Ethylene Oxide-propylene Oxide Block Copolymers Research Articles

Nanoencapsulation-based fabrication of eco-friendly pH-responsive pyraclostrobin formulations with enhanced photostability and adhesion to leaves

The development of pesticide-loaded nanocapsules responding to environmental stimuli holds great promise for sustainable disease control and may help to reduce pesticide usage while making it more efficient. Herein, pH-responsive nanocapsules containing pyraclostrobin (Pyr) were constructed by the rapid interfacial assembly of tannic acid (TA), ethylene oxide-propylene oxide block copolymer, and Cu2+ ions using a fine reversed-phase emulsion as a template. Under acidic conditions similar to those caused by Rhizoctonia solani infestation, these nanocapsules released Pyr to achieve its intelligent delivery and, hence, efficient R. solani control. Nanoencapsulation significantly increased the photostability of Pyr, and the half-life increased by 10 times compared with the Pyr-technical (Pyr-TC). In addition, the introduction of TA enhanced its spreading performance and rainfall resistance in crops, and contact angle drops to 2.2° ± 0.1° in 100 s. Its toxicity to non-target organisms (Daphnia magna and humans) was reduced. The fabricated nanocapsules exhibited a high antifungal activity superior to that of commercially available agents and exerted no significant adverse effects on crop growth and soil microbial communities. Thus, our work highlights the potential of nanoencapsulation for the intelligent delivery of fungicides to target crops, thus providing an effective strategy for improving the efficiency of pesticide usage and promoting sustainable pesticide development.

Thermoreversible Growth of Viscosity upon Heating of the Aqueous Solutions of Ethylene Oxide-Propylene Oxide Block Copolymers Unaccompanied by Gelation

Thermoreversible Growth of Viscosity upon Heating of the Aqueous Solutions of Ethylene Oxide-Propylene Oxide Block Copolymers Unaccompanied by Gelation

Polymeric composites of 1,2,4-thiadiazole: solubility, dissolution and permeability assay

The derivative of 1,2,4-thiadiazole (TDZ) can be considered as a perspective agent for the Alzheimer’s disease prevention. Due to a highly lipophilic character, the compound reveals good membrane permeability properties and poor solubility in aqueous media. In order to solve this problem, water-soluble biodegradable polymers: PEG 6000 (PEG), PVP K29-30 (PVP) and linear (A–B–A type) ethylene oxide-propylene oxide block copolymer Pluronic F127 (F127) were used in the present investigation to obtain binary and ternary TDZ composites (solid dispersions) with improved solubility and dissolution rate. Composites were prepared by a mechanical grinding procedure. Differential scanning calorimetry and FTIR spectroscopy were used to characterize the obtained samples. The interaction of TDZ with PVP after the grinding procedure was revealed. Shake-flask method was applied to measure the solubility of the composites. A dramatical increase in the solubility was shown for the solid dispersion with F127 above the critical micelle concentration. The dissolution behavior was studied with the help of the basket method at pH 1.2 and pH 6.8. The dissolution of TDZ/polymer solid dispersions was substantially accelerated as compared to pure TDZ and physical mixtures. The dissolution mechanism was estimated through the Korsmeyer–Peppas model equation. Franz diffusion cell and new Permeapad™ barrier were applied for the permeability assay. The permeability of TDZ in solid dispersions through the Permeapad™ barrier was shown to decrease in comparison with the pure TDZ. It was concluded that composites with PEG, PVP and F127 are an effective tool for increasing the solubility and dissolution of 1,2,4-thiadiazole derivative.

Effects of head group and counter-ion variation in cationic surfactants on the microstructures of EO-PO block copolymer micelles

This study reports the effect of several cationic surfactants namely C16TABr,C16TPPBr, C16TBPBr, C16PyBr, C16TACl and C16TATs, each with 16C long alkyl side chain but different counterions and head groups on the micellar behavior of an ethylene oxide-propylene oxide (EO-PO) linear triblock copolymer, Pluronic® 103 from cloud point (CP), dynamic light scattering (DLS) and small angle neutron scattering (SANS) measurements. The solubilizing capacity of the mixed system was also checked for a poorly water soluble drug quercetin (QN). We show that cationic surfactants in the aqueous copolymeric system enhanced the surface charge density on P103 micelles. Eventually, increase in repulsion leads to micellar break down. This was manifested as reduction in micelle size and upshifted CP. However, the mixed system offered significant increase in solubilization of QN. The results from the present study may be helpful in developing a basic understanding to choose appropriate cationic surfactants for the desired applications and to attain preferred micellar dimensions and morphology.

A Comparative Study on Micellar and Solubilizing Behavior of Three EO-PO Based Star Block Copolymers Varying in Hydrophobicity and Their Application for the In Vitro Release of Anticancer Drugs.

The temperature and pH dependent self-assembly of three star shaped ethylene oxide-propylene oxide (EO-PO) block copolymers (Tetronics® 304, 904 and 908) with widely different hydrophobicity was examined in aqueous solutions. Physico-chemical methods viz. viscosity, cloud point, solubilization along with thermal, scattering and spectral techniques shows strongly temperature and salt dependent solution behavior. T304 possessing low molecular weight did not form micelles; moderately hydrophilic T904 remained as micelles at ambient temperature and showed micellar growth while very hydrophilic T908 formed micelles at elevated temperatures. The surface activity/micellization/solubilization power was favored in the presence of salt. The copolymers turn more hydrophilic in acidic pH due to protonation of central ethylene diamine moiety that hinders micelle formation. The solubilization of a model insoluble azo dye 1-(o-Tolylazo)-2-naphthol (Orange OT) and hydrophobic drugs (quercetin and curcumin) for copolymer solutions in aqueous and salt solutions are also reported. Among the three copolymers, T904 showed maximum solubility of dye and drugs, hence the in vitro release of drugs from T904 micelles was estimated and the effect on cytotoxicity of loading the drugs in T904 micelles was compared with the cytotoxicity of free drugs on the CHO-K1 cells. The results from the present work provide a better insight in selection of Tetronics® for their application in different therapeutic applications.

Modulating effect of different biomolecules and other additives on cloud point and aggregation of amphiphilic linear and starblock copolymer

Non-ionic surfactants based on ethylene oxide-propylene oxide (EO-PO) block copolymers find applications in various industries including pharmaceutics, cosmetics, cleaning and dispersion sciences. This work shows the comparison among the clouding behaviour of two moderately hydrophobic EO-PO block copolymers viz. linear triblock Pluronic® P104 and starblock Tetronic® T1304 (henceforth mentioned as P104 and T1304), showing the effect of several additives viz. inorganic salts (NaCl, NaF, NaBr, NaI, NaCNS, Na2SO4, NaNO3), sugars (dextrose, sucrose, maltose, mannitol, sorbitol), amino acids (glycine, alanine, valine, serine, lysine, leucine, histidine, glutamine), ureas [urea, thiourea, N-methylurea (MMU), N,N′-dimethylurea (DMU), N, N, N′ N′-tetramethylurea (TMU), phenylurea], alcohols [ethanol, 1-butanol, 1-hexanol, 1-octanol, trifluoroethanol (TFE)], diols (ethylene glycol, 1,4-butanediol, 1,6-hexanediol,1,8-octanediol), water soluble polymers [polyvinyl alcohol (PVA 160K, PVA 49K), polyethylene glycol (PEG 300K, PEG 8K), polyvinylpyrrolidone (PVP 55K), and alkyl methylimidazolium ionic liquids [1-butyl-3-methylimidazolium chloride (C4mimCl), 1-butyl-3-methyl imidazolium hexafluorophosphate (C4mimPF6), 1-butyl-3-methyl imidazolium trifluoromethanesulfonate (C4mimCF3SO3), 1-methyl-3-octylimidazolium chloride (C8mimCl), 1-decyl-3-methylimidazolium chloride (C10mimCl)]. The effect of these additives is described in terms of their molecular characteristics and interaction with water or the copolymer. Both, hydrophobicity and structural properties of additives play important roles in the observed cloud point variation. Dynamic light scattering results on apparent micelle size for selected system are also reported. Tuning of phase and aggregation behaviour of ethylene oxide based non-ionic amphiphiles is of industrial and biomedical importance.

Quantifying Binding of Ethylene Oxide-Propylene Oxide Block Copolymers with Lipid Bilayers.

Block copolymers composed of poly(ethylene oxide) (PEO) and poly(propylene oxide) (PPO) have been widely used in cell membrane stabilization and permeabilization. To explore the mechanism of interaction between PPO-PEO block copolymers and lipid membranes, we have investigated how polymer structure influences the polymer-lipid bilayer association by varying the overall molecular weight, the hydrophobic and hydrophilic block lengths, and the end-group structure systematically, using 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC) unilamellar liposomes as model membranes. Pulsed-field-gradient NMR (PFG-NMR) was employed to probe polymer diffusion in the absence and presence of liposomes. The echo decay curves of free polymers in the absence of liposomes are single exponentials, indicative of simple translational diffusion, while in the presence of liposomes, the decays are biexponential, with the slower decay corresponding to polymers bound to liposomes. The binding percentage of polymer to the liposome was quantified by fitting the echo decay curves to a biexponential model. The NMR experiments show that increasing the total molecular weight and hydrophobicity of the polymer can significantly enhance the polymer-lipid bilayer association, as the binding percentage and liposome surface coverage both increase. We hypothesize that the hydrophobic PPO block inserts into the lipid bilayer due to the fact that little molecular exchange between bound and free polymers occurs on the time scale of the diffusion experiments. Additionally, as polymer concentration increases, the liposome surface coverage increases and approaches a limit. These results demonstrate that PFG-NMR is a simple yet powerful method to quantify interactions between polymers and lipid bilayers.

Tuning the self-assembly of EO-PO block copolymers and quercetin solubilization in the presence of some common pharmacuetical excipients: A comparative study on a linear triblock and a starblock copolymer

Here we report, the effect of biologically important additives such as glucose, glycine, sodium chloride, urea and ethanol on the clouding and micellar behaviour of two commercially available ethylene oxide-propylene oxide (EO-PO) block copolymers (one linear triblock, Pluronic® P104 and other branched, starblock Tetronic® T1304) in aqueous environment. The cloud point (CP), viscosity, and dynamic light scattering (DLS) were measured. The solubilization of poorly water soluble drug, quercetin (QN) was also checked for the copolymer micelles in the presence of these additives using UV–visible spectroscopy. These additives depending upon their structure either decrease or increase CP and hydrodynamic diameter (Dh). Salt, glucose and glycine favoured micellization while urea and ethanol showed opposite behaviour. Markedly enhanced solubilization of QN was observed by the copolymer micelles which further improved in the presence of salt, glucose and glycine but decreased in the presence of ethanol and urea. The conclusions derived from this work will be highly useful in optimizing the performance of the copolymers in different pharmaceutical applications and in drug delivery systems as drug carriers.

Systematic characterization of Pluronic® micelles and their application for solubilization and in vitro release of some hydrophobic anticancer drugs

Abstract The utilization of polymeric micelles in oncology in the last few decades has progressed by leaps and bounds from the advances in polymer chemistry, in drug formulation and delivery (in vitro and in vivo biological models). Commercially available linear (A-B-A type) ethylene oxide-propylene oxide (EO-PO) block copolymers, Pluronics® have acquired added attention by virtue of their capability to load therapeutics, execute the delivery of the consignment to the site of action, improve the pharmacokinetics of the loaded drugs and reduce off-target cytotoxicity. The size of the hydrophobic (middle) and hydrophilic (end) blocks in copolymer molecule plays a decisive role for the drug loading capabilities. Hence, with this objective, we have examined the role of six different Pluronics® with varying molecular characteristics in the solubilization of three widely used hydrophobic anticancer drugs genistein (GEN), paclitaxel (PCL), and quercetin (QCT). Stable micelles (apparent hydrodynamic diameter ~ 15–20nm) form in case of moderately hydrophobic copolymers viz. P103 and P123 at ambient temperature while very hydrophilic F88 forms micelles at elevated temperatures due to much higher critical micelle temperature (CMT). All the three drugs showed enhanced solubility in copolymer micelles with the increase in temperature and salt concentration. The drug loading, stability and in vitro release profiles from the micelles were examined using reversed phase HPLC. Release profile demonstrated slower and sustained release. The in vitro cytotoxicity of the drug loaded micelles was investigated on MCF-7 breast cancer cells which showed higher anticancer activity as compared to free drugs. PCL loaded P123 micelles exhibited the best anticancer activity. The results of the current work will be highly commodious for the application of Pluronics® in anticancer therapeutics.

A multitechnique approach on adsorption, self-assembly and quercetin solubilization by Tetronics® micelles in aqueous solutions modulated by glycine

Ethylene oxide-propylene oxide (EO-PO) block copolymer micelles are useful potential nanoreservoirs for the delivery of hydrophobic drugs. Considering that glycine is an excipient and can favorably affect the surface/micellar behavior and thus improve solubilization power/dispersion stability/wetting characteristics we have reported here studies on aqueous solution behavior of two commercially available branched block copolymers (Tetronics®) with differing hydrophobicities namely Tetronics® 1307 and 1304, hereafter referred as T1307 and T1304, in the presence of glycine. Steady state fluorescence studies using pyrene as a probe, equilibrium and dynamic surface tension measurements, wetting and dispersion stability studies of Teflon (polytetrafluoroethylene; PTFE) and solubilization studies of a hydrophobic antioxidant/anticancer drug quercetin (QN) have been examined. The cloud point (CP) and critical micelle temperature (CMT) decrease while micelle hydrodynamic size (Dh) increases with the addition of glycine as well as on loading of the drug in the micelles. Water penetration through packed PTFE powder and dynamic surface tension confirm the enhanced micellization process for aqueous Tetronic® solutions in presence of glycine and accordingly restricted diffusion for the surfactant molecules towards air-water and PTFE-water interface. The contact angles for Tetronic® solutions in presence of glycine indicate moderate decrease. The pressure-area curves of the copolymers in water and glycine solutions were also constructed. Surface and micellar properties of copolymers are markedly altered in the presence of glycine and can be tuned for use of these nanocarriers in delivery systems.

Thermal and scattering studies of Tetronic® 1304 micelles in the presence of industrially important glycols, their oligomers, cellosolves, carbitols, ethers and esters

The influence of different glycol additives on the phase behaviour and micellar characteristics of a moderately hydrophobic ethylene oxide-propylene oxide(EO-PO) star block copolymer Tetronic®1304 (hereafter written as T1304) has been investigated by cloud point (CP), viscosity, high sensitivity differential scanning calorimetry (HSDSC), dynamic light scattering (DLS) and small angle neutron scattering (SANS). Glycol additives are commonly used in several industrial and pharmaceutical applications in the presence of these biocompatible, linear and branched EO-PO block copolymers functioning as dispersants, emulsifiers, detergents, defoaming agents and vehicles in pharmaceutical applications. Hence, it is essential to understand the behavior of star block copolymers in their presence (glycol additives) to optimize the performance for applications in diverse areas.In the case of short chain glycols/ethers/cyclic ethers an increase in CP, critical micelle temperature (CMT), hydrodynamic diameter (Dh) has been observed while aggregation number (Nagg) and relative viscosity decreases indicating demicellization. On the other hand, the long chain glycol ethers/aryl ethers/esters promote micellization with an increase in Nagg, micelle size, relative viscosity and decreased CMT. The influence on the micellar characteristics of T1304 is mainly dominated by the hydrophobicity and locus of solubilization of the glycol additives. The morphology of the star block copolymers can thus be customized using different glycol additives for particular applications. The information from this work will be highly lucrative for the industrial and therapeutic applications of star block copolymers using commonly used glycols to optimize their performance.

Effects of crosslinking in demulsifiers on their performance

AbstractChemical demulsification is the most widely used method for breaking water‐in‐diluted bitumen emulsions in oil sands processing. In this work, the properties and performance of six ethylene oxide (EO)–propylene oxide (PO) demulsifiers from three families were investigated. The demulsifiers were characterised by their relative solubility number (RSN) and number of EO–PO branches. The results showed that the performance of the demulsifiers is correlated to the starting base compound, number of EO–PO branches, RSN, oil/water interfacial tension (IFT), increase of molecular weight (MW) by incorporation of crosslinks in EO–PO branches and yield stress of underflow. An increase in MW by the incorporation of crosslinks in EO–PO block copolymers decreased the RSN value while improved the dehydration efficiency. Dynamic IFT measurements revealed that the higher adsorption of EO–PO block copolymers at the oil/water interface on crosslinking, which resulted in higher dehydration efficiencies. The yield stress of the underflow increased on crosslinking the EO–PO block copolymers due to the release of more water and solids to the underflow, which increased the number of aggregates present in the underflow, resulting in increased immobility and constriction and higher yield stress.

Interaction between the ionic liquids 1-alkyl-3-methylimidazolium tetrafluoroborate and Pluronic® P103 in aqueous solution: A DLS, SANS and NMR study

The effect of three ionic liquids (ILs) 1-alkyl 3-methyl imidazlolium tetraflouroborates (Cnmim BF4n=4, 6, 8) on micellar solutions of an ethylene oxide-propylene oxide block copolymer (PEO–PPO–PEO), Pluronic® P103 was examined from scattering and NMR techniques. The ILs alter the cloud point and micelle size dependant on their alkyl chain length and the results are discussed in terms of their behavior as cosolvent/cosurfactant. Cloud point data support the hydrogen bonding between the imidazolium cation and P103 while dynamic light scattering (DLS) and small angle neutron scattering (SANS) reveal that presence of ionic liquid is not conducive to the micelle formation of P103. The selective nuclear Overhauser effect (NOESY) indicates that the PPO block of the P103 interacts with the alkyl group of the Cnmim+ cation by hydrophobic interaction. Through this kind of interactions, Cnmim BF4 and P103 can form mixed micelles. This result indicates that the presence of ILs hinders the micelle formation of P103 in solution and promotes P103 to orient at air/water interface.

Characterization and antimicrobial activity of N-methyl-2-pyrrolidone-loaded ethylene oxide-propylene oxide block copolymer thermosensitive gel

The purpose of this study is to investigate the effects of N-methyl-2-pyrrolidone on the thermosensitive properties of aqueous ethylene oxide-propylene oxide block copolymer (Lutrol® F127) system. Due to the aqueous solubility enhancement and biocompatibility, N-methyl-2-pyrrolidone is an interesting solubilizer for the poorly water soluble drugs to be incorporated in the Lutrol® F127 system. Effect of N-methyl-2-pyrrolidone on physicochemical properties of Lutrol® F127 system was investigated using appearance, pH, gelation, gel melting temperature and rheology. The antimicrobial activity of the thermosensitive N-methyl-2-pyrrolidone gel was also tested. Lower N-methyl-2-pyrrolidone amount (≤30%w/w) could shift the sol-gel transition to a lower temperature but the gel-sol transition was shifted to a higher temperature. Higher N-methyl-2-pyrrolidone (≥40%w/w) could shift both sol-gel and gel-sol transitions of the system to a lower temperature. The amount of N-methyl-2-pyrrolidone >60% w/w could reverse the phase of the Lutrol® F127 system to non-newtonian flow at 4° and Newtonian flow at high temperature. Aqueous Lutrol® F127 system containing N-methyl-2-pyrrolidone exhibited antimicrobial activities against Staphylococcus aureus, Escherichia coli and Candida albicans with the N-methyl-2-pyrrolidone in a dose-dependent manner.

Synthesis and Preliminary Demulsification Efficiency Evaluation of New Demulsifiers Based on Fatty Oils

Three raw fatty oils were used as precursors for demulsifiers. The hydrolyzed form of each oil was adducted with maleic anhydride then modified by esterification with polyethylene glycols or ethyleneoxide-propyleneoxide block copolymers. The demulsfication efficiency, coalescence rate, some surface active, thermodynamic properties, and partition coefficient of a selected demulsifier were investigated. The best demulsifier shows 100% demulsification after 19 minutes at 300 ppm. A correlation between demulsification efficiency and rheological properties of the investigated demulsifier was investigated. Also, emulsification kinetics were followed by microscopic photography. A mechanism following coalescence and flocculation of water droplets is proposed.

Liquid chromatography at critical conditions in ternary mobile phases: Gradient elution along the critical line

In ternary mobile phases consisting of acetone, methanol, and water, the retention of PEG on reversed-phase columns is independent on molar mass at certain compositions of the mobile phase. Along this critical adsorption line, the retention of polypropylene glycol varies quite strongly, which can be utilized in the separation of block copolymers. Gradient elution along the critical line allows a baseline separation of all oligomers in polypropylene glycol up to approximately 25 propylene oxide units. The same resolution can be achieved in the separation of ethylene oxide-propylene oxide block copolymers, regardless of the length of the ethylene oxide block.

Water activity of aqueous solutions of ethylene oxide-propylene oxide block copolymers and maltodextrins

Abstract - The water activity of aqueous solutions of EO-PO block copolymers of six different molar masses and EO/PO ratios and of maltodextrins of three different molar masses was determined at 298.15 K. The results showed that these aqueous solutions present a negative deviation from Raoult's law. The Flory-Huggins and UNIFAC excess Gibbs energy models were employed to model the experimental data. While a good agreement was obtained with the Flory-Huggins equation, discrepancies were observed when predicting the experimental behavior with the UNIFAC model. The water activities of ternary systems formed by a synthetic polymer, maltodextrin and water were also measured and used to test the predictive capability of both models. Keywords : Water activity; Excess Gibbs energy; Phase equilibrium; Flory-Huggins; UNIFAC. INTRODUCTION The water activity (a w ) of an aqueous solution is the ratio between the fugacity of water in this solution and the fugacity of pure liquid water at the same temperature and pressure. This property is the most directly accessible measure of liquid-phase non-ideality of aqueous solutions of non-volatile solutes, since there are either well documented techniques or electronic devices to accomplish it. Besides its scientific importance, water activity is also related to the stability of foodstuffs, for it represents the amount of water available to microbial or chemical spoilage. In other words, high a

Intermolecular interactions governing solubilization in micelles of poly(alkylene oxide) surfactants

Partition coefficients for 39 low-molecular-mass compounds between water and micelles of an ethylene oxide-propylene oxide block copolymer (Pluronic P85) and the monolauryl ether of poly(ethylene oxide) (Brij 35) have been measured by the methods of fluorescence spectroscopy, fluorescence anisotropy, and dialysis kinetics. The tested compounds include aromatic hydrocarbons, phenols, naphthols, xanthene dyes, anthracycline antibiotics, and porphyrins. The multifactor analysis of the partition coefficients in terms of the linear free-energy relationships has been performed. It has been shown that the H-donating ability of compounds facilitates their solubilization in Pluronic micelles and has no effect on solubilization in micelles of monolauryl ether of poly(ethylene oxide). This difference indicates that, when solubilization occurs in Pluronic micelles, the compounds under study appear in a hydrophobic core composed of poly(propylene oxide) blocks.

Effect of the structure of ethylene oxide-propylene oxide block copolymers on their interaction with biological membranes

Partition coefficients of ethylene oxide-propylene oxide block copolymers between the lipid phase and water have been estimated via equilibrium dialysis. It has been shown that for the triblock copolymer (Pluronic L61), the partition coefficient is 45 ± 9, while for the diblock copolymer (REP), this parameter is as high as 78 ± 17. The effect of the copolymers on the permeation of the charged organic ion carboxyfluorescein across the lecithin bilayer membrane changes in the same direction. Even though the triblock copolymer binding is weaker, it shows a stronger effect on the rate of transbilayer migration of lipids and on the permeation of the uncharged substance (doxorubicin). The incorporation of cholesterol into the membrane decreases its sensitivity to the action of copolymers; however, the character of changes induced by both copolymers remains invariable. The experimental data of this study indicate that the triblock structure of amphiphilic macromolecules is responsible for their higher ability to disturb lipid bilayer membranes.

Improving the Infiltration of Water through Repellent Soils Using Synergistic Surfactant Blends Based on Alkyl Glucosides and Ethylene Oxide-Propylene Oxide Block Copolymers

Abstract Soil water repellency arises as a consequence of initial soil water content and the type of organic matter incorporated into or adsorbed onto the individual soil particles. Water repellent soils create significant agronomic and hydrologic challenges, retarding water infiltration into the soil profile and often rendering entire areas impervious to water penetration. These soils often prevent effective wetting of the rootzone during precipitation or irrigation and lead to increased runoff and leaching of pesticides, fertilizers, and other amendments. Agriculturalists have approached the soil water repellency problem through the use of wetting agent surfactant compositions. The degree of wetting efficacy among surfactant chemistries and formulations has varied significantly. The wetting characteristics of alkyl glucosides and ethylene oxide-propylene block copolymers, two nonionic surfactant classes, were evaluated in the context of improving the infiltration of water through water repellent soil profiles. A laboratory column test was used to measure the initial effectiveness of the wetting agent compositions on synthetically hydrophobized and naturally water repellent soils. A synergistically enhanced wetting rate occurred when the alkyl glucoside to block copolymer ratio was from approximately 6:1 to 0.5:1 by weight, ideally when the ratio was from approximately 4:1 to 0.7:1. Within these ratios, synergism was inversely proportional to the HLB and proportional to the molecular weight of the block copolymer used. This research is the first to demonstrate the promising effects of formulations comprising alkyl glucosides and EO/PO block copolymers on improving the distribution and dynamics of water in repellent soils.