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Water structure and behavior

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H2O

 

Magnetic and Electric Effects on Water


Water, being dipolar, can be partly aligned by an electric field and this may be easily shown by the movement of a stream of water by an electrostatic source [163]. Very high field strengths (5 x 109 V m-1) are required to reorient water in ice such that freezing is inhibited [251]. Even partial alignment of the water molecules with the electric field will cause pre-existing hydrogen bonding to become bent or broken. The balance between hydrogen bonding and van der Waals attractions is thus biased towards van der Waals attractions giving rise to less cyclic hydrogen bonded clustering.

Water is diamagnetic and may be levitated in very high magnetic fields (10 T, cf. Earth's magnetic field 30 mT) [170]. Lower magnetic fields (0.2 T) have been shown, in simulations, to increase the number of monomer water molecules [192] but, rather surprisingly, they increase the tetrahedrality at the same time. They may also assist clathrate formation [485]. The increase in refractive index with magnetic field has been attributed to increased hydrogen bond strength [647]. These effects are consistent with the magnetic fields weakening the van der Waals bonding between the water moleculesa and the water molecules being more tightly bound, due to the magnetic field reducing the thermal motion of the inherent charges by generating dampening forces [703]. Due to the fine balance between the conflicting hydrogen bonding and non-bonded interactions in water clusters, any such weakening of the van der Waals attraction leads to a further strengthening of the hydrogen bonding and greater cyclic hydrogen bonded clustering. This effect of the magnetic field on the hydrogen bonding has been further supported by the rise in the melting point of H2O (5.6 mK at 6 T) and D2O (21.8 mK at 6 T) [703] indicating greater ordering (lower entropy) in the liquid water within a magnetic field. Far greater effects on contact angle and Raman bands have been shown to occur using strong magnetic fields (6 T) when the water contains dissolved oxygen (but not without the oxygen), indicating effects due to greater clathrate-type water formation [970].

Thus it appears that electric and magnetic fields have opposite effects on water clustering. Static magnetic effects have been shown to cause an increase in the ordered structure of water formed around hydrophobic molecules and colloids [106], as shown by the increase in fluorescence of dissolved probes [108]. This reinforces the view that it is the movement through a magnetic field, and it associated electromagnetic effect, that is important for disrupting the hydrogen bonding. Such fields can also increase the evaporation rate of water and the dissolution rate of oxygen but cannot, despite claims by certain expensive water preparations, increase the amount of oxygen dissolved in water above its established, and rather low, equilibrium concentration [176]. Magnetic fields can also increase proton spin relaxation [623], which may speed up some reactions dependent on proton transfer.

Belief in whether or not magnetic or electromagnetic fields can have any more permanent effect on water, and solutions, depends on the presence of a working hypothesis for their mode of action (see also homeopathy). Such hypotheses are emerging. On a cautionary note however, many studies either do not treat results with proper statistical rigor or do not use relevant 'untreated' material for comparison.

Unstructured water with fewer hydrogen bonds is a more reactive environment [286], as exemplified by the enhanced reactivity of supercritical water.b An open, more hydrogen-bonded network structure slows reactions due to its increased viscosity, reduced diffusivities and the less active participation of water molecules. Any factors that reduce water-water hydrogen bonding and hydrogen bond strength, such as electric fields, should encourage reactivity. Water clusters (even with random arrangements) have equal hydrogen bonding in all directions. As such, electric or electromagnetic fields that attempt to reorient the water molecules should necessitate the breakage of some hydrogen bonds; e.g. electric fields have been reported to halve the mean water cluster size as measured by 17O-NMR [111] (see also 'declustered' water). Electromagnetic radiation (e.g. microwave) has been shown to exert its effect primarily through the electrical rather than magnetic effect [455]. The increased hydration ability of water in electromagnetic fields has been demonstrated by the dissociation of an enzyme dimer (electric eel acetylcholinesterase), leading to gel formation, due to the microwave radiation from a mobile phone [714]. The resultant aqueous restructuring caused by such processes may be kinetically stable.

Pure water is a poor conductor of electricity but is not a perfect insulator as it always contains ions due to self-ionization. Passage of an electric current causes electrolysis, producing O2 at the anode and H2 at the cathode. At metallic electrodes, even quite low voltages can have impressive effects on the orientation of the water molecules and the positioning of ions [375].c A negative potential of -0.23 V orients water hydrogen atoms towards the electrode whereas +0.52 V reverses this; both causing some hydrogen bond breakage and localized density increase.d Ions are attracted or repelled dependent on their charge. Similar orientations may take place at the surface of minerals containing alternating positive and negative charges such that a solid (static and non-exchangeable) water layer has been reported at the surface of highly polar metal oxides, (e.g. TiO2) and an ambient temperature single layer ice (with all the donor hydrogen bonds oriented towards each other or the silica surface oxygen atoms) is found, using modeling, on the surface of hydrophilic fully hydroxylated silica ([701], called ice tesselation), which may explain the many layers of structured water found at the surfaces of complex silicates. Thus, a high-voltage electric field (333 kV m-1) has been shown to raise the water activity in bread dough, so ensuring a more efficient hydration of the gluten [331] and treatment of water with magnetic fields of about one Tesla increases the strength of mortar due to its greater hydration [426]. Rather unexpectedly, such electric fields (~1 MV m-1) apparently increase water's surface tension by about 2% [680].e High interfacial fields (E > 109 V m-1) at electrode (or charged) surfaces can cause a phase transition with an ordered layering of water at high densities similar to ice X [420], whereas lower fields (E =106 V m-1) may cause lower density freezing transitions at room temperature [873]. High fields (E ~109 V m-1) might also be found (perhaps surprisingly) at the surface of hydrophilic molecules where caused by the partial charges on the atoms and the small distances between the surface and first hydration layer. High fields affect hydrogen bonding in an anisotropic manner, hydrogen bonds being strengthened along the field but weakened orthogonal to the field [582]. At low fields, however, both translational and rotational motions may be reduced. Electric fields also lower the dielectric constant of the water [616], due to the resultant partial or complete destruction of the hydrogen-bonded network. Consequentially, the solubility properties of the water will change in the presence of such fields and may result in the concentration of dissolved gasses and hydrophobic molecules at surfaces followed by reaction (e.g. due to reactive singlet oxygen (1O2) or free radical formation such as OH) or phase changes (e.g. formation of flattish surface nanobubbles [506]). Such changes can clearly result in effects lasting for a considerable time, giving rise to claims for 'memory' effects. One of the curious facts, concerning reports of the effects of magnets and electromagnetic radiation on the properties of water, is the long lifetime these effects seem to have (e.g. [757]). This should not be so surprising, however, as it can take several days for the effects, of the addition of salts to water, to finally stop oscillating [4]. Also, there is evidence that water structuring in still deaerated pure water increases over a period of a day or two [509], clathrates may persist metastably in water [485], water restructuring after infrared radiation persists for more than a day [730], and water photoluminescence (possibly due to impurities at gas/liquid interfaces [800b]) changes over a period of days [801]. Permanent changes to the structure of water are reported following exposure to resonant RLC (resistance inductance capacitance) circuits [927]. The effects, however, are small and poorly reproducible and, as with some of the other studies mentioned here, should be viewed with the possibility that pathological science is at work.

In addition to the breakage of hydrogen bonds electromagnetic fields may perturb in the gas/liquid interface and produce reactive oxygen species [110]. Changes in hydrogen bonding may effect carbon dioxide hydration resulting in pH changes. Thus the role of dissolved gas in water chemistry is likely to be more important than commonly realized [459]; particularly as the formation of nanobubbles [506] containing just a few hundred or less molecules of gas, the stability of larger bubbles (~300 nm diameter) detected by light scattering [800a] and nanobubble coating of hydrophobic surfaces [803] have all been recently described. Reinforcement of this view comes from the effect of magnetized water on ceramic manufacture [601] and out-gassing experiments that apparently result in the loss of magnetic and electromagnetic effects [110, 800a] or photoluminescent effects [800b]. Gas accumulating at hydrophobic surfaces [459b] promotes the hydrophobic effect and low-density water formation. The accumulated gas molecules at such hydrophobic surfaces becomes supersaturating when electromagnetic effects disrupt this surface low-density water. An interesting (and possibly related) 'memory of water' phenomena is the effect of water, previously exposed to weak electromagnetic signals, on the distinctive patterns and handedness of colonies of certain bacteria [971]. Here, the water retains the effect for at least 20 minutes after exposure to the field.

Recently, there has been some debate over 'digital biology'; a proposal from Jacques Benveniste (leader of the team that produced the controversial homeopathy paper) that 'specific molecular signals in the audio range' (hypothetically the 'beat' frequencies of water's infrared vibrations) may be heard, collected, transmitted (e.g. by phone) and amplified to similarly affect other water molecules at a receiver [134]. This unlikely idea is generally thought highly implausible. The data has, however, reportedly been independently confirmed but this has not yet been published (which may be rather problematic in the present skeptical climate). Note that experimental confirmation of the phenomenon may not necessarily confirm the proposed mechanism. Rather interestingly, however, electromagnetic emission has been detected during the freezing of supercooled water [297] due to negative charging of the solid surface at the interface caused by surface ionization of water molecules followed by preferential loss of hydrogen ions [462]; a consequence, perhaps, of the Costa Ribeiro effect [551]. It is not unreasonable, therefore, that similar effects may occur during changes in the structuring of liquid water. Also, it has been reported that microwave frequencies can also give rise to signals audible to radar operators [356].

If electromagnetic effects do indeed influence the degree of structuring in water, then it is clear that they may have an effect on health. The biological effects of microwaves, for example, have generally been analyzed in terms of their very small heating effects. However, it should be recognized that there might be significant non-thermal effects (e.g. [714]) due to the imposed re-orientation of water at the surfaces of biomolecular structures such as membranes [356]. Similar effects on membranes have been proposed to occur due to magnetic fields [657]. Additionally as low-frequency, low level alternating electric fields have been found to affect the electrical conductivity of pure water [358], the effects of living near power cables and microwave towers should, perhaps, not be thought harmless just because no theory for harm has been formally recognized. Even variations in the geomagnetic field may have some long-term exposure effects.

 

a This effect has been demonstrated in weakly bound van der Waals complexes as due to the coupling between magnetic-field induced energy levels (Zeeman levels) of the molecular orbitals [659]. [Back]

b Note that this may not extend to conditions of much-reduced hydrogen bonding. At close to critical and supercritical conditions, water molecules may become less reactive than expected with temperature increase due to the loss of hydrogen bonding causing consequential loss of the 'cage' effect, which encourages reactions within the 'cage', and reduced polarization activation. [Back]

c Note that the electric field strength across the surface monolayer of water molecules may be of the order of 1010 V m-1 for just a few volts applied potential. [Back]

d The binding of water molecules to uncharged metal surfaces depends on the nature of the metal. On a platinum Pt(111) surface, half the water molecules form PtOH2 links with the other half forming PtH-OH bonds due to the balance between PtH hydrogen bond formation and H-O bond weakening. Other metal surfaces may prefer one or the other water orientation or cause partial dissociation of the protons dependent on their proton affinity [523]. [Back]

e Electric and magnetic fields lower the surface tensions of natural water by up to 8% [735]. However, it has been noted elewhere that surface tension measurements are too sensitive to impurities to provide reliable data [979]. [Back]

 

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This page was last updated by Martin Chaplin
on 10 March, 2006