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In this paper, the content of bound water was studied to evaluate the cryoprotective properties of ethylene glycol and glycerol solution. Molecular dynamic models for the solution were built, the classification principle and statistical methods of water molecules in solutions were presented, respectively. The content of bound water with various hydroxyl molarity at different temperatures was obtained through molecular dynamic simulation. The results reveal that the content of bound water increases with increasing hydroxyl molarity, but decreases with increasing temperature. It was found that, the content of bound water in ethylene glycol solution is always slightly more than that in glycerol solution, regardless of whether the temperature increases or not. [ABSTRACT FROM AUTHOR]

We examine the broadband behavior of complex electrical properties of glycerin and water mixtures over the frequency range of 0.1–25.0 GHz, especially as they relate to using these liquids as coupling media for microwave tomographic imaging. Their combination is unique in that they are mutually miscible over the full range of concentrations, which allows them to be tailored to dielectric property matching for biological tissues. While the resultant mixture properties are partially driven by differences in the inherent low-frequency permittivity of each constituent, relaxation frequency shifts play a disproportionately larger role in increasing the permittivity dispersion while also dramatically increasing the effective conductivity over the frequency range of 1–3 GHz. For the full range of mixture ratios, the relaxation frequency shifts from 17.5 GHz for 0% glycerin to less than 0.1 GHz for 100% glycerin. Of particular interest is the fact that the conductivity stays above 1.0 S/m over the 1–3-GHz range for glycerin mixture ratios (70%–90% glycerin) we use for microwave breast tomography. The high level of attenuation is critical for suppressing unwanted multipath signals. This paper presents a full characterization of these liquids along with a discussion of their benefits and limitations in the context of microwave tomography. [ABSTRACT FROM AUTHOR]

This paper describes a technique that utilizes the osmotic properties of hydrogels to passively draw fluid through a membrane and pass it along to a microfluidic network for sensing purposes. This technique may enable non-invasive collection and manipulation of sweat for biosensing. To demonstrate the concept, thin hydrogel discs equilibrated in saline or glycerol were integrated with a microfluidic device. The hydrogel interfaces with a water-permeable membrane. The high concentration of solute in the hydrogel creates an osmotic pressure difference across the membrane, driving fluid flow through the membrane and into the device. The release of solute from the hydrogel autonomously pumps the fluid into an adjacent microfluidic channel. The flowrate of liquid drawn through the membrane is controlled by the osmotic pressure of the hydrogel and its interfacial contact area with the membrane. The flowrate gradually decreases over time as the continuous influx of withdrawn fluid dilutes the concentrated solute in the hydrogel. Initial testing has shown the device can pump accurate levels of glucose across the membrane and through a microchannel to a reservoir with a glucose sensor. Sensors and electrodes can be implemented in future microfluidic devices operating on these principles to test for other bioanalytes in sweat. [ABSTRACT FROM AUTHOR]

Single cell oils (SCO) can be a source of nutritionally valuable fatty acids and raw material in biodiesel production. Among the oleaginous yeasts, those which additionally generate carotenoid pigments are beneficially distinguished. Rhodotorula and Sporobolomyces strains were screened for the ability to grow and produce intracellular lipids in medium containing pure glycerol. In this paper, we verified that glycerol is unfavorable carbon source for a strain of S. salmonicolor and a good source of carbon for the growth and increases lipids content in the biomass of examined Rhodotorula yeast compared to glucose. The best volumetric efficiency of lipids biosynthesis (4.73 g L) in the medium with glycerol showed R. glutinis var. rubescens LOCKR13. In all investigated strains, oleic acid had the highest proportion of the total fatty acids. Nutritionally beneficial features were demonstrated by R. mucilaginosa, strain ATCC 66034 containing docosapentaenoic acid and reaching a high lipids biosynthesis efficiency (3.24 g L). Compared to glucose after incubation of R. aurantiaca, R. glutinis, R. gracilis and R. mucilaginosa strains with glycerol, the higher PUFA content per unit volume of medium was observed. [ABSTRACT FROM AUTHOR]

Value-added formamides were sustainably synthesized by the N-formylation of amines with glycerol derivatives (1,3-dihydroxyacetone, glyceraldehyde and glycolic acid) as the carbonyl source via in situ C–C bond cleavage catalyzed over zeolite 5A supported Cu-based catalysts. Introducing a second metal ZrIV ions can greatly increase the activity of the Cu/5A catalyst. Catalyst characterization results revealed that the introduction of ZrIV ions decreases the amount of surface acidic sites, in particular, medium–strong acidic sites and promotes the formation of ˙OOH radicals. Isotopic tracing experiments confirmed that all the carbon atoms in the carbonyl group of formamide products are indeed from glycerol derivatives. Combined electron paramagnetic resonance (EPR) spin-trapping, operando attenuated total reflection (ATR)-FTIR spectroscopy and control experiments revealed that the reaction of aniline and DHA with formanilide involves GA and HCOOH intermediates and ˙NHPh radicals via a ˙OH–˙OOH radical-relay mechanism. [ABSTRACT FROM AUTHOR]

Kaolinite possesses a structure with asymmetrically layered 1 : 1 dioctahedral aluminum silicate, and this structural property provides a useful platform for creating new cost-efficient functional materials that require noncentrosymmetric crystal packing. In this study, we prepared three covalently grafted kaolinites of propanediol (PD)/butanediol (BD)/glycerol (GL) by forming Al−O−C bonds between the OH groups of PD/BD/GL and the surface of kaolinite (K). Three covalently grafted kaolinites (K-PD, K-BD and K-GL) were characterized by X-ray diffraction, infrared spectroscopy, thermogravimetric analysis, scanning electron microscopy and microanalysis for C, H and N elements. The test of K-PD, K-BD and K-GL stirred with water at ambient conditions for 3 days demonstrated these hybrids showing extra high chemical stability to water. The dielectric spectra of three hybrids show two-step dielectric relaxation in the range of 1–107 Hz, and the P−E measurements revealed the existence of ferroelectricity at room temperature with the spontaneous polarization, the remanent polarization and the coercive field of ∼0.014 μC cm−2, ∼0.008 μC cm−2 and ∼0.426 kV cm−1 for K-PD, ∼0.017 μC cm−2, ∼0.011 μC cm−2 and ∼0.645 kV cm−1 for K-BD, and ∼0.018 μC cm−2, ∼0.011 μC cm−2 and ∼0.141 kV cm−1 for K-GL, respectively. [ABSTRACT FROM AUTHOR]

Arylamine-based push–pull molecules were successfully grafted onto various chiral diols (isomannide and isosorbide) or glycerol moieties, used as central biosourced cores, for the preparation of multichromophoric materials. Once their optical and electrochemical properties were investigated and rationalized, these new photoactive multimers were evaluated as potential donors in simple, air processed organic solar cells. [ABSTRACT FROM AUTHOR]

H6P2W18O62/γ-Al2O3 catalysts were prepared with different methods: (a) supercritical impregnation; (b) conventional wet impregnation. The obtained catalysts were characterized with XRD, SEM, N2 adsorption, NH3-TPD, Pyridine-IR, TG, ICP, and CHNS analyses. The results showed that supercritical CO2 was helpful in enhancing the dispersity of H6P2W18O62 supported on γ-Al2O3 and increased the surface area, pore volume and size, the total acid amount, and the proportion of Brønsted acid, and the formation of coke and the leaching of H6P2W18O62 were retarded. The main reason is because supercritical carbon dioxide has high solubility and diffusivity, which favors H6P2W18O62 dispersion and strengthens the interaction between H6P2W18O62 and hydroxyl on γ-Al2O3. The performances of two catalysts in glycerol dehydration were evaluated. The conversion of glycerol, selectivity and yield of acrolein, and catalytic stability were significantly enhanced on the H6P2W18O62/γ-Al2O3 catalyst prepared by supercritical impregnation because greater total acidity is conducive for improving the conversion of glycerol, while a higher ratio of Brønsted acid sites to total acidity is conducive for enhancing the acrolein selectivity. [ABSTRACT FROM AUTHOR]

In the present contribution, investigations on the chemical modification of thermosetting melamine formaldehyde resins by natural polyol compounds are presented. As representative agents soluble starch, sucrose, and glycerol were chosen to cover three different classes of polyols. The major aim was to use substances produced from natural bio-renewable feedstock that are available in large quantities and may serve as environmentally innocuous and bio-renewable substitutes for petro-chemically derived and potentially hazardous materials. Different reaction conditions lead to resins with varying technical performance. For soluble starch no reaction conditions could be found that allow the adoption of this substitute for the laminate industry due to insufficient technological performance. Sucrose and glycerol on the other hand yielded impregnation resins with suitable performance. Chemical linkage of the modifying agent into the chain propagation by poly-condensation however, was only found with glycerol. The covalent incorporation of glycerol in the network was observed with addition of glycerol at different stages during synthesis. The technological performance of the various modified thermosetting resins was assessed by determining flow viscosity, molar mass distribution, the storage stability, and in a second step laminating impregnated paper to particle boards and testing the resulting surfaces according to standardized quality tests. Spectroscopic evidence of chemical incorporation of glycerol was found by applying by 1H, 13C, 1H/13C HSQC, 1H/13C HMBC, and 1H DOSY methods. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011 [ABSTRACT FROM AUTHOR]

Both the energy shortage and pollution tend to slow down economic development and affect our daily lives. Some microorganisms not only can digest pollutants, but also can convert pollutant metabolites to triacylglycerol (TAG) that can be used to produce biodiesel. Here, we present results showing that the bacterium strain LDS5, a mutant of Rhodococcus sp. RHA1 (RHA1) generated in our lab, could grow well in chemithermomechanical pulping (CTMP) effluent, a type of paper mill wastewater, reduce chemical oxygen demand (CODCr) and biochemical oxygen demand (BOD5) significantly, and produce TAG. Our data suggest that this strain has the potential to be used in paper mill wastewater treatment as well as in the development of biodiesel using biomass from paper mills. [ABSTRACT FROM AUTHOR]

Maximising yield and minimising time are two top priorities for biotechnological industry. In this paper, we model the 1,3-PD uncoupled fed-batch fermentation process with a 10-dimensional nonlinear switched system. By taking both maximising 1,3-PD concentration and minimising the terminal time of fermentation as the objectives, we propose a multi-objective optimisation problem with the flow rates of glycerol and alkali, the switched times among four modes and the mode sequence as the decision variables. To solve the multi-objective optimisation problem, we use the convex weighted sum to transcribe the multi-objective optimisation problem into a sequence of single-objective optimisation problems. Then the time-scaling transformation, the binary relaxation approach and the exact penalty method are applied to solve these single-objective optimisation problems. The numerical results show that, by optimising the flow rates of glycerol and alkali, the switched times among four modes and the mode sequence, the optimum fed-batch time and the higher 1,3-PD concentration can be obtained. The obtained numerical results can provide reference for the actual fermentation experiment. [ABSTRACT FROM AUTHOR]

Inactivation of Bacillales and Clostridiales spores is of interest, since some cause food spoilage and human diseases. A recent publication (mSphere3: e00597‐1, 2018) reported that glycerol monolaurate (GML) in a non‐aqueous gel (GMLg) effectively killed spores of Bacillus subtilis, Bacillus cereus and Clostridioides difficile, and Bacillus anthracis spores to a lesser extent. We now show that (i) the B. subtilis spores prepared as in the prior work were impure; (ii) if spore viability was measured by diluting spores 1/10 in GMLg, serially diluting incubations 10‐fold and spotting aliquots on recovery plates, there was no colony formation from the 1/10 to 1/1000 dilutions due to GMLg carryover, although thorough ethanol washes of incubated spores eliminated this problem and (iii) GMLg did not kill highly purified spores of B. subtilis, B. cereus, Bacillus megaterium and C. difficile in 3–20 h in the conditions used in the recent publication. GMLg also gave no killing of crude B. subtilis spores prepared as in the recent publication in 5 h but gave ~1·5 log killing at 24 h. Thus, GMLg does not appear to be an effective sporicide, although the gel likely inhibits spore germination and could kill spores somewhat upon long incubations. Significance and Impact of the Study: Given potential deleterious effects of spores of Bacillales and Clostridiales, there is an ongoing interest in new ways of spore killing. A recent paper (mSphere3: e00597‐1, 2018) reported that glycerol monolaurate (GML) in a non‐aqueous gel (GMLg) effectively killed spores of many species. We now find that (i) the Bacillus subtilis spores prepared as in the previous report were impure and (ii) GMLg gave no killing of purified spores of Bacillales and Clostridiales species in ≤5 h under the published conditions. Thus, GMLg is not an effective sporicide, though may prevent spore germination or kill germinated spores. [ABSTRACT FROM AUTHOR]

In this paper, we consider time-delay optimal control of 1,3-propan-ediol (1,3-PD) fed-batch production involving multiple feeds. First, we propose a nonlinear time-delay system involving feeds of glycerol and alkali to formulate the production process. Then, taking the feeding rates of glycerol and alkali as well as the terminal time of process as the controls, we present a time-delay optimal control model subject to control and state constraints to maximize 1,3-PD productivity. By a time-scaling transformation, we convert the optimal control problem into an equivalent problem with fixed terminal time. Furthermore, by applying control parameterization and constraint transcription techniques, we approximate the equivalent problem by a sequence of finite-dimensional optimization problems. An improved particle swarm optimization algorithm is developed to solve the resulting optimization problems. Finally, numerical results show that 1,3-PD productivity increases considerably using the obtained optimal control strategy. [ABSTRACT FROM AUTHOR]

In this paper, we consider a multistage feedback control strategy for the production of 1,3-propanediol(1,3-PD) in microbial fermentation. The feedback control strategy is widely used in industry, and to the best of our knowledge, this is the first time it is applied to 1,3-PD. The feedback control law is assumed to be linear of the concentrations of biomass and glycerol, and the coefficients in the controller are continuous. A multistage feedback control law is obtained by using the control parameterization method on the coefficient functions. Then, the optimal control problem can be transformed into an optimal parameter selection problem. The time horizon is partitioned adaptively. The corresponding gradients are derived, and finally, our numerical results indicate that the strategy is flexible and efficient. [ABSTRACT FROM AUTHOR]

This paper deals with an original and non-biocidal chemical treatment consisting of a vacuum/pressure impregnation step of beech wood with a water-borne mixture made from heat-activated condensation of succinic anhydride (SA) and glycerol (G). Chemical structures of adducts were established using matrix-assisted laser desorption ionization time-of-flight mass spectroscopy (MALDI-TOF) investigations. Beech wood was impregnated and cured in order to induce in situ polymerization of glycerol/succinic adducts (GSA) in the cell walls, leading to the formation of polyglycerol succinate (PGS) polyester. Various treatment conditions were investigated depending on the duration (6–72 h) and curing temperature (103–160°C). Weight percent gains (WPGs) ranging between 40 and 60% were obtained. Attenuated total reflectance-middle infrared spectroscopy (ATR-MIR) and carbon-13 nuclear magnetic resonance (13C-NMR) spectroscopy confirmed polyester formation. A curing temperature of 160°C was found to be the best condition to totally avoid polymer leaching, and brought the anti-swelling efficiency (ASE) up to 64%. Decay resistance of PGS-treated wood against Trametes versicolor and Coniophora puteana was also strongly temperature and time dependent: performances fit with the EN113 standard requirements if a curing temperature of 160°C was applied. [ABSTRACT FROM AUTHOR]

Biopolymers are sustainable materials derived from renewable sources that have relevant and industrially attractive properties such as biodegradability, biocompatibility and antimicrobial effect. Thus, these were the target of several experimental studies, widely published in the literature and used in our daily lives. This paper presents a preliminary investigation on the polyesterification of a malic acid/glycerol mixture in order to obtain the poly(glycerol-co-malic acid) to be evaluated as a bioadhesive. For this, different reaction conditions were evaluated by varying the concentrations of malic acid, glycerol and zinc chloride(II) as catalyst, carried out according to the central composite rotatable design. The polymerizations were monitored by acidity index, hydroxamic acid test and conversion rate and the obtained materials characterized by FTIR. Poly(glycerol-co-malic acid) was obtained in yields of 38 to 68% which show that such method is promising for obtaining this new biopolymer aimed as bioadhesive. [ABSTRACT FROM AUTHOR]

In this paper, the effect of glycerol solution on the behaviour of a sediment of a clay soil and its treatment was investigated through a programme of experimental tests. Laboratory tests were conducted to study settlement of the clay soil in water and in solutions of glycerol with different concentrations. Also, treatment of the sediments deposited in water and solutions of glycerol was investigated by adding 5%, 8% and 10% cement to these sediments. Atterberg limits, compaction and unconfined compression tests were conducted on treated and untreated sediments. Comparison of the results showed that the behaviour of the sediments that were deposited in water and in different solutions of glycerol are not the same. The results also indicted that the cement is effective in the treatment of sediments deposited in solutions of glycerol and for a given percent of cement and curing time, the degree of treatment is dependent on the percent of glycerol in the solution. Increasing the concentration of glycerol decreases the strength of the sediment with time. Based on SEM analysis, it was found that the fabric of the soil deposited in water is different from those of the soils deposited in solutions of glycerol. [ABSTRACT FROM AUTHOR]

The improvement of the combustion process in gasoline spark engines has been a painstaking task focused on developing chemical compounds. These ones have to be capable of bettering the engine performance and meeting standards set by environmental and health regulations aimed at reducing the emission of hazardous pollutants. Among the molecules synthesized for reaching these goals, oxygenating agents have been used to increase the octane number and make more efficient the combustion reaction by reducing the emissions of CO, polyaromatic hydrocarbons (PAHs), and particulate matter. As a result of this quest, MTBE has been used as a solution, but in recent years, negative effects of its use polluting water bodies and, as a consequence, the human health, have proven the opposite. For this reason, alternative oxygenating compounds to MTBE such as alcohols, ethers, and esters are being studied. According to the aforementioned, in the present paper, alternative oxygenating agents belonging to glycerol acetates (GAs) were synthesized from crude glycerol (CG) obtained as a biodiesel by-product and conditioned as starting material to perform esterification reactions with acetic acid or acetic anhydride. In order to assess the performance of these compounds as octane index enhancers, measurements using the same composition of ethanol, MTBE and the as-obtained GAs, in reference gasoline, were made, yielding comparable results that encourage the potential use of acetins as a replacement of MTBE. [ABSTRACT FROM AUTHOR]

In the modern world, the environmental problem is one of the most important. The amount of plastic waste increases sharply every year. The recycling of such waste is complicated by a large number of types of plastic and the difference in their structure. Polyethylene terephthalate (PET) is widely used in everyday life, as well as polyethylene and polypropylene, but in contrast to them, PET contains esters groups. Thus, this plastic can be recycled with various polar reagents, such as water, alcohols, glycols, and so on. This paper describes a method for the depolymerization of PET using the main byproduct of biodiesel production-crude glycerol. waste PET and crude glycerol, a raw material containing potassium salts of fatty acids, which were formed during alkaline catalysis of the biodiesel production reaction, were used as raw materials. Complete PET conversion can be achieved in 90 minutes at 190- 195° C and at atmospheric pressure. As a result of the recycling of PET and biodiesel wastes, valuable products such as the potassium salt of terephthalic acid, its esters with glycerol and glycol as well as fatty acids glycol esters can be isolated. [ABSTRACT FROM AUTHOR]

This work reports a facile synthesis of linear long chain aliphatic polyester, namely poly(glycerol pimelate) polyester (PGP) characterised by Fourier transform infrared spectroscopy (FTIR) and Nuclear magnetic resonance spectroscopy (1H and 13C NMR). Thermal response of PGP was studied using Thermo gravimetric analysis (TGA) and Differential scanning calorimetry (DSC). Glass transition temperature (Tg) of 117 °C and thermal stability up to 290 °C was noticed from DSC and TGA analysis. As a potential application, the capability and extent of retarding the mild steel dissolution in 0.5 M H2SO4 medium rendered by the synthesised PGP was analysed by electrochemical and non-electrochemical methods. Weight loss measurements carried out at room temperature showed decreased corrosion rate with concentration (10, 50, 100, 500 and 1000 ppm) resulting in a moderate inhibition efficiency of 61.60% at 1000 ppm. Decreased inhibition efficiency was noticed on increasing the temperature from 303 K-333K. Various parameters were derived to understand the mode of adsorption. Increased charge transfer resistance (Rct) from electrochemical impedance method (EIS) and decreased corrosion current density (Icorr) from potentiodynamic polarisation technique on increasing the concentration was in good agreement with weight loss measurements. Suppression of metal dissolution by the formation of film on the metal surface was additionally supported by X-ray diffraction studies (XRD), scanning electron microscopy (SEM) and Energy dispersive spectroscopy (EDS) followed by Atomic force microscopy (AFM). X-ray photoelectron spectroscopy (XPS) revealed the same with a detailed insight of adsorption of inhibitor on the metal surface. This paper explores the following highlights: Low cost and facile synthesis of polyester. Controversy result of moderate inhibition efficiency has been justified. Potentiodynamic polarisation studies revealed mixed type of inhibition. Morphological studies like XPS predicted detailed insight of adsorption. [ABSTRACT FROM AUTHOR]

2,3-Butanediol (2,3-BD) has great potential for diverse industries, including chemical, cosmetics, agriculture, and pharmaceutical areas. However, its industrial production and usage are limited by the fairly high cost of its petro-based production. Several bio-based 2,3-BD production processes have been developed and their economic advantages over petro-based production process have been reported. In particular, many 2,3-BD-producing microorganisms including bacteria and yeast have been isolated and metabolically engineered for efficient production of 2,3-BD. In addition, several fermentation processes have been tested using feedstocks such as starch, sugar, glycerol, and even lignocellulose as raw materials. Since separation and purification of 2,3-BD from fermentation broth account for the majority of its production cost, cost-effective processes have been simultaneously developed. The construction of a demonstration plant that can annually produce around 300 tons of 2,3-BD is scheduled to be mechanically completed in Korea in 2019. In this paper, core technologies for bio-based 2,3-BD production are reviewed and their potentials for use in the commercial sector are discussed. [ABSTRACT FROM AUTHOR]

Glycerin is a promising liquid dielectric for pulsed power systems because of its high storage energy density and high resistivity. In order to further improve the energy storage density of glycerin, its breakdown characteristics should be investigated. In this paper, experiments are carried out to study the decline of the breakdown voltage of glycerin in a repetitive pulsed pulse forming line (PFL) in both the single pulse mode and the repetitive pulsed mode. It is shown that the breakdown voltage of the glycerin PFL is reduced by about 35% after 100 pulses in 10 s. The bubbles in glycerin are suspected to be an important factor affecting the breakdown characteristics. By using a high-speed camera, the deformation of bubbles (especially the height) is observed in the experiments and the deformation of bubbles is cumulative after multiple pulses. Experiments confirm that the bubbles' height is influenced by factors including the electric field, pressure, and temperature. These experimental results demonstrate an important process of the liquid breakdown in the repetitive pulsed mode, which will be helpful to improve the breakdown characteristics of liquid dielectrics. [ABSTRACT FROM AUTHOR]

Selective oxidation is of key importance in the synthesis of chemical intermediates. For many years a number of oxides and supported metal catalysts have been used. The key questions involved in the design of selective oxidation catalysts are discussed in the initial part of this paper. One of the most exciting recent developments in the field of selective oxidation has been the discovery that supported gold catalysts are active. The second part of the paper discusses Au/C catalysts, which are shown to be particularly versatile for oxidation reactions. Four examples of selective oxidation are described using molecular oxygen as oxidant: (a) selective oxidation of glycerol to glycerate in the presence of base; (b) the oxidation of cyclohexane to cyclohexanol and cyclohexanane in the presence of a radical initiator; (c) the oxidation of hydrogen to hydrogen peroxide, and (d) the oxidation of benzyl alcohol to benzaldehyde under solvent free conditions. In contrast, the Au/C catalysts are not active for oxidation of carbon monoxide at ambient temperature. These examples demonstrate that there exists a rich potential for Au/C as a selective oxidation catalyst and that research efforts should now be focussed on selective oxidation using supported gold catalysts. [ABSTRACT FROM AUTHOR]

1H spin-lattice relaxation rates R1 = 1/T1 have been measured for partly deuterated glycerol-h5 diluted in fully deuterated glycerol-h0 for progressively lower concentrations of glycerol-h5. By means of the field cycling (FC) technique relaxation dispersion data, R1(ω), have been collected for several temperatures in the frequency range of 10 kHz-20 MHz. In order to disclose the spectral shape of the intra- and intermolecular relaxation, extrapolation of the relaxation data to the zero concentration limit has been performed. The paper confirms that the low frequency excess contribution to the total relaxation rate R1(ω) previously reported for several liquids is of intermolecular origin and reflects translational motion, whereas the high-frequency part is attributed to molecular rotation. Thus, intra- and intermolecular relaxation contributions are spectrally separated. The intermolecular relaxation itself contains also a contribution from rotational motion, which is due to non-central positions of the interacting nuclei in the molecule. This eccentricity effect is quantitatively reproduced by treating the intermolecular spectral density as a sum of translational-like (described by the free diffusion model) and rotational-like contributions (described by a Cole-Davidson function). Applying frequency-temperature superposition master curves as well as individual relaxation dispersion data, R1(ω), are analyzed. It is demonstrated that, in spite of the rotational influence, the translational diffusion coefficients, D(T), can be extracted from the 1H relaxation dispersion which gives 1H NMR relaxometry the potential to become a routine technique determining the diffusion coefficient in liquids. [ABSTRACT FROM AUTHOR]

BSTRACT Whey protein concentrates with ˜80% protein (WPC-80) plasticized with 0.64 M glycerol or sucrose, or with 0.34 or 0.64 M sorbitol or polyethylene glycol (PEG) 200, produced flexible films. WPC-80 with hydrolyzed lactose required addition of less sucrose to produce flexible films. WPC-80 films formed as coatings on paperboard gave a grease barrier comparable to WPI film-coatings. Long-term ambient storage of WPC-80 coated paperboard indicated that the use of sucrose as plasticizer imparted good grease resistance and minimized plasticizer migration. [ABSTRACT FROM AUTHOR]

With the development of the biodiesel industry, the annual production of the byproduct glycerol has increased to a level of nearly millions of tons. Efficient and clean utilization of glycerol is thus urgent and profitable. Direct glycerol fuel cells (DGFCs) capable of selective oxidation of glycerol and co-generation of electricity and high-value added chemicals seem to be the most compelling technique. Unfortunately, selective and durable electrocatalysts for fabricating DGFCs are still not available so far. Herein, ternary Pt–Pd–Ag alloy nanowires (NWs) are designed and synthesized under the direction of the d-band theory. The resulting Pd–Pt–Ag NWs exhibit significant activity towards the glycerol electro-oxidation reaction (GOR) and oxygen reduction reaction (ORR) in an alkaline medium, which outperforms the bimetallic Pt–Ag alloy NWs and the commercial Pt/C benchmark. Moreover, a homemade DGFC based on bifunctional Pd–Pt–Ag NW anode and cathode can achieve a peak power density of 13.7 mW cm−2 under ambient conditions (∼50% enhancement compared to the DGFC based on the Pt/C benchmark) and deliver a record voltage of 1.13 V ever reported in alcohol-feeding fuel cells. Besides the electricity profits, the DGFC concurrently generates value-added formate as a selective product of glycerol oxidization. [ABSTRACT FROM AUTHOR]

The fabrication of a flexible and highly sensitive strain sensor with the incorporation of glycerol, by vapor phase hybridization, improves the physical properties of ternary composite elastomers consisting of thermoplastic polyurethane (TPU), graphene oxide, polyethylene glycol and silica (TPU-GPS). The addition of glycerol to the TPU-GPS composite improves the dispersion of graphene oxide and the mechanical, electrical, thermal, and strain sensing sensitivity properties of the graphene oxide-based strain sensor. A certain amount of glycerol in the composite blend is modified to achieve excellent strain sensor performance. The results revealed 65% strain increase compared to the TPU-GPS strain sensor on its elongation at break. The presence of glycerol in the polymer matrix is confirmed by field-emission scanning electron microscopy (FE-SEM), attenuated total reflectance Fourier-transform infrared spectroscopy (ATR-FTIR), X-ray diffraction (XRD) and differential scanning calorimetry (DSC) characterization studies. More impressively, TPU-GPS with 3 wt% of glycerol (TPU-GPS-3GLY) demonstrates outstanding sensitivity (gauge factor = 20) that is two times higher than that of the TPU-GPS pristine composite. Furthermore, the sensor can monitor a small-scale strain up to <1% and respond for up to 20 000 cycles with extraordinary stability and repeatability. Owing to the uniform dispersion of graphene oxide in the polymer matrix as a result of glycerol introduction, the composite represents a useful development in the strain sensor application. [ABSTRACT FROM AUTHOR]

Three novel imidazole-based two-photon absorption compounds bearing different organic cations (1PIPy, 2PIQu, and 3PIIm) were facilely synthesized and fully characterized by 1H NMR, 13C NMR, FT-IR, and HRMS. The linear and nonlinear photophysical properties of the target compounds were systematically investigated in various solvents, supplemented with the density functional theory calculations to shed light on their structure–property relationships. The maximum two-photon action cross-sections (Φ × δmax) were determined to be 22.4–98.2 (CH2Cl2), 9.6–41.3 (DMF), and 3.9–11.8 (H2O) GM. It is found that 3PIIm shows significant viscosity sensitivity with a sharp 27-fold increase in fluorescence intensity. Its fluorescence intensity also exhibits a linear relationship with the viscosity of the media in a logarithmic plot. The Φ × δmax value of 3PIIm in highly viscous glycerol was found to be 107.5 GM. Cytotoxicity tests indicate that these compounds have relatively low cytotoxicity. All the target compounds were successfully characterized by one- and two-photon fluorescence imaging in living cells. The colocalization experiments reveal that 1PIPy and 3PIIm are specially located in the endoplasmic reticulum (ER) with the Pearson's coefficients above 0.90. 3PIIm can also monitor the fluctuation of ER viscosity during etoposide-induced apoptosis. [ABSTRACT FROM AUTHOR]

Herein, we report a well-defined pincer manganese complex supported by PNP ligands for the conversion of glycerol to sodium lactate with dihydrogen liberation. Sodium lactate could be obtained in 96% yield with 96% selectivity under mild reaction conditions, with the Mn-3 complex as the catalyst. In this transformation, catalyst loadings even as low as 0.025 mol% could also result in high reactivity and excellent selectivity (up to 98%) at 180 °C in 36 hours. Mechanistic studies demonstrated that the manganese catalyst was mainly responsible for glycerol dehydrogenation, while the amount of sodium hydroxide had a crucial effect on the subsequent Cannizzaro reaction. In addition, the catalytically active species in the reaction were investigated by using in situ31P NMR spectroscopy. This catalytic system provides a green, efficient, and atom-economical approach for upgrading biodiesel waste into high-value chemicals. [ABSTRACT FROM AUTHOR]

Glyceric acid (GA), a glycerol derivative, can be used as a versatile platform molecule to produce value-added chemicals. Succinic acid (SA) is a very important bio-based molecule that acts as a fine chemical and is used in biodegradable polymer synthesis. It has been shown earlier that GA can be effectively converted to the platform chemical 3-iodopropionic acid (3-IPA) with a RhCl3/HI catalyst system. In this work, we first explored the production of SA from 3-IPA by carbonylation. With RhCl3 as the catalyst and acetic acid (AA) and water as the solvent, as high as 78% yield of SA can be achieved. Considering the similarity of the catalysts used in two steps, we then further probed the one-step synthesis of SA directly from GA. Under optimized reaction conditions, 71% yield of SA can be obtained directly from GA by reductive carbonylation with RhCl3 and I2 as the catalyst under H2 and CO atmospheres. This is the first report of the direct conversion of GA to SA, which provides a novel method for glycerol valorization. [ABSTRACT FROM AUTHOR]

In this paper, we report the study of the free-solvent nucleophilic addition of alcohols and glycerol to acrylic compounds, in the presence of catalytic bases. With acrylates, Michael addition and transesterification are in competition: only the PTC reaction with t-butyl acrylate gave trifunctionalized glycerol. With acrylonitrile, the cyanoethylation of glycerol varies with catalysts, temperature, time of reactions and amounts of acrylonitrile. Mono functionalisation of glycerol can be obtained in 28% yield. The optimization of the free-solvent Michael addition of glycerol to acrylonitrile (3.4 equiv., 4 mol% NaOH, 5 h) leads to TCEG (tricyanoethylglycerol, 88% yield, 99% purity) without HCl neutralisation, chlorinated solvents or purification (chromatography or distillation). TCEG can be used as a prochiral core of G0.5 dendrimers. [ABSTRACT FROM AUTHOR]

Nano-sized particles of monoclinic-LaVO4 were prepared in a short reaction time of 30 minutes by employing a microwave assisted hydrothermal synthesis in the presence of glycerol, which was used both as a solvent and structure-directing agent. The tetragonal-LaVO4 is known to show strong luminescence properties when doped with Ln3+, whereas the monoclinic-LaVO4 is usually considered not suitable for luminescence and therefore luminescence properties of monoclinic-LaVO4 doped with Ln3+ ions are seldom investigated. Due to the scarce amount of research on the topic of luminescence of Ln3+ doped monoclinic-LaVO4 in this paper a detailed study of solid state luminescence properties, including quantum yields, of nano-sized monoclinic-LaVO4 doped with different molar percentages of Eu3+ is presented. It was observed that the 12.5%Eu3+ doped sample showed the strongest luminescence properties. Additionally a study of the influence of different rare-earth ions (Y3+, Gd3+, Lu3+) co-doped into the particles was performed in order to explore the potential of increasing the luminescence of these materials. Furthermore stable colloidal suspensions of the Eu3+ doped monoclinic-LaVO4 nanoparticles showing strong red emission could be obtained. [ABSTRACT FROM AUTHOR]

The inevitably low value of bioglycerol has led to extensive investigations on glycerol conversion to value-added chemicals. This review focuses on the industrially important catalytic esterification of glycerol with oleic acid attributable to its high commercial value. Conventionally, the catalytic esterification of long-chain fatty acids with glycerol is operated at extreme operating conditions (homogeneous acid catalyst, high temperature, and intensive vacuum system). Because of these, rational design of reliable solid acid catalysts for water-sensitive esterification process is needed in order to enhance existing process condition. Up until now, the recent development of efficient and environmentally benign catalysts for esterification of glycerol with oleic acid has not been captured in any review. Therefore, the current literatures of catalytic esterification of glycerol with oleic acid and their affecting parameters are primarily discussed in this review. This review has shown that the hydrophobicity surface of catalysts is vital to boost up the reaction activity of polar glycerol and immiscible phase behavior of reactants. In addition, the concluding remarks for catalyst selectivity of glycerol monooleate, dioleate, and trioleate synthesis are presented. The paper also highlights the research gaps and future direction of this important research field. [ABSTRACT FROM AUTHOR]

• Hydrogen production from glycerol was carried out by electrochemical reforming. • Glycerol, which was formed as a by-product in biodiesel production by transesterification method, was used. • Effect of membrane type and electrode material were examined. • Membrane electrode assembly was created and used in originally designed cubic electrolysis cell. • The impact and role of the shape and type of the current collector were determined. In this paper, hydrogen production from glycerol have been investigated in a cubic electrolysis cell with/without membrane and in the system with membrane electrode assembly (MEA). Membrane and electrode effects on hydrogen production were examined in the electrolysis cell originally designed and manufactured. A constant current density value of about 10 mA/cm2 was recorded in the electrochemical reforming of glycerol in acidic electrolyte conditions in the system using Nafion 117 membrane at room temperature under 2 V constant potential. The highest current density value was reached in the case where the oxidation of glycerol at the anode occurred on the Zn electrode and the hydrogen evolution reaction at the cathode occurred on the Pt electrode. The current density value increased by 24 % using a Pt electrode instead of Zn at the cathode. According to the results of the cathode peak area in the gas chromatography analysis, the highest hydrogen formation was recorded under these conditions. To create MEA, 5.7 mg/cm2 10 % Pt/C (0.57 mg/cm2 Pt) and 5 mg/cm2 Zn were loaded for the cathode and anode respectively. A nozzle-type current collector made of copper material was selected among the current collectors of different geometries and materials used in the electrochemical reforming of glycerol. A constant current density value of approximate 500 mA/cm2 was achieved under the specified conditions and with diverse system improvements. [ABSTRACT FROM AUTHOR]

Biodiesel has emerged as a promising alternative to conventional diesel fuel, offering potential reductions in greenhouse gas (CO2) emissions. However, its use in diesel engines results in higher levels of nitrogen oxides (NOx). This study investigates emulsification techniques for reducing NOx emissions from biodiesel combustion. Two techniques, glycerin and water emulsification, are examined. Approximately 10 vol. % of crude glycerin is produced during biodiesel manufacturing as a waste or by‐product. The study attempts on‐site purification of crude glycerin, which is then used as a phase for glycerin‐biodiesel emulsions. These emulsions are compared to water emulsions in terms of emulsion stability, mean particle droplet size, microscopic fuel structure, and fuel properties. In addition, engine performance and emissions are evaluated using a small direct injection (DI) diesel engine, with both water and glycerin emulsion fuels. Results show that both emulsion fuels significantly reduce smoke emissions and further mitigate NOx emissions from biodiesel combustion. With 10% glycerin and water emulsions, smoke emissions were reduced by over 50% compared to pure biodiesel, and NOx emissions decreased by more than 15%. Emulsification techniques in the biodiesel industry could offer a viable solution for reducing both smoke and NOx emissions. Employing glycerin emulsification not only decreases NOx emissions but also transforms crude glycerin into a value‐added resource. Otherwise, disposal of crude glycerin could pose significant challenges for small and remote biodiesel producers due to cost constraints. [ABSTRACT FROM AUTHOR]

Carbon-based nanodots have garnered recent interest for their simple synthesis and versatile utility, ranging from biomedical to (opto) electronic applications, evolving into a tunable and biocompatible material. Here, for the first time, a biochar (lotus leaf) derived carbon nanodots was synthesized through hydrothermal carbonization. The synthesized hollow spherical biochar was engineered via functionalization by grafting –SO3H active sites. The attained catalyst was broadly analyzed by XRD, FTIR, TGA, BET, SEM–EDX, TEM, and XPS analysis after which it was applied for the acetalization reaction of crude glycerol (a biodiesel by-product) to form solketal, a potential fuel additive to valorize the large waste stream generated from biodiesel industry. Employing the RSM-CCD methodology, the experimental matrix was executed, and subsequent data were scrutinized through multiple regressions to model a quadratic equation. Under specific reaction parameters—a reaction duration of 14 min, a molar ratio of 7.5:1, and a catalyst loading of 5.7 wt.%, maximum solketal yield (95.7%) was attained through the ultrasonication method. Finally, to conclude, life cycle cost analysis (LCCA) for solketal production was studied here which determined the overall cost of solketal production per kilogram to be 0.719 USD ($), indicating high commercial applicability. [ABSTRACT FROM AUTHOR]

Soft tissue engineering has focused on green, solvent-free biopolymers with rubber-like characteristics. One of the well-known elastomeric polyesters is polyglycerol sebacate (PGS). The present investigation involves the synthesis of a novel biopolymer composed of PGS-co-poly(ε-caprolactone) (PCL) copolymer, alongside hydroxyapatite (HA) using bovine bone. These synthesized materials were utilized to build scaffolds using 18–22 kV electrospinning. By in situ polymerization, PGS-co-PCL/HA nanocomposites with 5% and 10% hydroxyapatite nanoparticles were developed. Various analysis such as FTIR, TGA, SEM, and DSC were utilized to examine the prepared samples. Introducing 10% HA to the PGS-co-PCL copolymer blends boosted nanocomposite mechanical strength by 300%. Meanwhile, PGS-co-PCL-based samples and their nanocomposites demonstrated promising biocompatibility and antibacterial characteristics. Biodegradability experiments revealed that at pH 7, PGS-co-PCL-HA10% was degraded by 45% within 30 days, whereas at pH 11, degradation accelerated to 65%. This study's findings provide a novel approach for soft tissue engineers to construct effective scaffolds with great biocompatibility and enhanced mechanical properties by combining PGS with co-PCL and adding HA nanoparticles. [ABSTRACT FROM AUTHOR]

The electrochemical conversion of glycerol into high-value chemicals through the selective glycerol oxidation reaction (GOR) holds importance in utilizing the surplus platform chemical component of glycerol. Nevertheless, it is still very limited in producing three-carbon chain (C3) chemicals, especially glyceric acid/glycerate, through the direct oxidation of its primary hydroxyl group. Herein, Pd microstructure electrodeposited on the Ni foam support (Pd/NF) is designed and fabricated to achieve a highly efficient GOR, exhibiting a superior current density of ca. 120 mA cm−2 at 0.8 V vs. reversible hydrogen electrode (RHE), and high selectivity of glycerate at ca. 70%. The Faradaic efficiency of C3 chemicals from GOR can still be maintained at ca. 80% after 20 continuous electrolysis runs, and the conversion rate of glycerol can reach 95% after 10-h electrolysis. It is also clarified that the dual-component interfaces constructed by the adjacent Pd and Ni sites are responsible for this highly efficient GOR. Specifically, Ni sites can effectively strengthen the generative capacity of the active adsorbed hydroxyl (OHad) species, which can steadily immigrate to the Pd sites, so that the surface adsorbed glycerol species are quickly oxidized into C3 chemicals, rather than breaking the C–C bond of glycerol; thus, neither form the C2/C1 species. This study may yield fresh perspectives on the electrocatalytic conversion of glycerol into high-value C3 chemicals, such as glyceric acid/glycerate. [ABSTRACT FROM AUTHOR]

The quest for better nutritious foods has encouraged novel scientific investigations to find trans-fat reduction methods. This research proposes an innovative approach for the production of healthier trans-fat-free margarine from palm oil by the use of dielectric barrier discharge (DBD) plasma technology with glycerol serving as the principal source of hydrogen. The effectiveness of DBD plasma in hydrogenating palm olein was investigated. By employing a methodical series of experiments and thorough analytical approaches, examination of the saturated fatty acid conversion experienced its iodine value (IV) reduction from 67.16 ± 0.70 to 31.61 ± 1.10 under the optimal process parameters of 1 L min−1 He flow rate, 35 W plasma discharge power, 10 mm gap size, ambient initial temperature, and 12 h reaction time with solid texture. According to the method for producing trans-fat-free margarine in the absence of a catalyst and H2 gas, the hydrogenation rate of the prepared mixture of palm olein-glycerol was remarkably improved; the trans-fat content in the produced product was zero; the efficacy of incorporating cis- and trans-isomerization was lowered, and the method has a promising industrial application prospect. [ABSTRACT FROM AUTHOR]

This document is a compilation of contributions to a special issue on catalysts published in the journal Catalysts. The contributions cover various topics related to catalysis, including the hydrodeoxygenation of lignin-derived compounds, the synthesis of bifunctional catalysts, transfer hydrogenation of biomass-like compounds, and the development of multifunctional catalytic systems. Each contribution presents research findings and discusses the implications and potential applications of the respective catalysts. The authors express their gratitude to the editorial team and reviewers for their support and contributions. [Extracted from the article]

Hot air, water, and glycerol were studied as foaming mediums for the production of ETPU to evaluate their influence on the behavior of the foam and compare the optimal particles for each of the foaming temperatures selected. The results showed that the times of water foaming and glycerol foaming were shorter by about 2/3 than with hot-air foaming. The best foaming temperatures for hot-air foaming, glycerol foaming, and water foaming are 110–115 °C, 75 °C, and 90 °C, respectively. The particles of glycerol foam have a matte appearance and their gloss is not very good. However, the particles in hot-air foaming are light, and the gloss is very satisfactory. The gloss of the surface of water-foaming particles is dim. At the same time, there is a faint matte appearance. Particles made with glycerol foaming and water foaming are more even than those made with hot-air foaming. The density of foaming materials from glycerol foaming, hot-air foaming, and water foaming are raised accordingly, while the hardness of foaming materials from glycerol foaming, water foaming, and hot-air foaming are successively increased. [ABSTRACT FROM AUTHOR]

The discharge of dye waste by industries has caused environmental impacts on water properties, aquatic species, and human life. The production of eco-friendly materials for dye removal from wastewater has gained increasing interest, particularly through adsorption, as it is an efficient method for removing pollutants. However, the selectivity and limited adsorption capacity of materials for simultaneously adsorbing cationic and anionic dyes make it challenging to address the prevailing dye effluent issue. In this work, a poly(glycerol citrate) polyester was prepared without a solvent, using microwave heating, and was combined with cetyltrimethylammonium bromide (CTAB) to modulate the simultaneous adsorption of cationic (Rhodamine B, RB) and anionic dyes (acid blue 113, AB and acid red 27, AR). The formation of the polyester was successfully confirmed by ATR-FTIR and the thermal properties were evaluated by TGA and DCS. In the presence of CTAB 5 mM, the material removes almost 100% of the dyes, reaching the kinetics equilibrium in 30 min following the Pseudo-second order model. Additionally, dye adsorption on the polyester in the presence of CTAB was described by the Freundlich isotherm model, indicating a heterogeneous polyester surface that promotes a multi-layer adsorption driven by electrostatic interaction and hydrogen bonds. The material showed an adsorption capacity of 73.7 ± 3.2, 82.1 ± 4.4, and 21.2 ± 0.6 mg/g for RB, AB, and AR, respectively. Our results provide evidence that the poly(glycerol citrate)/CTAB has a higher potential for application in wastewater treatment to remove both anionic and cationic dyes. [ABSTRACT FROM AUTHOR]

Currently, petroleum-derived plastics are widely used despite the disadvantage of their long degradation time. Natural polymers, however, can be used as alternatives to overcome this obstacle, particularly cornstarch. The tensile properties of cornstarch films can be improved by adding plant-derived nanofibers. Sisal (Agave sisalana), a very common low-cost species in Brazil, can be used to obtain plant nanofibers. The goal of this study was to obtain sisal nanofibers using low concentrations of sulfuric acid to produce thermoplastic starch nanocomposite films. The films were produced by a casting technique using commercial corn starch, glycerol, and sisal nanofibers, accomplished by acid hydrolysis. The effects of glycerol and sisal nanofiber content on the tensile mechanical properties of the nanocomposites were investigated. Transmission electron microscopy findings demonstrated that the lowest concentration of sulfuric acid produced fibers with nanometric dimensions related to the concentrations used. X-ray diffraction revealed that the untreated fibers and fibers subjected to acid hydrolysis exhibited a crystallinity index of 61.06 and 84.44%, respectively. When the glycerol and nanofiber contents were 28 and 1%, respectively, the tensile stress and elongation were 8.02 MPa and 3.4%. In general, nanocomposites reinforced with sisal nanofibers showed lower tensile stress and higher elongation than matrices without nanofibers did. These results were attributed to the inefficient dispersion of the nanofibers in the polymer matrix. Our findings demonstrate the potential of corn starch nanocomposite films in the packaging industry. [ABSTRACT FROM AUTHOR]