^1/2 (polar interaction), and δ_h = 8.9 MPa^1/2 (hydrogen bonding) for the hydrophobic backbone and δ_d = 15.2 MPa^1/2, δ_p = 11.7 MPa^1/2, and δ_h = 15.9 MPa^1/2 for the hydrophilic side chain. These results provide a thermodynamic basis for solvent design in fuel cell catalyst-layer fabrication. Full article

In crude oil production, large volumes of produced water are generated as a highly polluting waste byproduct. On average, at least two barrels of produced water are generated for every barrel of oil. This water contains oil traces in stable and complex emulsions. To purify it, a method is proposed based on breaking these emulsions using solvents that induce the coalescence of oil droplets, facilitating their separation from the water. The method has two main objectives: (1) To identify the characteristics a solvent must have to effectively break oil emulsions according to the Hansen solubility parameter (HSP) model. (2) To select, from 40 solvents of different chemical families, the most suitable ones based on efficiency, low toxicity, industrial availability, and cost. The experimental procedure included the following steps: (1) Contacting the solvent with produced water containing 150 ppm of oil under agitation. (2) Allowing the mixture to rest until a layer of recovered oil formed. (3) Spectrophotometric analysis of the residual oil. Three distinct HSP solubility spheres were identified, within which the most effective solvents were xylene (99.4% recovery), cyclohexane (99.5% recovery), and tetrahydrofuran (100% recovery). Their high efficiency not only facilitated oil separation but also made the recovered oil suitable for commercialization. Full article

Multi-drug delivery systems have gained increasing interest from the pharmaceutical industry. Alongside this is the interest in amorphous solid dispersions as an approach to achieve effective oral delivery of compounds with solubility-limited bioavailability. Despite this, there is limited information regarding predicting the behavior of two or more drugs (in amorphous forms) in a polymeric carrier and whether molecular interactions between the compounds, between each compound, and if the polymer have any effect on the physical properties of the system. This work studies the interaction between model drug combinations (two of ibuprofen, malonic acid, flurbiprofen, or naproxen) dispersed in a polymeric matrix of hypromellose acetate succinate (HPMCAS) using a solvent evaporation technique. Hildebrand and Hansen calculations were used to predict the miscibility of compounds as long as the difference in their solubility parameter values was not greater than 7 MPa^1/2. It was observed that the selected APIs (malonic acid, ibuprofen, naproxen, and flurbiprofen) were miscible within the formed polymeric matrix. Adding the API caused depression in the Tg of the polymer to certain concentrations (17%, 23%, 13%) for polymeric matrices loaded with malonic acid, ibuprofen, and naproxen, respectively. Above this, large crystals started to form, and phase separation was seen. Adding two APIs to the same matrix resulted in reducing the saturation concentration of one of the APIs. A trend was observed and linked to Hildebrand and Hansen solubility parameters (HSP). Full article

This study investigates the performance of cyclopentyl methyl ether (CPME) in the extraction of fenugreek seed oil, aiming to replace the conventionally used hexane. The efficiency of this alternative solvent was evaluated first through in silico methods (based on Hansen Solubility Parameters (HSPs) and Conductor-like Screening Model for Real Solvent (COSMO-RS) simulations), followed by experimental studies. Solubility computational predictions analysis revealed that CPME exhibits superior solvation power compared to hexane. Experimentally, CPME demonstrated a significantly higher oil yield (7.23%) compared to hexane (4.25%) and a better retention of beneficial unsaturated fatty acids than hexane. Additionally, the physicochemical properties of oils extracted with CPME showed enhanced oxidative stability, sterol, tocopherol, and phenolic contents, leading to superior antioxidant and antibacterial activities. Importantly, CPME’s low volatile organic compound (VOC) emissions further establish it as a more sustainable and environmentally friendly alternative to hexane, aligning with contemporary goals of reducing harmful emissions in extraction processes. Thus, this paper highlights the functional advantages of CPME, focusing on its efficiency, selectivity, and enhanced retention of bioactive compounds, positioning it as a superior extraction solvent for fenugreek seed oil compared to hexane. Full article

The use of organic solvents, particularly those of a non-polar nature, is a common practice during cleaning operations in the restoration of polychrome artworks and metallic artifacts. However, these solvents pose significant risks to the health of operators and the environment. This study explores the formulation of innovative gels based on non-polar solvents and cellulose derivatives, proposing a safe and effective method for cleaning metallic artworks. The study is focused on a toxic apolar solvent, Ligroin, identified as one of the most widely used solvents in the cultural heritage treatments, and some “green” alternatives such as Methyl Myristate and Isopropyl Palmitate. The main challenge lies in overcoming the chemical incompatibility between non-polar solvents and polar thickening agents like cellulose ethers. To address this problem, the research was based on a hydrophilic–lipophilic balance (HLB) system and Hansen solubility parameters (HSPs) to select appropriate surfactants, ensuring the stability and effectiveness of the formulated gels. Stability, viscosity, and solvent release capacity of gels were analyzed using Static Light Multiple Scattering (Turbiscan), viscometry, and thermogravimetric analysis (TGA). The efficacy of cleaning in comparison with Ligroin liquid was evaluated on a metal specimen treated with various apolar protective coatings used commonly in the restoration of metallic artifacts, such as microcrystalline waxes (Reswax, Soter), acrylic resins (Paraloid B44), and protective varnishes (Incral, Regalrez). Multispectral analysis, digital optical microscopy, FTIR spectroscopy, and spectrocolorimetry allowed for the assessment of the gels’ ability to remove the different protective coatings, the degree of cleaning achieved, and the presence of any residues. The results obtained highlight the ability of the formulated gels to effectively remove protective coatings from metallic artifacts. Cetyl Alcohol proved to be the most versatile surfactant to realize a stable and efficient gel. The gels based on Methyl Myristate and Isopropyl Palmitate showed promising results as “green” alternatives to Ligroin, although in some cases, they exhibited less selectivity in the removal of protective coatings. Full article

The fouling of protein on the surface of reverse osmosis (RO) membranes is a surface phenomenon strongly dependent on the physical and chemical characteristics of both the membrane surface and the foulant molecule. Much of the focus on fouling mitigation is on the synthesis of more hydrophilic membrane materials. However, hydrophilicity is only one of several factors affecting foulant attachment. A more systematic and rationalized methodology is needed to screen the membrane materials for the synthesis of fouling-resistant materials, which will ensure the prevention of the accumulation of foulants on the membrane surfaces, avoiding the trial and error methodology used in most membrane synthesis in the literature. If a clear correlation is found between various membrane surface properties, in combination or singly, and the amount of fouling, this will facilitate the establishment of a systematic strategy of screening materials and enhance the selection of membrane materials and therefore will reflect on the efficiency of the membrane process. In this work, eight commercial reverse osmosis membranes were tested for bovine serum albumin (BSA) protein fouling. The work here focused on three surface membrane properties: the surface roughness, the water contact angle (hydrophilicity), and finally the Hansen solubility parameter (HSP) distance between the foulant understudy (BSA protein) and the membrane surface. The HSP distance was investigated as it represented the affinities of materials to each other, and therefore, it was believed to have an important contribution to the tendency of foulant to stick to the surface of the membrane. The results showed that the surface roughness and the HSP distance contributed to membrane fouling more than the hydrophilicity. We recommend taking into account the HSP distance between the membrane material and foulants when selecting membrane materials. Full article

Background: Suk-Saiyasna is a traditional Thai herbal remedy that comprises 12 distinct herbs. Among these, cannabis leaves constitute 12 of the total 78 components in this formulation. This study specifically examines the portion of the cannabis plant, which accounts for approximately 15.8% of the overall herbal composition used in the entire remedy. According to the Thailand Narcotics Act of 2022, the Δ9-tetrahydrocannabinol (Δ9-THC) concentration in herbal extracts must not exceed 0.2% by weight. This study aims to quantify the levels of Δ9-THC and cannabidiol (CBD) in commercial Suk-Saiyasna products. Methodology: This research utilizes Hansen Solubility Parameters (HSPs) to identify the optimal solvent for ultrasonic extraction, thereby maximizing cannabinoid yield. An advanced method was developed employing ultra-high-performance liquid chromatography–tandem mass spectrometry (UHPLC-MS/MS), compliant with AOAC standards to meet regulatory guidelines. The method validation emphasized specificity, linearity, sensitivity, accuracy, and precision. Results: Dichloromethane was chosen due to its favorable HSP values, enabling highly efficient extraction of Δ9-THC and CBD, achieving recovery rates of over 99.9% after the second extraction. This investigation benefits from the accuracy of the UHPLC-MS/MS technique in quantifying cannabinoids in commercial products, with Δ9-THC concentrations observed between 0.00231% and 0.14218%, and CBD concentrations ranging from 0.00002% to 0.01541%, all remaining below the legal limit. Conclusions: The variability in cannabinoid concentrations among various commercial products highlights the need for standardization in the herbal industry. This finding underscores the critical role of rigorous quality control measures in ensuring the safety and efficacy of cannabis-derived products. Full article

A styrene-butadiene-styrene co-polymer matrix nanocomposite filled with graphene nanoplatelets was studied to prepare chemiresistive volatile organic compounds (VOCs) room temperature sensors with considerable response and selectivity. Nanofiller concentration was estimated from the electrical conductivity percolation behaviour of the nanocomposite. Fabricated sensors provided selective relative responses to representative VOCs differing by orders of magnitude. Maximum observed average relative responses upon exposure to saturated vapours of the tested VOCs were ca. 23% for ethanol, 1600% for acetone, and the giant values were 9 × 10⁶% for n-heptane and 10 × 10⁶% for toluene. The insensitivity of the sensor to the direct saturated water vapour exposure was verified. Although high humidity decreases the sensor’s response, it paradoxically enhances the resolution between hydrocarbons and polar organics. The non-trivial sensing mechanism is explained using the Hansen solubility parameters (HSP), enabling a rational design of new sensors; thus, the HSP-based class of sensors is outlined. Full article

The physical blending method was used in order to prepare nitrile-butadiene rubber/polyamide elastomer/single-walled carbon nanotube (NBR/PAE/SWCNT) composites with better thermal-oxidative aging resistance. The interactions between SWCNTs and NBR/PAE were characterized using the Moving Die Rheometer 2000 (MDR 2000), rheological behavior tests, the equilibrium swelling method, and mechanical property tests. The 100% constant tensile stress and hardness of NBR/PAE/SWCNT composites increased from 2.59 MPa to 4.14 MPa and from 62 Shore A to 69 Shore A, respectively, and the elongation decreased from 421% to 355% with increasing SWCNT content. NBR/PAE/SWCNT composites had improved thermal-oxidative aging resistance due to better interactions between SWCNTs and NBR/PAE. During the aging process, the tensile strength and elongation at break decreased with the increase in aging time compared to the unaged samples, and the constant tensile stress gradually increased. There was a more significant difference in the degradation of mechanical properties when aged in a variety of oils. The 100% constant tensile stress of NBR/PAE/SWCNT composites aged in IRM 903 gradually increased with aging time while it gradually decreased in biodiesel. The swelling index gradually increased with increasing SWCNT content. Interestingly, the swelling index of the composites in cyclohexanone decreased with the increase in SWCNT content. The reasons leading to different swelling behaviors when immersed in different kinds of liquids were investigated using the Hansen solubility parameter (HSP) method, which provides an excellent guide for the application of some oil-resistant products. Full article

The reported total Hildebrand solubility parameter (δ₂) value of meloxicam, as calculated based on the group contribution method proposed by Fedors, was compared with those estimated based on the maximum solubility peaks observed in different aqueous cosolvent systems at T = 298.15 K. Thus, the observed δ₂ values varied from (19.8 to 29.1) MPa^1/2, respectively. Moreover, the Hansen solubility parameters (HSPs) and the total Hildebrand solubility parameter were also determined by using the Bustamante regression method with the reported experimental solubility values of meloxicam in 31 neat solvents (30 organic solvents and water), obtaining the values: δ_d = 19.9 MPa^1/2, δ_p = 16.9 MPa^1/2, δ_h = 5.7 MPa^1/2, and δ_T = 26.7 MPa^1/2. Furthermore, the HSPs of meloxicam were also estimated based on the Hoftyzer–van Krevelen group contribution method, obtaining the values: δ_d = 17.9 MPa^1/2, δ_p = 20.3 MPa^1/2, and δ_h = 9.2 MPa^1/2, and the total solubility parameter as: δ_T = 28.6 MPa^1/2. In addition, the Kamlet–Abboud–Taft linear solvation energy relationship (KAT-LSER) model was also employed to evaluate the role of different intermolecular interactions on the dissolution of meloxicam in different solvents that varied in terms of polarity and hydrogen bonding capability. Full article

To achieve the target colors, pigmentation (post-processing) in solvents is a key process in making Pigment Yellow 180 (PY180), a bis azo pigment. In this work, the solvent effect on the pigmentation behavior of PY180 was studied based on the Hansen solubility parameters (HSPs) and the molecular polarity index (MPI) method. First, the samples were characterized using FTIR, XRD, and TEM, and the colorimetric analysis was performed using the CIE L*a*b* color space model. It was found that the color hues obtained in ten solvents are different, with the overall color variation from reddish–yellow to greenish–yellow. Further characterization confirmed that the crystallinity and particle size increase of PY180 during the pigmentation mainly account for the variation of the chromaticity. Then, HSPs were introduced to understand how suspension behavior affects the dissolution–reprecipitation process. It shows that high-quality pigments can be obtained from solvents generally with low HSP differences (Δδ) between the solvents and PY180. To compensate for the inaccurate prediction of the HSPs method, MPI was used to value the influence of solvent molecular polarity. The results show that among solvents with similar solubility parameters to PY180, the stronger the molecular polarity index (MPI) of the solvent, the greater the color variation of the pigments. Meanwhile, different solvents influence the crystallization behavior of the low soluble system, which was supplemented by the above study. Full article

The Hansen solubility parameter (HSP) is a useful index for reasoning the gelation behavior of low-molecular-weight gelators (LMWGs). However, the conventional HSP-based methods only “classify” solvents that can and cannot form gels and require many trials to achieve this. For engineering purposes, quantitative estimation of gel properties using the HSP is highly desired. In this study, we measured critical gelation concentrations based on three distinct definitions, mechanical strength, and light transmittance of organogels prepared with 12-hydroxystearic acid (12HSA) and correlated them with the HSP of solvents. The results demonstrated that the mechanical strength, in particular, strongly correlated with the distance of 12HSA and solvent in the HSP space. Additionally, the results indicated that the constant volume-based concentration should be used when comparing the properties of organogels to a different solvent. These findings are helpful in efficiently determining the gelation sphere of new LMWGs in HSP space and contribute to designing organogels with tunable physical properties. Full article

Promethazine hydrochloride (PM) is a widely used drug so its determination is important. Solid-contact potentiometric sensors could be an appropriate solution for that purpose due to their analytical properties. The aim of this research was to develop solid-contact sensor for potentiometric determination of PM. It had a liquid membrane containing hybrid sensing material based on functionalized carbon nanomaterials and PM ions. The membrane composition for the new PM sensor was optimized by varying different membrane plasticizers and the content of the sensing material. The plasticizer was selected based on calculations of Hansen solubility parameters (HSP) and experimental data. The best analytical performances were obtained using a sensor with 2-nitrophenyl phenyl ether (NPPE) as the plasticizer and 4% of the sensing material. It had a Nernstian slope (59.4 mV/decade of activity), a wide working range (6.2 × 10⁻⁷ M–5.0 × 10⁻³ M), a low limit of detection (1.5 × 10⁻⁷ M), fast response time (6 s), low signal drift (−1.2 mV/h), and good selectivity. The working pH range of the sensor was between 2 and 7. The new PM sensor was successfully used for accurate PM determination in a pure aqueous PM solution and pharmaceutical products. For that purpose, the Gran method and potentiometric titration were used. Full article