Hydrohysteretic Phenomena of “Extremely Diluted Solutions” Induced by Mechanical Treatments: A Calorimetric and Conductometric Study at 25 <Superscript>∘</Superscript>C

The purpose of this study was to obtain information about the influence of successive dilutions and succussions (violent shaking) on the structure of water. “Extremely diluted solutions” (EDS) are solutions obtained through the iteration of two processes: 1:100 dilution and succussion. Those two processes are repeated until extreme dilutions are reached, so that the chemical composition of the end solution is identical to that of the solvent. We measured the heats of mixing and the electrical conductivity of basic solutions of such EDS, and compared these results with the analogous heats of mixing and electrical conductivity of the untreated solvent. The measurements were carried out as a function of the age of the samples. We found some relevant exothermic excess heat of mixing, and higher electrical conductivity than those of the untreated solvent, also in function of time. The measurements show a good linear correlation between the two independent physico-chemical quantities, implying a single cause for this behavior of the extremely diluted solutions. The slopes of the linear correlation depend on the age of the EDS. Such a phenomenon could result from a variation of the shape of molecular aggregates that characterize the two different supramolecular structures of the water of different ages. This behavior could provide important support for understanding the nature of the phenomena described herein. A really intriguing phenomenon is the evolution of some physico-chemical properties with time. This hints at a “trigger” effect on the formation of molecular aggregates that result from the succussion procedure. We show that successive dilutions and succussions can permanently alter the physico-chemical properties of the aqueous solvent, the extent of which depends on the age of the samples.     

New Physico-chemical Properties of Water Induced by Mechanical Treatments. A calorimetric study at 25°C

An extensive thermodynamic study has been carried out on aqueous solutions, obtained through the iteration of two processes: a dilution 1:100 in mass and a succussion. The iteration is repeated until extreme dilutions are reached (less than 1⋅10^–5 mol kg^–1 ) to the point that we may call the resulting solution an 'extremely diluted solution'. We conducted a calorimetric study, at 25°C, of the interaction of those solutions with acids or bases. Namely, we measured the heats of mixing of acid or basic solutions with bidistilled water and compared them with the analogous heats of mixing obtained using the 'extremely diluted solutions'. Despite the extreme dilution of the latter solutions, we found a relevant exothermic excess heat of mixing, excess with respects to the corresponding heat of mixing with the untreated solvent. Such an excess has been found in about the totality of measurements, and of a magnitude being well beyond one that could arise any issue of sensibility of the instrumental apparatus. Here we thus show that successive dilutions and succussions can permanently alter the physico-chemical properties of the solvent water. The nature of the phenomena here described still remains unexplained, nevertheless some significant experimental results were obtained. This revised version was published online in July 2006 with corrections to the Cover Date.     

New physico-chemical properties of extremely diluted aqueous solutions

The 'extremely diluted solutions', anomalous solutions prepared through the iteration of a process of dilution and succussion, have been studied with the aim of obtaining information about the influence of the preparation method on the water structure of the solutions. We measured the heats of mixing of basic solutions with such 'extremely diluted solutions', and their electrical conductivity, comparing with the analogous heats of mixing, electrical conductivity of the solvent. We found some relevant exothermic excess heats of mixing, and higher conductivity than those of the untreated solvent. The heats of mixing and electrical conductivity show a good correlation, underlining a single cause for the behaviour of the extremely diluted solutions. This revised version was published online in July 2006 with corrections to the Cover Date.     

New Physico-Chemical Properties of Extremely Dilute Solutions. A Conductivity Study at 25 °C in Relation to Ageing

The conductivity of extremely dilute solutions (EDS) was measured and studied in relation to the age of the solutions. The aim was to obtain information about the influence of succussive dilutions and succussions on the conductivity and structure of water. EDS are obtained by iteration of two processes: dilution 1:100 (mass basis) and succussion. The iteration is carried out until extreme dilutions are reached. We found significant increases in electrical conductivity with respect to the untreated demineralized water used as solvent, confirming the intriguing new behavior disclosed some time ago, namely the evolution of certain physico-chemical parameters with the age of the samples. We studied variations in electrical conductivity of samples up to two years old. Conductivities showed large variations reaching a pronounced maximum and, for several samples, then returning to their initial values. The latter fact suggests that the temporal evolution of this physico-chemical parameter does not stem from the slow attainment of an equilibrium condition, characterized by a minimum of energy, since that state, when reached, should be steady. These systems could be far from thermodynamic equilibrium, producing dissipative structures. In order to stay far from equilibrium, they need to dissipate energy. For reasons that are not yet clear, when modified environmental conditions prevent the necessary dissipation of energy, these systems return to their initial conditions. In the light of this interpretation, the succussion procedure may be the trigger for the formation of dissipative structures, the number and/or size of which increase with age, up to a certain point.     

Calorimetric and conductometric titrations of nanostructures of water molecules in iteratively filtered water

This work continue the study of the physico-chemical properties of samples of pure, twice distilled water, when subject to a procedure of iterative filtrations through Pyrex glass filters (Büchner funnels). After the filtrations, electrical conductivity and heat of mixing with NaOH and HCl solutions increase. The hypothesis is that the iterative filtration procedure, that involves a flux of energy and material in an open system, is able to induce the formation of “dissipative structures” or nanostructures of water molecules (WNS). Water exhibits an extraordinary auto-organization potentiality triggered by several kinds of perturbations, including mechanical ones. We measured the heats of mixing of acid or basic solutions with such iterated filtered waters (IFW) and their electrical conductivity, comparing with the analogous heats of mixing, electrical conductivity of the solvent. We found some relevant exothermic excess heats of mixing and higher conductivity than those of the untreated solvent. The heats of mixing and electrical conductivity of IFW show a good correlation, underlining a single cause for the behavior of the samples.     

‘Extremely diluted solutions’ as multi-variable systems

A large number of thermodynamic and transport measurements were conducted on ‘extremely diluted solutions’ (EDS). The physico-chemical results presented here allow us to hypothesize that the process of iterated dilutions and succussions is capable of modifying in a permanent way the features of water. A really intriguing phenomenon was the evolution of two physico-chemical properties with time. The calorimetric and conductometric measures were carried out as a function of the age of the samples. We found a good linear correlation between these two independent parameters, also as a function of time. A careful study of the phenomenon puts in evidence that these solutions are characterised by multiple independent variables. The EDS behave as complex systems, influenced by peculiar aspects of the preparation technique and also by the storage conditions. The EDS are far-from-equilibrium systems, capable of auto-organising themselves as a consequence of little perturbations.     

The role of ethanol in extremely diluted solutions

We carried out a systematic study on the role of ethanol as a cosolvent in the preparation of aqueous extremely diluted solutions (EDS). We have studied EDS prepared in water containing 1 % ethanol and measured their electrical conductivity and heat of mixing to determine how these solutions differ from those prepared in pure water. The results showed that, as occurs also for the EDS in water, these ethanolic solutions exhibit peculiar effects relating to container volume and storage time (ageing). Our data show a remarkable increase in the conductivity of the EDS in 1 % ethanol, as compared to EDS prepared in water solvent, especially after prolonged storage higher than about 250 days (ageing effect). In each case, the values of conductivity for the hydroalcoholic solvent were approximately four times those for water after an ageing period of 2,178 days. For the study of volume effect, we found that conductivity changes only slightly with decreasing volume. It’s important to underline that the studied volumes were in the 0.25/2.0 mL range. The calorimetric measurements reveal that the presence of ethanol affects heat of mixing with alkaline solutions differently compared to the conductivity. In fact, heat of mixing is not very sensitive to the presence of ethanol, but in contrast with conductivity it shows remarkable sensitivity to volume effects. Our working hypothesis to account for these peculiarities is the presence of water molecule aggregates.     

On the stability of extremely diluted aqueous solutions at high ionic strength

An extensive study has been carried out on extremely diluted aqueous solutions (EDS). These solutions revealed a really intriguing physico-chemical behaviour, characterized by multiple independent variables. Because of their behaviour, EDS can be described as far-from-equilibrium systems, capable of self-organization as a consequence of little perturbations. In this paper we investigate the stability of the calorimetric behaviour of EDS with a high ionic force, due to the presence of the sodium chloride electrolyte. We measured the excess heats of mixing of EDS with basic solutions, both with and without a high concentration of NaCl, and compared the results. In particular, we explored these concentrations: 0.5 and 1Mmol kg⁻¹). The analysis of the experimental results shows that the calorimetric response of the EDS is stable when they are in a concentrated solution of NaCl. That is of great relevance for the eventual pharmacological action of these solutions, since it involves the interaction with fluids of complex chemical composition and high concentration.     

Physical–chemical study of water in contact with a hydrophilic polymer: Nafion

The study detailed in this paper is about the determination of the physical–chemical parameters of water, after keeping it in prolonged contact with the Nafion polymer. The parameters under study are: electrical conductivity, χ (μS cm^?1); heat of mixing with acid (HCl), ΔQ _mix ^HCl (J kg^?1) or basic (NaOH) solutions, ΔQ _mix ^NaOH  (J kg^?1), and pH. χ increases of up to two orders of magnitude, ΔQ _mix ^NaOH  (J kg^?1) is exothermic and increases as the electrical conductivity increases, with a roughly linear trend, up to one order of magnitude. The analogous ΔQ _mix ^HCl  (J kg^?1), on the contrary, is found to be null. The pH is quite acid and shows a very good linear correlation with log χ. The linear correlations hint at a single cause for the variation of the three very different physical–chemical parameters. This complex and hard to rationalize phenomenology, finds a good theoretical support in the work hypothesis of the formation of dissipative structures within the liquid. These are far-from-equilibrium systems outside the paradigm of classical thermodynamics. The work hypothesis of the formation of molecular aggregates of water molecules (dissipative structures, aqueous nanostructures, clusters, coherence domains, etc.) is shared with two other aqueous systems obtained with different preparation protocols, so we briefly recall them here: (1) EDS (extremely diluted solutions): obtained through an iterative process of successive dilutions and agitations. (2) IFW (iteratively filtered water): obtained through an iterative process of successive filtrations through sintered glass filters. (3) INW (iteratively nafionized water): obtained through an iterative process of successive drying and wetting of the Nafion polymer. Each protocol produces water exhibiting its own peculiarities, to the point that they can be considered different, albeit with the common element of a variation of the super-molecular structure of the water solvent. The physical–chemical properties of these perturbed waters cannot be framed by the paradigm of classical thermodynamics, but rather require the use of the thermodynamics of systems far from the equilibrium and of irreversible processes.     

New Physico-Chemical Properties of Extremely Diluted Solutions. Electromotive Force Measurements of Galvanic Cells Sensible to the Activity of NaCl at 25 °C

The mean ionic activity coefficients for sodium chloride in the NaCl+H₂O binary system have been experimentally determined at 298.15 K, from electromotive force measurements of the cell:

Physico-chemical properties of aqueous extremely diluted solutions in relation to ageing

An extensive study has been carried out on aqueous ‘extremely diluted solutions’ (EDS). The employed experimental methodologies were well established physico-chemical techniques: flux calorimetry, conductometry, pH-metry, e.m.f. of suitable galvanic cell. The obtained results show that the preparation procedure significantly alters the physico-chemical behaviour of such solutions. Moreover, the analysis of the experimental data vs. the ‘arrow of time’ turned out to be astonishingly important. In fact some measured physico-chemical parameters evolve with time. Some experimentally measurable physico-chemical properties of the solvent water were largely affected by both time and the ‘life path’ of the samples. In particular, we evidenced two new experimental phenomena characterizing the EDS: the presence of a series of maximums in the measured electrical conductivity vs. the sample age; the dependence of said maximums on the volume of the EDS during its ageing. All of these new experimental results clearly suggest the presence of an extended and ‘ordered’ dynamics involving the whole of the water molecules in the liquid. A temporal evolution, featuring three maximums in the course of four years of ageing and the dependence on the ageing volumes do not fit the framework of classical thermodynamics. It therefore seems appropriate to interpret these phenomena on the basis of the thermodynamics of dissipative structures, which are far from equilibrium systems.     

Conductometric and calorimetric studies of the serially diluted and agitated solutions

We systematically analysed the experimental data related to the specific conductivities and heats in excess of several serially diluted and agitated solutions (SDA for short). For all of the analysed samples, we found that both the excess conductivity, χ^E (μS cm⁻¹), and excess heat, Q _mix^E (J kg⁻¹), varied with the age of the sample (up to 2 years of ageing). Furthermore, we found that after a certain period of ageing, small volume samples exhibited a much higher excess than large volume ones. The results we report in this paper are the product of a systematic study, during which we operated on known and constant volumes across the life of the samples. The incidence of volume on χ^E and Q _mix^E turned out to be overwhelming when compared with that of time. The temporal evolution of the smaller samples was found significantly higher than that of the larger volume ones. A careful numerical analysis of the results uncovered an extraordinary and unexpected correlation, of exponential kind, between the excess parameters and the volume of the solution in the container. As for the temporal evolution of these systems, we found that the measured excess heats and conductivity often reach a maximum. That led us to the conclusion that the temporal evolution of the physico-chemical parameters is not caused by the slow process of equilibrium attainment; on the contrary, these systems are far from equilibrium systems, dissipative structures, whose experimental behaviour is certainly due to the variation of the super-molecular structure of the solvent, water. The agitation phase during the preparation could be the trigger for the formation of dissipative structures and the emergence of the novel behaviour. We put forth a simple rationalizing hypothesis, based on the general idea of water as an auto-organizing system that, when elicited by even small perturbations, can enter a far from equilibrium state, sustained by the dissipation of the electromagnetic energy coming from the environment. (Dissipative Structures).     

Concentration dependences of the physicochemical properties of a water–acetone system

Concentration dependences of the UV spectrum, refractive index, specific electrical conductivity, boiling point, pH, surface tension, and heats of dissolution of a water–acetone system on the amount of acetone in the water are studied. It is found that the reversible protolytic interaction of the components occurs in all such solutions, resulting in the formation of hydroxyl and acetonium ions. It is shown that shifts of the equilibrium between the molecules and ions in the solution leads to extreme changes in their electrical properties. It is concluded that the formation of acetone solutions of water is accompanied by heat absorption, while the formation of aqueous solutions of acetone is accompanied by heat release.     

Thermal properties of ternary systems: The calculation of the standard enthalpy of solution for compounds in binary mixtures

An equation free of fitting parameters is proposed for calculating the standard heats of solution for compounds in nonaqueous binary mixtures. The parameters of the equation are the standard heats of solution of a compound in the components of the mixed solvent. Nonlinear ΔH ⁰(x) trends are reconstructed for solutions of water in i-PrOH + MeOH and MeCN + MeOH, t-BuOH in MeCN + MeOH, squalane in CHCl₃ + CCl₄ and C₆H₆ + CHCl₃, and hexadecane in MeOH + i-Pr₂O and in mixtures of butyl acetate, ethyl acetate, and 1,4-dioxane with 1-octanol. The standard heats of solutions are calculated for water in alcohol + alcohol, alcohol + aprotic solvent, and aprotic solvent + aprotic solvent mixtures     

Surface Modification of Carbon Nanotube by Poly(ethylene glycol) for the Preparation of Poly(vinyl alcohol) Nanocomposite

Herein, PEGylated multi-walled carbon nanotube (MWNT) was prepared for the successive fabrication of poly(vinyl alcohol) PVA/MWNT nanocomposite film by solution casting. The surface modified MWNT showed a good colloidal stability in a polar solvent, i.e., water. Also, the PEGylated MWNT had an improved dispersion stability in aqueous PVA solution. The mixture of PEGylated MWNT and PVA dissolved in water was film casted and the dispersion uniformity and corresponding improvement of electrical conductivity were investigated. The electrical conductivity of PVA/modified MWNT composite film was three-fold higher than that of PVA/pristine MWNT composite film due to the much improved distribution uniformity of modified MWNT in PVA matrix.     

On the stability of extremely diluted solutions to temperature

Conductometric and calorimetric titrations of extremely diluted solutions (EDS) were performed by adding HCl or NaOH solutions. The aim of this work was to confirm the hypothesised presence of molecular aggregates of water molecules in EDS stored for 15 months at 5 different temperatures. Conductometric and calorimetric measurements on the EDS samples revealed significant differences compared to the solvent. The experimental data can be interpreted as indicating a favourable interaction between the H₃O⁺ and OH^? ions and the dissipative structures, leading to the formation of complexes between the two ions deriving from probes and the molecular aggregates of water molecules. These results suggest that storing EDS at different temperatures does not alter the non-equilibrium changes in the supramolecular structure of water in the studied solutions.     

Calorimetric study of the enthalpies of solution of methyl iodides of dimethylamino grosshemin and diethylamino grosshemin in water and evaluation of the thermodynamic properties of their analogues

The method of isothermal calorimetry at dilutions (moles salt/moles water) of 1:9000, 1:18000, and 1:36000 was applied to study the heats of solution of methyl iodides of dimethyl-and diethylamino grosshemin. The data obtained were used to calculate the standard enthalpies of solution of C₁₈H₂₈O₄NI and C₂₀H₃₂O₄NI in an infinitely diluted (standard) aqueous solution. The heats of combustion and melting of C₁₈H₂₈O₄NI and C₂₀H₃₂O₄NI were estimated. The experimental and calculational techniques were combined to calculate the standard heats of formation of methyl iodides of dimethyl-and diethylamino grosshemin and their 66 analogues.     

Limiting equivalent electrical conductivity of inorganic salt solutions and dielectric properties of a polar solvent

A relation has been found to exist between the limiting equivalent electrical conductivity of inorganic salt solutions, viscosity, temperature, and dielectric properties of the solvent. As temperature rises, the limiting equivalent electrical conductivity of aqueous solution of an inorganic salt has been shown to increase in direct proportion to the ratio of the dielectric permittivity to the dipole dielectric relaxation time, i.e., the limiting high-frequency electrical conductivity of the polar solvent. Expressions have been derived to be used in ascertaining the limiting equivalent electrical conductivities of inorganic salt solutions proceeding from the dielectric properties of the solvent.     

A thermodynamic characterization of aqueous nanostructures of water molecules formed by prolonged contact with the hydrophilic polymer Nafion

This work investigates the physicochemical alterations of water perturbed by prolonged contact with the hydrophilic polymer Nafion, referred to as iteratively nafionized water (INW). The parameters measured are: electrical conductivity, χ μS cm^?1, heat of mixing with basic sodium hydroxide (NaOH) solutions, ΔQ _NaOH ^mix  J kg^?1, and pH. The results indicate that supramolecular aggregates of water molecules form after prolonged contact with a Nafion surface. Analytical determination by ion chromatography allows us to exclude the role of contaminants. This suggests that water may possess an exceptional self-organization capability triggered by the contact with a hydrophilic surface. Conductometric, pH-metric, and calorimetric titrations of INW were performed by the addition of NaOH solutions to determine the concentration of the aqueous nanostructures, via conductometric and pH-metric titration with NaOH solutions. Thermodynamic parameters were determined via calorimetric titration, for the process of formation of complexes between the nanostructures and the base used.     

Determination of sulphur in uranium matrix by total reflection X-ray fluorescence spectrometry

The possibility of sulphur determination in uranium matrix by total reflection x-ray fluorescence spectrometry (TXRF) has been studied. Calibration solutions and samples of sulphur in uranium matrix were prepared by mixing uranium in form of a standard uranyl nitrate solution and sulphur in the form of Na₂SO₄ standard solution, prepared by dissolving Na₂SO₄ in Milli-Q water. For major element analysis of sulphur, it was determined without separation of uranium whereas for the trace level determinations, uranium was first separated by solvent extraction using 30% tri-n-butyl phosphate (TBP) in dodecane as an extractant. In order to countercheck the TXRF results, a few samples of Rb₂U(SO₄)₃, a chemical assay standard for uranium, were diluted to different dilutions and sulphur content in these solutions were determined. The TXRF determined results for trace determinations of sulphur in these diluted solutions were counterchecked after addition of another uranium solution, so that sulphur is at trace level compared to uranium, separating uranium from these solution mixtures using TBP extraction and determining sulphur in aqueous phase by TXRF. For such TXRF determinations, Co was used as internal standard and W Lα was used as excitation source. The precision and accuracy of the method was assessed for trace and major element determinations and was found to be better than 8% (1σ RSD) and 15% at a concentration level of 1 μg/mL of sulphur measured in solutions whereas for Rb₂U(SO₄)₃, these values were found to be better than 4 and 13%, respectively.