Infrared Spectroscopy of Bilberry Extract Water-in-Oil Emulsions: Sensing the Water-Oil Interface

Kiefer, Johannes; Frank, Kerstin; Zehentbauer, Florian M.; Schuchmann, Heike P.

doi:10.3390/bios6020013

Cited by 25 publications

(24 citation statements)

References 24 publications

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“…This supports that these OH groups are not participating in any intermolecular interaction. The band at 3417 cm −1 is close to the wavenumber observed for asymmetrically hydrogen‐bonded water molecules ,. This strongly corroborates our hypothesis that each OH group in C 2 OHmimPic is involved in two hydrogen bonding interactions.…”

Section: Resultssupporting

confidence: 88%

Clusters of the Ionic Liquid 1‐Hydroxyethyl‐3‐methylimidazolium Picrate: From Theoretical Prediction in the Gas Phase to Experimental Evidence in the Solid State

2018

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Interonic interactions determine the macroscopic properties of ionic liquids (ILs). Hence, unravelling the relationships between the microscopic and macroscopic scales is key for rational design. Combining density functional theory (DFT) calculations of isolated ion pairs and vibrational spectroscopy of the condensed phase (fluid or solid) has become a very common approach. In the present work, we make a step towards understanding how the physicochemical effects in small gas phase clusters of a hydroxyl functionalized imidazolium-picrate IL relate with the molecular structure and interactions of the corresponding solid material taking 1-hydroxyethyl-3-methylimidazolium picrate, C OHmimPic, as an example. In the isolated ion pair, strong alkyl-OH⋅⋅⋅Pic hydrogen bonding interactions are found rather than the commonly observed hydrogen bonding interactions at the slightly acidic C(2)-H site of the imidazolium ring. However, this part of the cation plays an important role when clusters of ion pairs in the gas phase and inside a crystal lattice are considered. For example, in the dimeric ion-pair cluster, one centre (O*) with two interaction sites (C(2)-H-O* and alkyl OH-Pic) is observed. This configuration is suggested by single crystal X-ray diffraction (XRD), vibrational spectroscopy, and the dispersion-corrected DFT calculations. Hence, the study provides evidence for the appearance of theoretical gas phase clusters in an actual solidified ionic liquid. This ion pair dimer formation may be a general behavior of hydroxyl functionalized imidazolium ILs, but further research is needed to draw a final conclusion. Moreover, the Raman spectra confirm the exclusive gauche conformation of the hyroxyl functionalized alkyl chain.

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Section: Resultssupporting

confidence: 88%

Clusters of the Ionic Liquid 1‐Hydroxyethyl‐3‐methylimidazolium Picrate: From Theoretical Prediction in the Gas Phase to Experimental Evidence in the Solid State

2018

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“…The wide band of peaks in the range of 3600-3000 cm -1 indicates the presence of stretching vibrations of the O-H polysaccharide bonds, whereas the peak at 2900 cm -1 is attributed to the tensile vibrations of the C-H bonds of the polysaccharide (Hospodarova et al 2018). The peak in the range of 1640-1650 cm -1 indicates the presence of water (H 2 O molecules) in material structure (Kiefer et al 2016). Peaks at 1429, 1380, and 1318 cm -1 are indicative of successive wagging in the plane, stretching and bending of the C-H bond.…”

Section: Resultsmentioning

confidence: 99%

The use of aminated cotton fibers as an unconventional sorbent to remove anionic dyes from aqueous solutions

et al. 2020

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This study aimed to investigate the sorption of anionic dyes (Reactive Black 5, Reactive Yellow 84, Acid Red 18, and Acid Yellow 23) by cotton fibers aminated with epichlorohydrin and ammonia water (ACFs) as well by unmodified cotton fibers (CFs). CFs and ACFs were characterized based on FTIR, elemental analysis (C/N content) and pH PZC . The effect of solution pH (pH 2-11) and contact time on the removal of dye was studied as well. The kinetic experimental data were fitted to pseudo-first order, pseudo-second order, and intraparticle diffusion model. Equilibrium isotherms were analyzed based on Langmuir and Freundlich isotherms. The efficiency of dye sorption on CFs was the most effective at pH 2, whereas on ACFs-at pH 3-4. ACFs and CFs changed the pH value of the sorption solution. The system tended to obtain a pH value close to the pH PZC value of the sorbent (pH PZC = 7.85 for CFs/pH PZC = 8.15 for ACFs). ACFs had a shorter dye sorption equilibrium time compared to the CFs. The sorption of dyes on cotton sorbents proceeded in 2 main phases. The best match to the experimental data was shown by the pseudo-secondary model. Having amine functional groups, the ACFs ensured far better sorption of anionic dyes than CFs did. The maximum Reactive Black 5 sorption capacity of ACFs was Q max = 36.77 mg/g, which was 1240% higher than that of CFs (Q max-= 2.74 mg/g).

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“…The emulsifier composition (v/v) was S80/T80 at 54/46 (HLB 9.2) and 80/20 ratios (HLB 6.4), and S85/T80 at 80/20 ratio (HLB 4.4), coded as S80/T80 54/46, S80/T80 80/20 and S85/T80 80/20, respectively. The chosen HLB range (4)(5)(6)(7)(8)(9), which in the classical HLB scale covers W/O and wettability agents, was chosen to be further experimentally validated as effective stabilizers for W/O systems. The used content of emulsifier was 6% (total emulsion-basis, v/v (%)).…”

Section: Systematic Study and Base Emulsion Selectionmentioning

confidence: 99%

“…Water-in-oil (W/O) emulsions consist of an aqueous phase dispersed, in the form of small droplets, into a continuous oil phase [3,4]. W/O emulsions have high potential for cosmetic, pharmaceutical, agricultural, and food industries [3,[5][6][7]. For example, this type of emulsion can be used for the encapsulation of medicines, immobilizing enzymes, and loading protein drugs [5,8,9].…”

Section: Introductionmentioning

confidence: 99%

Development of Water-in-Oil Emulsions as Delivery Vehicles and Testing with a Natural Antimicrobial Extract

et al. 2020

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Water-in-oil (W/O) emulsions have high potential for several industrial areas as delivery systems of hydrophilic compounds. In general, they are less studied than oil-in-water (O/W) systems, namely in what concerns the so-called fluid systems, partly due to problems of instability. In this context, this work aimed to produce stable W/O emulsions from a natural oil, sweet almond oil, to be further tested as vehicles of natural hydrophilic extracts, here exemplified with an aqueous cinnamon extract. Firstly, a base W/O emulsion using a high-water content (40/60, v/v) was developed by testing different mixtures of emulsifiers, namely Tween 80 combined with Span 80 or Span 85 at different contents. Among the tested systems, the one using a 54/46 (v/v) Span 80/Tween 80 mixture, and subjected to 12 high-pressure homogenizer (HPH) cycles, revealed to be stable up to 6 months, being chosen for the subsequent functionalization tests with cinnamon extract (1.25–5%; w/v; water-basis). The presence of cinnamon extract leaded to changes in the microstructure as well as in the stability. The antimicrobial and antioxidant analysis were evidenced, and a sustained behavior compatible with an extract distribution within the two phases, oil and water, in particular for the higher extract concentration, was observed.

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Infrared Spectroscopy of Bilberry Extract Water-in-Oil Emulsions: Sensing the Water-Oil Interface

Cited by 25 publications

References 24 publications

Clusters of the Ionic Liquid 1‐Hydroxyethyl‐3‐methylimidazolium Picrate: From Theoretical Prediction in the Gas Phase to Experimental Evidence in the Solid State

Clusters of the Ionic Liquid 1‐Hydroxyethyl‐3‐methylimidazolium Picrate: From Theoretical Prediction in the Gas Phase to Experimental Evidence in the Solid State

The use of aminated cotton fibers as an unconventional sorbent to remove anionic dyes from aqueous solutions

Development of Water-in-Oil Emulsions as Delivery Vehicles and Testing with a Natural Antimicrobial Extract

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