Polyol Solution Research Articles

Ammonia detection based on Pd/Rh-GaN and recognition of disease markers of nitrogen compounds assistant by deep learning

Bimetallic has received a lot of attention due to its excellent catalytic performance. Herein, bimetallic nanofilms were successfully modified on GaN epitaxial wafer by a co-reduction method in polyol solution, and different concentrations of Pd/Rh-GaN were obtained. Meanwhile, the morphology and structure of Pd/Rh-GaN were subjected to a series of measurements, and the gas sensors modified with bimetallic modification were also studied for gas sensitivity. The results of the gas-sensitive properties show that the Pd/Rh-GaN-0.25 sensor has outstanding gas-sensing performance with the highest sensitivity, the lowest limit of detection, and the fastest response/recovery time. In addition, we extended other bimetallic nanoparticles to Pd/Ru and Pt/Ru, and deep learning was combined with the sensor array to recognize three markers of nitrogen compounds (NH3, NO2, TMA) in Exhaled breath, achieving high precision recognition with up to 96 % accuracy. This work offers a new approach for the design and preparation of gas sensors for early warning of chronic kidney disease.

Phase behaviour and thermodynamics of triton X-100 + metformin hydrochloride mixture: influences of several polyols and polymer media

The applications of surfactants and drugs in a wide variety of fields such as pharmaceuticals, food industry, textile, fabrics, etc. are increasing significantly. Herein, we investigated the clouding behavior and thermodynamics of triton X-100 (TX-100) and metformin hydrochloride (MNH) drug mixture in the effect of several polyols and polyethylene glycol (PEG) polymer. The phase separation behavior of the mixture of TX-100 + MNH has been deduced with the help of the cloud point technique. The cloud point (CP) values for the TX-100 and drug mixtures were documented in a decreased and increased manner with the augmentation of the concentration of polyol and PEG respectively. With the subsequent enhancement of polyol and PEG content, the CP values were recorded in the following order: C P H 2 O + PEG > C P H 2 O + fructose > C P H 2 O + glucose > C P H 2 O + galactose > C P H 2 O + maltose . The standard enthalpy change ( Δ H c o ) and entropy change ( Δ S c o ), of TX-100 + MNH mixture in aq. polyols solutions were documented as negative; the negative values reduce in magnitudes with the polyols contents and become positive at the highest polyol content while opposite trend was obtained in presence of PEG. The presence of electrostatic and hydrophobic interactions among TX-100/MNH/polyols/polymer has been recommended as the interaction forces.

Stimulation of secondary metabolism in grape berry exocarps by a nature-based strategy of foliar application of polyols

In grapes under drought stress, polyols accumulate through tight coordination at the molecular level between increased membrane transport of polyols and inhibition of polyol oxidation. Here, the effects on grape metabolism of an exogenous foliar application of polyols as a potential sustainable viticultural practice to increase grapevine performance and berry quality were thoroughly assessed. Grapevines were pulverised with a polyol solution containing 2 mM mannitol and 2 mM sorbitol, and the metabolome of grape berry exocarps and important metabolic pathways associated with berry quality and polyol metabolism were analysed at véraison and mature stages. By combining metabolomics analysis using UPLC-MS, enzyme activity assays and targeted transcriptional analyses, it was demonstrated that foliar application of polyols stimulated by 3.5-fold and 6-fold abscisic acid (ABA) biosynthesis at véraison and mature grape berries, respectively. It also stimulated the concentration of anthocyanins, stilbenes and total phenolics in exocarps through the upregulation of phenylpropanoid, stilbenoid and anthocyanin biosynthetic pathways shown by increases in phenylalanine-ammonia lyase (PAL) activity (3-fold) and VviPAL1 expression, stilbene synthase 1 (VviSTS1) transcripts (ca. 5-fold), UDP-glucose:flavonoid 3-O-glucosyltransferase (UFGT) activity and VviUFGT1 expression, among other results, at the mature stage, when these changes were most noticeable. Many secondary metabolites synthesised in these pathways identified by UPLC-MS analysis were present at higher quantities in exocarps from polyol-treated plants such as fertaric acid, E-resveratrol, E-piceatannol, piceid, pallidol, E-ε-viniferin, myricetin-hexoside 1, cyanidin-3-O-glucoside and malvidin-3-O-(6-p-coumaroyl)-glucoside. Foliar application of low-concentration polyols is, therefore, a promising biostimulant-based strategy to improve grape berry quality and nutritional value in the current context of climate change.

Ultrasound-assisted facile and green preparation of Ag nanoparticle conductive ink for printing electronics

The development of low-cost, high-efficiency, and environment-friendly methods for the preparation of Ag nanoparticle (NP) conductive inks is key to promoting the application of such inks for printing flexible electronic components. This article presents an effective method for preparing a AgNP ink by reducing silver compounds in a polyol solution with ultrasonication. When the silver solution was ultrasonicated at 640 W, 21-nm AgNPs were readily produced within 5 min, and the particles grew considerably to 53 nm as the reaction was continued for 15 min. Thereafter, the NP size increased marginally with further increase in reaction time. When the reaction was conducted for a fixed duration of 15 min and the ultrasonic power was increased from 480 to 760 W, the AgNP size decreased from 63 to 48 nm. During ultrasonication, the bubble eruption in the solution generates large temperature and pressure gradients, inducing the rapid reduction of the Ag(I) to Ag(0). Printing experiments revealed that the synthesized AgNP ink has good inkjet printability. During the sintering of the printed film, the bridge connections between large particles increased and the interparticle voids decreased gradually, resulting in a decrease in film resistivity. A relatively low resistivity of 40×10−5 Ωcm was obtained when the flexible AgNP pattern was heated at 250 °C for 80 min. The facile synthesis process and the favorable conductive properties of the obtained ink render this preparation method promising for the low-cost production of flexible electronics.

Polyol Synthesis of Nanoparticles: A Decade of Advancements and Insights

This article presents a focused overview of advancements in the field of polyol synthesis of metal, metal oxide nanoparticles and nanocomposites, specifically those reported in the current decade. The aim of this article is to present the pertinent physico-chemical factors associated with nanoparticle synthesis in polyol solutions, highlighting their applications in both biological and industrial domains. The scope of this review article is selective rather than exhaustive, concentrating on noteworthy contributions to polyol nanoparticle synthesis that hold potential for refining synthesis methods. To comprehend the role of polyols in nanoparticle synthesis, an examination of the distinct physical properties of various polyols is crucial. Moreover, understanding the particular functions and mechanisms governing nanoparticle formation is imperative in this context.

Engineering the photo-induced charge generation between TiO2 and FeS2 heterojunction for enhanced photocatalytic wastewater purification

Wastewater treatment using photocatalytic processes is an eco-friendly approach to tackle the scarcity of drinkable water. In this study, a heterojunction of TiO2 and FeS2 nanostructures was synthesized via a one-pot polyol method, and their activity was investigated in eliminating crystal violet as a dye pollutant. The difference in the thermodynamic stability of iron and titanium oxides in polyol solution containing thiourea led to the formation of TiO2 nanorods and sulfurization of iron in the form of FeS2 nanospheres. Incorporating TiO2 nanorods with FeS2 chalcogenide nanostructures narrowed the band gap energy (from 3.05 to 2.6 eV) and enhanced the photo-induced charge carriers’ separation by forming an internal electric field. Compared to TiO2 nanorods, the synthesized heterojunction photocatalyst using 0.5 ml TBOT (FST-0.5) exhibited the best activity and increased crystal violet degradation from 55% to 89%. The optimization and modeling of the interaction between operating parameters were performed by response surface methodology based on central composite design. The statistically significant quadratic polynomial model was best for fitting the experimental data. Regarding this model, adjusting the catalyst weight, pollutant concentration, and solution pH at an optimum amount of 0.015 g, 4 ppm, and 9 causes the highest photocatalytic degradation, around 94%. The kinetics studies also revealed that photocatalytic degradation follows first-order kinetics with an apparent rate constant of 0.0184 min−1. The contribution of active species was determined by free-radical capture experiment. Herein, photo-holes had the main contribution (38.3%), and the rest accounted for hydroxide radicals (26.6%), superoxide anions (11.7%), and electrons (23.4%).

Natural deep eutectic solvents as a green extraction of polyphenols from spent coffee ground with enhanced bioactivities.

Conventional extraction techniques are usually based on highly pollutant and/or flammable organic solvents. Therefore, alternative environmentally friendly extraction methods are of particular interest for the recovery of bioactive compounds for their application as food ingredients and/or nutraceuticals. Natural deep eutectic solvents (NADES) are a green and nontoxic attractive alternative to hydroalcoholic extraction. NADES media primarily depends on the intermolecular interactions (hydrogen bonding) among their components to form a eutectic mixture with a much lower final melting point than its individual components. Examples of natural deep eutectic NADES solvents include aqueous solutions (25%-50% water) of choline chloride, sugars, and polyols. This study aimed to investigate the application of two NADES, namely, betaine:triethylene glycol (Bet : TEG) and choline chloride:1,2-propanediol (Chol : Prop), as sustainable green solvents for the extraction of polyphenols from spent coffee ground (SCG), a by-product of coffee processing. In particular, the extraction yield and selectivity were evaluated and compared with conventional green extractions (hot water and a hydroalcoholic solution). In addition, the effect of NADES on the antioxidant and antimicrobial activity of the extracts was investigated. The main outcomes were as follows: (i) NADES were as effective as other conventional green solvents in the extraction of polyphenols with the added advantage of operating at milder temperature conditions, without flammable solvents and with sustainable and natural compounds; (ii) the antimicrobial activity of the NADES extracts was 10 times higher than that of the ethanolic and aqueous extracts. Given the low toxicity of NADES, they could be used as formulation aid for food ingredients.

Rigid composite bio-based polyurethane foams: From synthesis to LCA analysis

This paper provides a bio-based polyurethane foam (PUR) solution, following a cradle-to-factory approach. The design of bio-based rigid PURs, reinforced with sustainable fillers have gained remarkable attention in “green” construction sector. Their marked performances make them a viable solution for synthetic counterparts' replacement. In this work, functionalized hemp fibers and silica powders were selected as reactive fillers, imparting multifunctional properties to the designed PURs. Hemp fibers underwent ultramilling, phenolation and/or nano-transformation to obtain four different filler types, i.e. nano- and micro-sized hemp particles, and functionalized hemp nano and micro-size couples. Silica nanoparticles were extracted from rice husk and functionalized with phytic acid. The composite PURs were prepared by adding 6 % wt of filler to cardanol/vegetable-based polyol solutions. The effect of the filler's chemistry on the properties of the foams was investigated. A Life Cycle Assessment of the filler production stages was performed to assess their eco-profile impact.

Highly selective gas sensor for rapid detection of triethylamine using PdRu alloy nanoparticles functionalized SnO2

Triethylamine is a kind of volatile organic compound, which is flammable and toxic. Here, PdRu alloy nanoparticles (NPs) were used for modifying SnO2 to make it more selective for triethylamine. Monodisperse PdRu alloy NPs were produced through coreduction in polyol solution, while the SnO2 nanoparticles with a small particle size were generated by a hydrothermal method. The sensor based on 0.5 wt% PdRu-SnO2 exhibited a high response (S = 256) to 100 ppm triethylamine when the temperature was 220 °C. The response was 12 times more than trimethylamine and 10 times higher than that to NH3. Moreover, it showed rapid response speed (2 s) to triethylamine. SnO2 with small particle size had many acid sites, which showed selective detection of triethylamine due to acid-base reaction. Besides, the catalytic property of PdRu NPs also played a role in improving performance. This work provides a new method for the fast identification of triethylamine in chemical industry plant.

Surfactant in a Polyol-CO2 Mixture: Insights from a Classical Density Functional Theory Study.

Silicone-polyether (SPE) surfactants, made of a polydimethyl-siloxane (PDMS) backbone and polyether branches, are commonly used as additives in the production of polymeric foams with improved properties. A key step in the production of polymeric foams is the nucleation of gas bubbles in the polymer matrix upon supersaturation of dissolved gas. However, the role of SPE surfactants in the nucleation of gas bubbles is not well understood. In this study, we use classical density functional theory to investigate the effect of an SPE surfactant on the nucleation of CO2 bubbles in a polyol foam formulation. We find that the addition of an SPE surfactant leads to a ∼3-fold decrease in the polyol-CO2 interfacial tension at the surfactant's critical micelle concentration. Additionally, the surfactant is found to reduce the free energy barrier and affect the minimum free energy pathway (MFEP) associated with CO2 bubble nucleation. In the absence of a surfactant, a CO2-rich bubble nucleates from a homogeneous CO2-supersaturated polyol solution by following an MFEP characterized by a single nucleation barrier. Adding a surfactant results in a two-step nucleation process with reduced free energy barriers. The first barrier corresponds to the formation of a spherical aggregate with a liquid-like CO2 core. This spherical aggregate then grows into a CO2-rich bubble (spherical aggregate with a vapor-like CO2 core) of a critical size representing the second barrier. We hypothesize that the stronger affinity of CO2 for PDMS (than polyether) stabilizes the spherical aggregate with the liquid-like CO2 core, leading to a lower free energy barrier for CO2 bubble nucleation. Stabilization of such an aggregate during the early stages of the nucleation may lead to foams with more, smaller bubbles, which can improve their microstrustural features and insulating abilities.

Reducing chilling injury in 'Palmer' mangoes submitted to quarantine cold treatment.

Treatment with low temperatures can be used to quarantine mangoes against fruit-fly infestation. However, mangoes can develop chilling injury (CI) when stored at temperatures below 13 °C. We demonstrated that the immersion in polyol solutions can alleviate CI symptoms in 'Palmer' mangoes stored at 8°C. These suggest that polyols can be used to reduce CI in mangoes during quarantine at low temperatures. Thus, we investigated the efficacy of applying 0.1% (v/v) glycerol, propylene glycol, or sorbitol to 'Palmer' mangoes subjected to cold treatment (1.0°C) for 28 days. Mangoes were then ripened at 23 °C for 7 days. Among these polyols, sorbitol was the most effective in alleviating CI for up to 14 days of cold treatment. Mangoes treated with sorbitol showed lower levels of malondialdehyde (MDA) and hydrogen peroxide (H2 O2 ), and reduced polyphenol oxidase (PPO) activity. These fruit also had elevated levels of ascorbate (AsA), especially in the epicarp, and increased superoxide dismutase (SOD), catalase (CAT), and ascorbate peroxidase (APX) activity. Sorbitol can reduce the CI, but to an unsatisfying level, and it should be combined with other treatments storage at low temperature. © 2022 Society of Chemical Industry.

The Influence of Polyols on the Process Kinetics and Bioactive Substance Content in Osmotic Dehydrated Organic Strawberries.

In recent years, an increasing interest in reducing sugar consumption has been observed and many studies are conducted on the use of polyols in the osmotic dehydration process to obtain candied or dried fruits. The studies in the literature have focused on the kinetics of the process as well as the basic physical properties. In the scientific literature, there is a lack of investigation of the influence of such polyol solutions such as sorbitol and mannitol used as osmotic substances during the osmotic dehydration process on the contents of bioactive components, including natural colourants. Thus, the aim of the study was to evaluate the impact of polyols (mannitol and sorbitol) in different concentrations on the process kinetics and on chosen physical (colour and structural changes) as well as chemical (sugars and polyol content, total anthocyanin content, total polyphenol content, vitamin C, antioxidant activity) properties of osmotic-dehydrated organic strawberries. Generally, the results showed that the best solution for osmotic dehydration is 30% or 40% sorbitol solutions, while mannitol solution is not recommended due to difficulties with preparing a high-concentration solution and its crystallization in the tissue. In the case of sorbitol, the changes of bioactive compounds, as well as colour change, were similar to the sucrose solution. However, the profile of the sugar changed significantly, in which sucrose, glucose, and fructose were reduced in organic strawberries and were partially replaced by polyols.

Cryogenic thermal insulating and mechanical properties of rigid polyurethane foams blown with hydrofluoroolefin: Effect of perfluoroalkane

The effect of perfluoroalkane (PFA) on the morphology, thermal conductivity, mechanical properties and thermal stability of rigid polyurethane (PU) foams was investigated under ambient and cryogenic conditions. The PU foams were blown with hydrofluorolefin. Morphological results showed that the minimum cell size (153 μm) was observed when the PFA content was 1.0 part per hundred polyols by weight (php). This was due to the lower surface tension of the mixed polyol solution when the PFA content was 1.0 php. The thermal conductivity of PU foams measured under ambient (0.0215 W/mK) and cryogenic (0.0179 W/mK at −100°C) conditions reached a minimum when the PFA content was 1.0 php. The low value of thermal conductivity was a result of the small cell size of the foams. The above results suggest that PFA acted as a nucleating agent to enhanced the thermal insulation properties of PU foams. The compressive and shear strengths of the PU foams did not appreciably change with PFA content at either −170°C or 20°C. However, it shows that the mechanical strengths at −170°C and 20°C for the PU foams meet the specification. Coefficient of thermal expansion, and thermal shock tests of the PU foams showed enough thermal stability for the LNG carrier’s operation temperature. Therefore, it is suggested that the PU foams blown by HFO with the PFA addition can be used as a thermal insulation material for a conventional LNG carrier.

Efficiency of Osmotic Dehydration of Pomegranate Seeds in Polyols Solutions Using Response Surface Methodology

This study investigates the influence of polyol compounds (sorbitol and erythritol) on the osmotic dehydration process of pomegranate seeds. The efficacy of the osmotic dehydration process was estimated based on the determination of water loss, weight reduction, solid gain, and effective diffusivity and also through a comparison of the results obtained between sucrose and polyol osmotic solutions. Response surface methodology was used to optimize the osmotic process. Quality attributes of pomegranate seeds were determined through the assessment of physical (texture and color) characteristics. This innovative research applies alternative solutions in the osmotic process, which until now, have not been commonly used in the osmotic dehydration of pomegranate seeds processing by researchers worldwide. Results revealed the excellent correlation of experimental values with the model. Erythritol and sorbitol exhibit stronger efficiency than sucrose. However, erythritol was not satisfactory due to the high solid gain. Therefore, the sorbitol osmotic agent seems to be the most suitable for the osmotic dehydration of pomegranate seeds. The optimal condition for maximum water loss (38.61%), weight reduction (37.77%), and effective diffusivity (4.01 × 10−8 m2/s) and minimum solid gain (−0.37%) were 13.03 min, 27.77 °Brix, and 37.7 °C, using a sorbitol solution. Results of texture and color revealed the major impact of erythritol and sorbitol osmotic agents on seed characteristics during the osmotic dehydration process.

Diets of erythritol, xylitol, and sucrose affect the digestive activity and gut bacterial community in adult house flies

AbstractPolyol sweeteners, including erythritol and xylitol, have been investigated for their potential in insect control against a number of pests including mosquitoes, fruit flies, ants, and filth flies. Several insecticidal modes of action for the polyols have been proposed in non‐biting flies and include: (1) dehydration from excessive regurgitation, (2) arrestment of physiological processes due to abnormally high hemolymph osmolality or osmotic diarrhea, and (3) alteration of the gut microbiome. Here, we explored the proposed modes of action in the house fly, Musca domestica L. (Diptera: Muscidae), a non‐biting fly of medical and veterinary importance. House flies fed erythritol or xylitol regurgitated at a significantly higher rate when compared to flies that ingested sucrose. Flies that ingested sucrose solutions had higher hemolymph osmolality than erythritol but not xylitol, and deposited significantly more fecal spots than flies fed polyol solutions. Cultivable bacteria were least abundant in flies fed solutions of either sucrose or xylitol and most abundant in control flies provided water only. Of the potential modes of action tested, physiological stress from excessive post‐feeding regurgitation seems the likeliest cause of death related to polyol consumption. However, we cannot rule out a classical toxicological or biochemical mode of action from these results. Although the efficacy of polyols as active ingredients is still under debate, their use as other components in fly control products may be beneficial. Due to widespread resistance to a limited number of insecticidal chemicals registered for house fly control, it is important that new control chemicals be thoroughly assessed for usefulness.

Influences of alcohol/polyols on interaction of moxifloxacin hydrochloride through cetyltrimethylammonium bromide at numerous temperatures and compositions

A study on the interaction of a fourth-generation antibiotic drug, moxifloxacin hydrochloride (MFH), with a cationic surfactant, such as cetyltrimethylammonium bromide (CTAB) in the aqueous solution of alcohol (1-propanol (1-PrOH)) and polyols (galactose/maltose), has been carried out using the conductivity measurement technique. The critical micelle concentration (cmc), micelle ionisation (α), counter ion binding (β), and thermodynamic properties (, , and ) for the self-aggregation of MFH + CTAB mixture have been estimated in 1-PrOH/polyols solutions. The presence of 1-PrOH delays the MFH + CTAB micelle formation, whereas polyols create a congenial environment for the micelle formation. In 1-PrOH, the values of α experience a reduction with the increase of 1-PrOH concentration and temperature. The values of α were found to be dependent on the concentration of other additives. In all of the cases thoroughly studied, the values of were found negative, which experience an enhancement in polyols solutions and decreased in 1-PrOH solution. On the basis of and values, the suggested interaction forces between MFH and surfactant are hydrophobic, ion-dipole, and electrostatic in nature. The values of reveal that the micelle is more stable in polyols media than that of the 1-PrOH medium.

Insights into the growth of nanoparticles in liquid polyol by thermal annealing.

We report on the growth of metal- and metal-oxide based nanoparticles (NPs) in heated polyol solutions. For this purpose, NPs are produced by the sputtering of a silver, gold, or a copper target to produce either silver, gold, or copper oxide NPs in pentaerythritol ethoxylate (PEEL) which has been annealed up to 200 °C. The objective of the annealing step is the fine modulation of their size. Thus, the evolution of the NP size and shape after thermal annealing is explained according to collision/coalescence kinetics and the affinity between the metal-/metal-oxide and PEEL molecule. Moreover, highlights of few phenomena arising from the annealing step are described such as (i) the reduction of copper oxide into copper by the polyol process and (ii) the effective formation of carbon dots after annealing at 200 °C.

Preparation and in vitro tumor growth inhibitory effect of oligo (L-lactate) nanoparticles.

Oligo L-lactates (oligolactates) that have low molecular weights less than 2000 have been reported to inhibit tumor growth and extend the survival of experimental animals. Because oligolactates are scarcely soluble in water, they require a solvent or a solubilizing agent, such as a surfactant, to be dissolved in water. However, these agents are generally cytotoxic, an in vitro assay appropriate to evaluate the inhibitory effect on tumor growth has not been developed yet. Here, we prepared a solid nanodispersion of oligolactates using an oil-in-water emulsion solvent evaporation method to evaluate its tumor inhibitory activity in vitro without a solvent or surfactant. Polyol solutions containing polyvinyl alcohol (PVA) were used as a continuous phase. The formation of nanoparticles depended on the concentrations of polyol and PVA in the continuous phase. The nanoparticles with a particle size of approximately 100 nm were obtained using 10-15% PVA and 60% propylene glycol. The obtained aqueous nanodispersion of oligolactates inhibited the growth of B16-BL6 melanoma cells in vitro, whereas the medium alone did not affect tumor cell growth. Therefore, oligo(L-lactate) nanoparticles may be useful in the research and development of oligolactates as a remedy for cancer.

Effect of Polyol Molecular Structure on Fluidity, Surface Tension, and Printed Pattern Sharpness of Disperse Dye Inks.

In the present study, density functional theory (DFT) has been used in simulating and calculating the molecular geometries of differently structured polyols (within a water phase), as well as the weak interactions between these polyols and the water molecules. Furthermore, low field nuclear magnetic resonance (LF-NMR) has been used in studying the transverse relaxation times of different polyols, in addition to their (20.00 wt %) fluidity in an aqueous environment. Moreover, the influence of polyols, with different molecular structures, on the ink fluidity, was also explored. A bubble pressure tensiometer was also used to characterize the surface tension of the aqueous polyol (20.00 wt %) solution, the sodium dodecyl sulfate (SDS, 0.50 wt %) solution, and the ink. This was made to clarify the influence of polyol and SDS on the surface tension of ink. In addition, the particle size, zeta potential, pH value, viscosity, and rheological properties of the ink, were also investigated. The resulting data showed that polyols have certain effects on the particle size, stability, and viscosity of the ink. The jetting performances of different polyol inks were, under certain conditions of the inkjet drive waveform, also explored. The results showed that the fluidity, viscosity, and surface tension of the ink will render a certain influence on the inkjet performances. The prepared polyol ink was thereafter used for polyester fabric printing, and the contour sharpness and color fastness of the printed fabric were accordingly evaluated. The data showed that the increase in ink viscosity, and decrease in fluidity, promote the improvement in contour sharpness. In addition, the printed fabric demonstrated an excellent color fastness.

Moisturizing mechanism of glycerol and diglycerol on human stratum corneum studied by synchrotron X-ray diffraction.

Polyols are moisturizers used in cosmetics. Using X-ray diffraction, we studied the moisturizingmechanism of polyol solutions in the stratum corneum (SC). We examined whether glycerol disrupts the ordered hydrocarbon chain packing structure in isolated SC, as previously proposed in an SC lipid model. The SC samples were prepared by treatment with water and aqueous solutions of glycerol, diglycerol and glycerol/diglycerol. To examine the differences in the water-retention efficiency of polyols, using a solution cell, we performed dynamic X-ray diffraction to analyse the structural changes that occurred during water removal from the hydrated samples by a stream of dry nitrogen gas. We focused on two structures, the orthorhombic hydrocarbon chain packing structure in the intercellular lipids and the soft keratin in the corneocytes where most of the water is stored. The spacing formed by the soft keratin in the corneocytes immersed in a solution of water and diglycerol solution decreased rapidly by water removal. In contrast, it decreased gradually in the corneocytes immersed in a solution of glycerol and glycerol/diglycerol, indicating that the glycerol-containing solutions maintained the hydrated state of the corneocytes for longer. Furthermore, the characteristic change of the spacing in the orthorhombic hydrocarbon chain packing structure over time was observed during the drying process. The hydrated state was maintained longer, in water, followed by glycerol, diglycerol and glycerol/diglycerol, in increasing order. This is the first study to report such characteristic properties that could be indicators of the capacity of the SC to regulate water. The dynamic X-ray diffraction experiment on the structure of the soft keratin and the orthorhombic hydrocarbon chain packing structure during the drying of the hydrated SC provides an insight into the moisturizing mechanism of the polyol solutions in the SC. The results show that the glycerol/diglycerol solution functions as an effective SC moisturizer at the molecular level. Further, it was confirmed that the behaviour of glycerol in the isolated SC varies from that proposed in the SC lipid model, wherein glycerol was proposed to prevent the formation of a regular hydrocarbon chain packing structure.