The elastic properties of sodium montmorillonite suspensions

Shear wave rigidity moduliG have been determined using a shear wave propagation technique for sodium montmorillonite suspensions. Measurements were made as a function of time at various values of pH, NaCl concentration (C) and solids concentration and the data used to estimateG _e the value of the modulus att=. The dependency ofG _e on pH,C and solids concentration is interpreted in terms of the mode of interaction between particles and the associated volume filling structure. The results suggest that whether a coagulated or dispersive structure develops in these suspensions depends not only on pH andC but also on the degree of delamination of the clay.     

Chitosan-encapsulated Keggin Anion [Ti2W10PO40]7−. Synthesis, Characterization and Cellular Uptake Studies

The Keggin type polyoxotungstate [Ti₂W₁₀PO₄₀]⁷⁻ forms stable associates with the biopolymer chitosan in the nanometer size range. The cluster compound crystallizes from aqueous solution as K₄H₃[Ti₂W₁₀PO₄₀] · 15H₂O having a tetragonal structure. Both, the cluster compound and the chitosan/[Ti₂W₁₀PO₄₀] associates show a high hydrolytic stability at pH 7.4. The associates formed between the cluster anion [Ti₂W₁₀PO₄₀]⁷⁻ with the polyaminosaccharide chitosan have been characterized by photon correlation spectroscopy, scanning electron microscopy, filtration, centrifugation and zeta potential measurements. The size of the associates formed is in the range of ca. 5×10¹ to 5×10² nm. These particles have a defined stoichiometry with 5–6 cluster anions bound per molecule chitosan. The isoelectric point determined by zeta potential measurements was found for a cluster anion to chitosan molar ratio of 5.5, indicating the charge neutralization between protonated chitosan and [Ti₂W₁₀PO₄₀]⁷⁻ anions. Cellular uptake studies with [Ti₂W₁₀PO₄₀]⁷⁻ using tumor cell lines FaDu (human squamous carcinoma) and HT-29 (human adenocarcinoma) showed that the tungsten amount inside the cells is remarkably enhanced in the presence of chitosan.     

Zymomonas mobilis as catalyst for the biotechnological production of sorbitol and gluconic acid

The conversion of glucose and fructose into gluconic acid (GA) and sorbitol (SOR) was conducted in a batch reactor with free (CTAB-treated or not) or immobilized cells of Zymomonas mobilis. High yields (more than 90%) of gluconic acid and sorbitol were attained at initial substrate concentration of 600 g/L (glucose plus fructose at 1:1 ratio), using cells with glucose-fructose-oxidoreductase activity of 75 U/L. The concentration of the products varied hyperbolically with time according to the equations (GA)=t(GA)_max/(W_GA +t), (SOR)=t (SOR)_max/(W_Sor+t), v_GA=[W_GA (GA)_max]/(W_GA+t)² and V_SOR=[W_SOR (SOR)_max]/(W_SOR+t)². Taking the test carried out with free CTAB-treated cells as an example, the constant parameters were (GA)_max= 541 g/L, (SOR)_max=552 g/L, W_GA=4.8h, W_SOR=4.9h, υ_GA=112.7 g/L· and υ_SOR=112.7 g/L·.     

Aggregate morphology and flow behaviour of micellar alkylglycoside solutions

Solutions of n-nonyl-β-D-glucoside (C₉G₁), n-decyl-β-D-glucoside (C₁₀G₁), n-dodecyl-β-D-maltoside (C₁₂G₂), n-tetradecyl-β-D-maltoside (C₁₄G₂) and C₉G₁/C₁₀G₁ mixtures have been characterised by capillary viscometry and rheology in H₂O and D₂O, in order to map the influence of surfactant characteristics on micellisation over a wide concentration range. For the maltosides, the micellar solutions are shear thinning with a zero-shear viscosity that scales with concentration according to a power law with an exponent of about 5.8. In contrast, solutions of the glucosides C₉G₁, C₁₀G₁ and their mixtures show Newtonian flow behaviour and a much lower scaling exponent (<2.4). In C₉G₁/C₁₀G₁ mixtures, the scaling exponent decreases monotonously with increasing C₁₀G₁ content. The flow behaviour correlates with the packing requirements of the various surfactants, and are compatible with the idea that the maltosides form worm-like micelles, whereas the glucosides form branched, interconnected micelles (C₉G₁) and space-filling micellar networks (C₁₀G₁).     

Effect of Organic Counterions on the Properties of N-Lauryl Diisopropanolamine Surfactants

The influence of counterions on the surface properties of N-lauryl diisopropanolamine surfactants is delineated using conductometry and surface tension measurements. Twelve types of organic counterions have been studied: C₁–C₁₂ monocarboxylic acids anions. The surface properties of the synthesized surfactants, including surface tension, critical micelle concentration (CMC), effectiveness (π_CMC), efficiency (pC₂₀), maximum surface excess (Γ_max), minimum surface area (A_min), Gibbs energy of micellization (ΔG_mic), and adsorption (ΔG_ad) processes in the aqueous. The biodegradability of the prepared surfactants was tested in river water using the die-away method. Petroleum-collecting and petroleum-dispersing capacities of the synthesized compounds on the surface of water of varying mineralization degree have been studied.     

Sorption of tungsten on alumina in dynamic conditions

Summary The sorption of tungstate anions on alumina from aqueous solutions of sodium chloride was investigated in dynamic conditions. The breakthrough curves as the function of W and NaCl concentrations, pH and the flow rates were determined. The breakthrough capacities, the capacities at C/C₀=0.5, the total column sorption capacities and the utilization degrees or column efficiencies, were determined. The obtained tungstate anion sorption data fit with a Langmuir-type isotherm. The values of the breakthrough capacity, Q_0,9^max,the Langmuir equilibrium constant or affinity parameter, K_L, and the free energy change, ΔG, of tungsten sorption were also determined.     

Dynamic rheology studies of in situ polymerization process of polyacrylamide–cellulose nanocrystal composite hydrogels

A series of dynamic small-amplitude oscillatory shear experiments for in situ polymerization process of polyacrylamide–cellulose nanocrystal (PAM–CNC) nanocomposite hydrogels were performed to investigate the relationship between rheological properties and synthesis parameters including chemical cross-linker concentration, polymerization temperature, initiator concentration, and CNC aspect ratios. The results showed that CNCs accelerated the onset of gelation (t _onset) and acted as a multifunctional cross-linker during the gelation reaction. The composite hydrogels exhibited enhanced steady-state elastic modulus ( G_￥￠ ) \left( {G_\infty^\prime } \right) and plateau loss factor (tanδ) compared to these of the pure PAM hydrogels, indicating that adding CNCs not only reinforced but also toughened PAM hydrogels. ( G_￥￠ ) \left( {G_\infty^\prime } \right) and the effective network junction density (N) increased with increased cross-linker concentration, polymerization temperature, and CNC aspect ratios, but decreased with increased initiator concentration. The changes of plateau tanδ were opposite to that of G_￥￠ G_\infty^\prime . The sol–gel transition kinetics of PAM–CNC hydrogels accelerated with increased cross-linker concentration and polymerization temperature and, however, reached optimization at 0.25 wt% of initiator concentration. CNCs with lower aspect ratios promoted t _onset and the sol–gel transition of PAM–CNC hydrogels, suggesting the fact that CNCs with lower aspect ratios further facilitated the formation of network of PAM–CNC nanocomposite hydrogels.     

Contact electroresistance of metals in aqueous solutions during the anion adsorption involving charge transfer

Notions about charge transfer during adsorption of anions on metals in aqueous solutions are rendered. The role played by the electron tunneling on macrocontacts during the signal formation in the method of contact electroresistance (CER) is considered. It is shown that CER depends on the metal surface coverage by adsorbed species and their effective charge. Bell-like CER vs.E curves are obtained for copper, silver, and gold in solutions containing halide ions. Potentials of maximums in the curves,E _max, correspond to the charge transfer onset and depend on the nature of the metal and anion and on the anion concentration. AtE belowE _max, halides adsorb in the form of ions, involving no substantial charge transfer. At potentials exceedingE _max by 0.1 to 0.2 V, practically complete charge transfer occurs. With changing anion nature,E _max for a given metal rises in the series I^- < Br^- ≪ Cl^-. For a given anion (say, I^-),E _max increases with the metal nature in the series Cu ≤Ag ≪ Au. The link between the charge transfer during adsorption of anions and the surface reconstruction in single-crystal electrodes is discussed.     

Thermal,viscoelastic, and mechanical properties of DCPD-containing polymers

The thermal, viscoelastic, and mechanical properties of cured dicyclopentadiene (DCPD)-containing polymers prepared from novel DCPD-modified unsaturated epoxypolyesters and styrene were evaluated. This was accomplished using thermogravimetric analysis, differential scanning calorimetry, dynamic mechanical analysis, three-point bending test, and Brinell’s hardness. The thermal, viscoelastic, and mechanical properties of DCPD-containing polymers were strongly dependent on chemical structure. The cross-linking density (υ _e) of obtained networks increased with increasing content of carbon–carbon double bonds in the poly(ester) structure. In addition, the introduction of DCPD rings into the poly(ester) structure increased the rigidity of the molecular backbone. It resulted in obtaining polymers which showed great improvement in mechanical properties including remarkably higher storage modulus ( E_{20 ^°\textC}^￠ E_{{20\,{}^{\circ}{\text{C}}}}^{'} ), flexural modulus at bending (E _mod), hardness, lower extension at maximum force (ε-F _max), as well as higher thermal stability. These good properties make these materials highly promising as potential candidates for structural applications.     

Dimerization and Coordination Properties of Zinc(II)tetra-4-alkoxybenzoyloxiphthalocyanine in Relation to DABCO in <Emphasis Type="Italic">o</Emphasis>-Xylene and Chloroform

For the first time the interactions between zinc(II)tetra-4-alkoxybenzoyloxiphthalocyanine (Zn(4—O—CO—C₆H₄—OC₁₁H₂₃)Pc) and 1,4-diazabicyclo[2.2.2]octane (DABCO) in o-xylene and chloroform have been studied by calorimetric titration and NMR and electron absorption spectroscopic methods. It has been found that in o-xylene at concentrations of Zn(4—O—CO—C₆H₄—OC₁₁H₂₃)Pc higher than 6×10⁻⁴ mol⋅L⁻¹ π–π dimers species are formed (λ _max= 685 nm). Additions of DABCO to the solution up to mole ratio 1 : 8 (Zn(4—O—CO—C₆H₄—OC₁₁H₂₃)Pc : DABCO) lead to a shift of the aggregation equilibrium towards monomer species due to formation of monoligand axial complexes. Further increasing the DABCO concentration results in formation of Zn(4—O—CO—C₆H₄—OC₁₁H₂₃)Pc—DABCO—Zn(4—O—CO—C₆H₄—OC₁₁H₂₃)Pc sandwich dimers (λ _max= 675 nm).     

Dynamic surface tension and dilational viscoelasticity of adsorption layers of alkylated chitosans and surfactant–chitosan complexes

The kinetics of the adsorption at the air-water interface and the processes of the structure formation inside the adsorption layers of hydrophobically modified systems [alkylated chitosans and sodium dodecyl sulfate (SDS)–chitosan (Ch) complexes] have been studied by the tensiometric method based on the axisymmetric rising-bubble-shape analysis as a function of the bulk concentration of polymers and the ageing time of their adsorption layers. The kinetics of the adsorption of chitosan, alkylated chitosans (ChC₃, ChC₈, and ChC₁₂), and surfactant–polyelectrolyte (PE) complexes formed by the chitosan and the polysoaps with oppositely charged anionic surfactant SDS is characterized by an induction time (the so-called lag time), τ_lag, corresponding to the diffusion stage of the formation of adsorption layers. During this time, the decrease in the surface tension (or the increase in the surface pressure π) does not exceed several millinewtons per meter that corresponds to the “gaseous” state of adsorption layers. The postlag stage of the formation of the adsorption layer is characterized by the remarkable rate of increase in the surface pressure π that corresponds to the conformational rearrangement of PEs inside the adsorption layer by increasing the number of hydrophobic groups (adsorbing centres) in contact with the non-polar phase at the interface. It has been found that during the lag time, the adsorption of alkylated chitosans (cationic polysoaps) increases with increasing alkyl chain length, whereas during the postlag time, the adsorption of the ChC₃ is maximal with regard to other polysoaps. It has been confirmed that at equal content of alkyl groups in the system, the surface activity of the SDS–Ch complexes is much higher with regard to that of the polysoaps. The viscoelasticity of adsorption layers of individual PEs and their complexes continuously increases with the ageing time, giving evidence for the interaction between the polymers inside the adsorption layers. It has been found that the rate of increase in the dilational storage module E′ of the adsorption layers of SDS–Ch complexes is much higher than for the polysoaps that correlates with the higher surface activity of the former with regard to the latter. For the mentioned systems, the module E′ is much higher than the loss module E″ that confirms the solid-like properties of their adsorption layers. On the other hand, the adsorption layers of the chitosan are liquid-like, while E′<<E′′.     

Rheological properties of wormlike micelles in sodium oleate solution induced by sodium ion

Aqueous solutions of anionic surfactant, sodium oleate (NaOA), have been studied by means of steady-state shear rheology and dynamic oscillatory technique. The micellar structure can be changed upon the addition of NaCl, Na₂CO₃ and NaCl/NaOH while NaOA concentration is maintained at 0.060 M. These systems except NaOA/NaCl show high viscosity and strong viscoelasticity. The hydroxide ion is very important for the formation of wormlike micelles. The anions of salts also have effect on the rheological properties of wormlike micelles. Three parameters: intersection frequency ω_i, plateau modulus G₀ and relaxation time τ are also discussed. The Maxwell model and Cole-Cole plot are applied to investigate the dynamic viscoelasticity of wormlike micelles. Variation in surfactant packing parameter R_P can be used to explain the change of rheology and microstructure of the micelles.     

Interaction between cetyltrimethylammonium bromide and β-cyclodextrin: surface tension and interfacial dilational viscoelasticity studies

The interaction between cetyltrimethylammonium bromide (CTAB) and β-cyclodextrin (β-CD) was studied via surface tension and dilational viscoelasticity methods. The effect of sodium bromide and sodium chloride on the interaction between CTAB and β-CD were studied as well. The surface tension isotherms provided a series of parameters, including apparent critical micelle concentration (cmc*), surface tension at the cmc* (γ_cmc), stoichiometry of the complex (R), and the efficiency of adsorption (pC ₂₀ ). The addition of NaBr and NaCl decreases the cmc* of CTAB/β-CD solution. CTAB molecules enter the cavities of β-CD molecules thus formed both 1:1 and 1:2 inclusion complexes. From the change of γ_cmc, it can be seen that the CTAB/β-CD complexes (1:1) act as short-chain alcohol, which decrease γ_cmc, but the depression of cmc* is too small to be detected. R first decreases then increases as a function of NaBr and NaCl. Compared to NaCl, NaBr increases R more efficiently. The presence of NaBr and NaCl increases pC ₂₀ of CTAB/β-CD solution. The results obtained from the dilational viscoelasticity measurements at low dilational frequencies (0.005–0.1 Hz) reveal that the dilational modulus passes through a maxium value with increasing concentration of β-CD at a given concentration of CTAB. The addition of both NaBr and NaCl decreases the dilational modulus of a given concentration CTAB/β-CD solution. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

A New Molecular Theory of Non‐Linear Viscoelasticity for Vitrifiable (or Crystallizable) Thermoplastic Polyurethane Elastomers

The molecular theory of non‐linear viscoelasticity for vitrifiable thermoplastic polyurethane elastomers (VTPUE) is a refinement and extension of viscoelastic theory of thermoplastic elastomers and polyurethanes to glassy transition, a structural model and a mechanism of vitrification for glassy polymers were proposed. Five kinds of constituent chains with Nagai chain constraint consisting of soft‐domains, hard‐domains, and entanglements are used as the elementary structural and statistical ensemble units for the correlation of molecular and phase‐domain structures to the static and dynamic mechanical behaviors. So the influences of non‐Gaussian in character, the phase separation of domain, the network topology of structure, the affined deformation of constituent chains, and the thermal history are all taken into account in the constituent chains of the theory. Free energies of deformation for the VTPUE segment copolymer were calculated by the statistical mechanics with the probability distribution functions of the sizes for the five kinds of constituent chains. Then the static constitutive equations and modulus of four types of deformation and the dynamic shear viscosity, modulus and loss tangent of VTPUE are derived from the proposed theory. The theory is successful in relating the molecular chain parameters C₁₀₀, C₀₂₀, and C₂₀₀ to the constitutive equations and modulus under large deformations and the micro‐domain structure to the complex shear viscosity and modulus and the loss tangent. The dynamic shear modulus and loss tangent of VTPUE are related to the domain structures through the fraction of hard segments (W_h), the molecular weight of soft segment (M_ns), and the growth dimensional parameters of hard and soft domains (β). Two series of linear VTPUE copolymers (ES and ET) with different fractions(W_h) of hard segments and molecular weight (M_ns) of soft segments were prepared. Their static and dynamic mechanical properties were studied by uni‐axial extension and dynamic analysis tests. Then the constitutive equation at uni‐axial extension and the expressions of shear modulus and loss tangent are verified by these experimental data, and excellent agreement between the theory and experiments is achieved. It is shown, that the proposed theory can predict the viscoelastic behavior of vitrifiable thermoplastic polyurethanes.     

由碳酸钠诱导形成的油酸钠蠕虫状胶束的流变学性质

当Na₂CO₃浓度逐渐增加时, 用流变学的方法研究了阴离子表面活性剂油酸钠(NaOA)在溶液中从胶束转变成蠕虫状胶束的过程. 首先测量体系剪切粘度(η)和剪切速率的关系得到零剪切粘度(η₀). 然后由动态振荡实验得到复合粘度(|η^*|)、动态模量(储能模量G'、损耗模量G"和结构松弛时间τ_s)等物理量. 应用Cox-Merz规则和Cole-Cole图, 证明NaOA (0.040～0.080 mol/L)/Na₂CO₃ (0.25～0.50 mol/L)体系形成蠕虫状胶束, 且蠕虫状胶束的动态粘弹性在NaOA (0.050～0.080 mol/L)/Na₂CO₃ (0.35～0.45 mol/L)范围是符合Maxwell模型的线性粘弹性流体.     

Relationship between the positive temperature coefficient of resistivity and dynamic rheological behavior for carbon black‐filled high‐density polyethylene

Studies on the relationship between resistivity and dynamic rheological properties of carbon black‐filled high‐density polyethylene (CB/HDPE) composites were carried out. Change of resistivity ρ is associated with the dynamic modulus before the positive temperature coefficient/negative temperature coefficient (PTC/NTC) transition temperature. When the temperature approaches the melting point of HDPE, ρ increases rapidly with a decreasing modulus, corresponding to PTC transition. The resistivity‐dynamic viscoelasticity relationship in the PTC region can be divided into two parts in which the changes of ρ with storage modulus G′ and loss modulus G″ can be described by the scaling laws given by the critical storage modulus and loss modulus G′_c and G″_c; adjustable parameters ρ′_1c, ρ′_2c, ρ″_1c and ρ″_2c; and nonlinear exponents n and m, respectively. The accordance between the experimental data and the scaling functions of the dimensionless quantities (G′/G′_c ? 1) and (G″/G″_c ? 1) in the PTC transition region suggests that the ρ jump may be the result of a modulus‐induced percolation. G′_c and G″_c increase, but the four scaling resistivitis, ρ′_1c, ρ′_2c, ρ″_1c, and ρ″_2c, decrease with increasing CB concentration, implying that the microstructure change of the composites is the determinant factor for the PTC behavior and the resistivity‐dynamic modulus relationship. However, ρ′_2c and ρ″_2c exhibit no scaling dependence. It is suggested that a threshold concentration exists for the modulus of the composites on the basis of examining the plot of both G′_c and G″_c against CB concentration. The scaling laws G′ ～ Φ^x and G″ ～ Φ^y hold for the concentration dependence of the critical modulus when Φ > Φ_c and the estimated values of x and y are 1.10 ± 0.10 and 0.89 ± 0.29, respectively. The resistivity‐dynamic modulus can shift to form a master curve. The horizontal factors a_G′ and a_G″ and the vertical factors a′ and a″ are relevant to the concentration dependence of the dynamic modulus or PTC behavior. It is believed that the former would be involved in changing the mechanical microstructure formed by the complicated interaction of CB particle and polymer segments, and the latter would be involved in the overall changes of conducting a network during the PTC transition region. © 2003 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 41: 983–992, 2003     

Viscoelastic properties of crosslinked solutions of poly(2-hydroxymethyl methacrylate) in diethylene glycol. VI. Comparison with poly(butyl methacrylate) and poly(butyl acrylate) networks crosslinked to very low degrees

On the basis of our own experimental and some literature data, the contributions of slow relaxation mechanisms to the shear modulus, (G_eN — G_e), and the parameter C₂ of the Mooney-Rivlin equation have been examined for lightly crosslinked poly(butyl methacrylate), poly(butyl acrylate), poly(2-hydroxyethyl methacrylate), and some rubber networks. For the rubbers, increasing degree of crosslinking caused a decrease in G_eN — G_e and an increase in C₂; for the other networks, both G_eN — G_e and C₂ diminished with increasing crosslinking. The effectiveness of the crosslinking polymerization, and also the absolute values of the physical crosslinking degree, decreased in the order of poly(2-hydroxyethyl methacrylate), poly(butyl methacrylate), and poly(butyl acrylate). The values of the equilibrium compliances J of the networks studied, obtained by various methods, have also been compared, and good agreement has been found.     

Rheological studies of aqueous alkylpolyglucoside surfactant solutions

Alkylpolyglucosides (C _Y G _X ) are industrial products of mixtures consisting of a hydrocarbon chain with Y carbon atoms linked to X sugar residues. Based on detailed analytical investigation of technical grade alkylpolyglucosides (C_8–10G _X , C_12–14G _X and C_8–16G _X )/water systems using high-performance liquid chromatography in combination with a special kind of mass spectroscopy their rheological behaviour is discussed and compared to the rheological behaviour of pure alkyl monoglycosides (C₈G₁ and C₁₀G₁) in water. The rheological properties that exhibit a dependence on the alkyl chain length, Y, and the degree of polymerisation, X, are investigated by rotation and oscillation experiments over an extended concentration range. The Maxwell model fits the frequency dependence of the dynamic functions fairly well. The viscosity shows an Arrhenius-like dependence on temperature. A comparison is drawn between the monoglucosides and the polyglucosides, which shows that the rheological properties are more sensitive to the a change in chain length than in the degree of polymerisation. Phase transitions, especially liquid-crystalline to isotropic solutions, phase split into two coexisting liquid phases, and could be followed using visual observation and rheology. Depending on the difference in the rheological properties of the corresponding phases, viscoelastic measurements showed these transitions clearly. Additionally, the changes in viscosities were measured after addition of a second surfactant. Received: 4 January 1999 Accepted in revised form: 12 April 1999     

Association behavior of one-end hydrophobically modified poly[<Emphasis Type="Italic">N</Emphasis><Superscript>5</Superscript>-(2-hydroxyethyl) <Emphasis Type="SmallCaps">l</Emphasis>-glutamine] in water/ethylene glycol mixed solvent

Amphiphilic polymers Cn-PHEG consisting of water-soluble poly[N ⁵-2-(hydroxyethyl) l-glutamine] (PHEG) and hydrophobic alkyl chain (carbon number n = 12, 14, 16, or 18) attached at the PHEG terminal was prepared, and association behavior and structure of associate for Cn-PHEG in selective solvent (water/ethylene glycol mixed solvent) have been investigated. α-Helix content of PHEG block for all the polymers increased with weight fraction of ethylene glycol in the mixed solvent (W _EG). By light scattering measurements, formation of a small micelle was suggested for C14-, C16-, and C18-PHEG when W _EG = 0. With the increase in W _EG, appearance of a larger associate was revealed for C16- and C18-PHEG. Evaluated molecular weight and radius of gyration suggested that the micelle is star-like sphere when W _EG = 0 and worm-like cylinder when W _EG = 0.7. C12-PHEG did not demonstrate any distinct micellization behavior because of the weak hydrophobicity of C12 chain.     

Review of: “Physico-Chemical Properties of Selected Anionic Cationic and Nonionic Surfactants”. N.M van Os,J.R. Haak and L.M. Rupert (Eds.). Elsevier,Amsterdam, 1993, pp. viii + 608 pages. $245.75.(ISBN 0-444-89691-0)

The phase behavior in water of pentaglycerol monostearate (C₁₈G₅) and pentaglycerol monooleate (C_18:1G₅) surfactants has been studied as a function of temperature and surfactant weight fraction, W _s . The equilibrium phases present at each composition and temperature studied were characterized by means of visual observation under normal and polarized light, differential scanning calorimetry (DSC), and X‐ray scattering, both at small (SAXS) and at wide angle (WAXS). In the temperature range 0–46°C, C₁₈G₅ presents a thermotropic α‐gel structure. However, at higher temperatures, the α‐gel phase melts and a lamellar liquid crystalline (L_α) phase is formed. The amount of water that can be solubilized by α‐gel and L_α was determined by plotting the interlayer distance, d, as a function of the reciprocal of W _s . Water is soluble in the α‐gel phase up to 21 w/w% water concentration and in the L_α phase up to 30 w/w% water concentration. At higher water concentrations, excess water appears and a dispersion of α‐gel (α‐gel+W) and lamellar liquid crystal (L_α+W) in water is formed, respectively. In contrast, C_18:1G₅ is liquid in the whole range of temperatures studied (0–100°C). While at low temperatures, C_18:1G₅ presents a L_α structure, at about 63°C L_α melts and an isotropic liquid reverse micellar solution (O_m) phase is formed. The amount of water that can be solubilized by both O_m and L_α increases with temperature.