Maximum Detergency Research Articles

Improved cold‐water detergency of malodourous soil correlating with hydrophilic–lipophilic deviation concept

AbstractThe persistence of sebum after low‐water‐temperature washing can contribute to malodor and microbial growth during subsequent use; thus, this work focuses on improved sebum removal. The detergency of sebum at various hydrophobic–lipophilic deviation (HLD) values was performed using 0.1 w/v% C12‐13‐8PO‐SO4Na and C8‐4PO‐1EO‐SO4Na at 1:1 molar ratio. The detergency of synthetic sebum on 87/13 polyester/spandex was relatively poor (70% removal) at HLD = 0. Various additives (heptanol, dipropylene glycol n‐butyl ether, decyltrimethyl ammonium bromide or sodium benzoate) were explored and it was found that none of them could facilitate sebum removal on the 87/13 polyester/spandex surface. On the other hand, adding low molecular weight primary amines (ethylene diamine, or monoethanolamine [MEA]) in the surfactant system without salt showed sebum removal of 70%–80% depending on the amine molecule. Adding MEA as a detergency additive with salt appeared to achieve good detergency (>80% removal) at all studied HLD numbers between −1.0 and 1.1 and the maximum detergency (approximately 90% removal) was observed at the optimum formulation (HLD = 0). The formulation pH with added MEA decreased from 11 to roughly 9. Detergency performance with added MEA was not dependent on pH within the studied basic conditions. The principal cold water sebum removal mechanism was found to be detachment of solid sebum fractions, dispersed in the detergent bath or floating on the bath surface.

Effect of Surfactant Systems, Alcohol Types, and Salinity on Cold‐Water Detergency of Triacylglycerol Semisolid Soil. Part II

AbstractOur prior work found that detergency of coconut oil was relatively poor using C14‐15‐8PO‐SO4Na alone but showed promising improvement with the presence of linear intermediate‐chain alcohols (C7–C9 alcohols) in the surfactant formulation. The maximum detergency exceeded 90% removal using 0.1 w/v% C14‐15‐8PO‐SO4Na/0.2 w/v% 1‐octanol/4 w/v% NaCl (final optimized surfactant system) at 10 °C. The current work thus seeks to further investigate surfactant formulations capable of providing improved detergency performance. Different 50% linear anionic extended surfactant structures (LC14‐15‐8PO‐SO4Na, LC14‐15‐8PO‐3EO‐SO4Na, and LC14‐15‐8PO‐7EO‐SO4Na) were compared with the branched C14‐15‐8PO‐SO4Na previously studied. Detergency of coconut oil using C14‐15‐8PO‐SO4Na at 8 w/v% NaCl (S*) still performed more effectively than these new surfactant systems. The addition of octanol as a detergency additive was further studied, and it showed that S* reduced from 8 w/v% NaCl to 4 w/v% NaCl for 1‐octanol and to 2 w/v% NaCl for 2‐octanol and 2‐ethyl‐hexanol in the C14‐15‐8PO‐SO4Na surfactant formulation. Coconut oil removal significantly improved detergency from roughly 49% for no alcohol with 8 w/v% NaCl, to 83% for 2‐ethyl‐hexanol with 2 w/v% NaCl, to 95% for 1‐octanol with 4 w/v% NaCl, and to 98% for 2‐octanol with 2 w/v% NaCl. Further studies on octanol concentration showed that decreasing 1‐octanol from 1.2% (90 mM) to 0.2% (15.3 mM) and 2‐octanol from 1.2% (90 mM) to 0.5% (38.5 mM) still maintained detergency over 90% removal. In this work, cold‐water detergency was found to correlate with low interfacial tension above the melting point, improved wetting of the semisolid soil, and oil solubilization in surfactant micelles.

Experimental Design for Optimizing the Cleaning of Starch Adhering to Stainless‐Steel Surfaces Using Nonionic Surfactants and Silica Microparticles

AbstractThe statistical design of experiments has been used to assess the detergency of starch adhering to stainless steel considering three factors: pH, flow rate, and concentration of silica particles in the cleaning solution. The cleaning tests were carried out in a continuous‐flow device that simulates the behavior of a Cleaning‐In‐Place washing system. Different statistical designs were used to evaluate the detergency of cleaning solutions in the absence of surfactants and with two nonionic surfactants, i.e., an ethoxylated alcohol, and an alkylpolyglucoside (APG). Expressions were developed to simulate detergency levels as a function of the variables assayed, determining the optimal detergency of each cleaning solution studied. The results indicate that the variable most influential on detergency was pH. Cleaning solutions with high alkalinity are required to achieve a significant cleaning efficiency. On the other hand, the silica‐particle concentration did not influence the detergency results using cleaning solutions without surfactants. Nevertheless, the addition of either the ethoxylated alcohol or the APG to the cleaning solution with silica particles has a significant effect on detergency: it diminished with the ethoxylated alcohol and increased with the APG. Maximum detergency was found at the highest level of pH, particle concentration, and flow rate when the APG was added to the cleaning solution.

Cold Water Detergency of Triacylglycerol Semisolid Soils: The Effect of Salinity, Alcohol Type, and Surfactant Systems

AbstractCold water detergency of triacylglycerol semisolid soils is much more challenging than liquid vegetable oils due to poorer interaction between surfactants and semisolid soil. This research seeks to improve the removal efficiency of semisolid soils below their melting points using surfactant‐based formulations containing different alcohol additives. To this end, cold water detergency of solid coconut oil and solid palm kernel oil was investigated in various surfactant/alcohol systems, including single anionic extended surfactants, single nonionic alcohol ethoxylate surfactants, and a mixture of anionic surfactants. A series of alcohols (2‐butanol, 1‐hexanol, 1‐heptanol, 1‐octanol, 1‐nonanol, and 1‐decanol) were added to the surfactant formulations to investigate cold water detergency improvement. While cold water detergency using surfactants alone was poor, it was considerably improved when optimum salinity (S*) and 1‐heptanol, 1‐octanol, or 1‐nonanol were introduced to the studied surfactant formulations. The maximum detergency of solid coconut oil exceeded 90% removal in the 0.1 w/v% C14‐15‐8PO‐SO4Na/0.2 w/v% 1‐octanol/4 w/v% NaCl system (a final optimized surfactant system) at a washing temperature of 10°C versus 22.9 ± 2.2% in the surfactant alone (not at optimum salinity and no additive). Further analysis showed that improved cold water detergency using surfactant/intermediate‐chain alcohols/NaCl could be correlated with high wettability (low contact angle) as well as favorable surfactant system‐soil interaction as observed by lower interfacial tension values. In contrast, the improved cold water detergency was observed to be independent of dispersion stability. This work thus demonstrates that surfactant system design, including additives, can improve cold water detergency of semisolid soils and should be further explored in future research.

Analysis of different protocols for the cleaning of corn starch adhering to stainless steel

Cleaning-in-place is a process used in food industries to maintain the hygiene in the process. This work analyses the effect that different cleaning protocols exert on the cleaning of starch adhering to stainless-steel surfaces. The objective is to optimize the cleaning process reducing its environmental impact by diminishing the consumption of reagents and the energy consumption. These protocols include different processes (ozonation, enzyme recovery), experimental conditions (pH, temperatures, time, recirculation flow, ozone gas concentration) and composition of the washing solutions (enzyme, surfactant, silica microparticles). In the absence of enzyme, the maximum detersive effectiveness (61.9%) was obtained using a protocol that includes ozone and fatty ethoxylated alcohol at 45 °C. In the presence of the enzyme, the maximum detergency (97.0 ± 4.7%) was obtained using the highest enzyme concentrations (1.00 g/L), 60 °C and 45 min. Finally, the viability of reusing the enzyme was confirmed after different washing cycles that incorporated intermediate centrifugation stages.

Correlation analysis between particulate soil removal and surface properties of laundry detergent solutions

The purpose of this study is to correlate surface properties of laundry detergents and model surfactant solutions with their washing abilities. For the study, laundry detergents available on the Polish market were selected and categorized according to their retail price: the cheapest ( P1, P2, P3), average priced ( P4, P5, P6, P7, P8) and the most expensive ( P9, P10). Anionic sodium dodecylbenzenesulfonate and nonionic nonaethylene glycol monodecyl ether were used for the preparation of the model solutions. The content of the anionic and nonionic surfactants in the detergents was determined. Cotton fabrics were soiled with black carbon/olive oil, make-up, curry, red wine, tomato sauce, blood, chocolate, peat, tea, β-carotene, grass, animal fat/red dye, baby food, clay, butter and used engine oil. Detergency tests were carried out at a temperature of 40℃ in laboratory conditions using washing powders and model surfactant solutions in various concentrations. On the basis of the correlation between detergency and detergent properties, the most favorable size range of powder granules was identified. The negative correlation between contact angle, surface tension and detergency and the positive relationship between phosphorus pentoxide and active oxygen content, spreading coefficient, diffusion coefficient and detergency were determined. The closest correlation between surfactant content and detergency was observed at a concentration of 10 g/L, which resulted in maximum detergency. When the emulsifying properties were better, their soil removal efficiency was greater. Based on the analysis of the correlation, the characteristics of the tested laundry detergent solutions that had the greatest ability to remove dirt were described.

Combination effect of ultrasound and shake as a mechanical action for textile cleaning

The ultrasonic cleaning of artificially soiled fabrics with and without shake was carried out in an aqueous anionic surfactant solution. The polyester, cotton and polyester/cotton (65/35) fabrics were soiled with oleic acid or carbon black as a model soil, and cleaned together with their original fabrics with applying ultrasound for 5min. The detergency and the soil redeposition were determined from the change in the Kubelka–Munk function of the soiled and original fabric surfaces due to the cleaning. For any fabric, the removal of oleic acid and carbon black from the soiled fabric and their redeposition onto the original fabric increased with increasing electric power consumption of ultrasound. When ultrasound and shake were applied at the same time, the detergency further increased for any electric power consumption. The maximum detergency obtained with combination of ultrasound 340W and shake 160spm was compared with detergency obtained with Wascator, a horizontal axis drum type washer. It was found that the ultrasound/shake combination cleaning enabled efficient removal of both soils from any fabric and the detergency of the polyester fabrics was comparable to that with Wascator. The mechanical action during the washing was evaluated by two mechanical action test pieces commercially available, which indicated that the ultrasound/shake combination cleaning provided gentle mechanical action to the fabric in comparison with the drum type washer. The SEM observations showed the damage of the fabric and fiber surfaces was negligibly small after the ultrasound/shake combination washing.

Microemulsion‐Based Vegetable Oil Detergency Using an Extended Surfactant

AbstractThis work examined the use of a single extended surfactant in the microemulsion‐based detergency of vegetable oils. The results showed that good canola oil detergency (>80%) was achieved at 25 °C using a single extended surfactant (C14,15–8PO–SO4Na) at concentrations as low as 125 ppm, i.e., significantly lower than the surfactant concentration range of 500–2,500 ppm reported in other microemulsion‐based detergency work. It was found that the maximum detergency (95%) was achieved in the type II microemulsion region. These results demonstrate that the microemulsion‐based extended surfactant formulation is a promising approach for vegetable oil detergency at low temperature.

Enhanced triolein removal using microemulsions formulated with mixed surfactants

AbstractIn previous work, a microemulsion‐based formulation approach yielded excellent laundry detergency with hydrophobic oily soils hexadecane and motor oil. In this work, the same approach is used in detergency of triolein, which is a model triglyceride, some of the most difficult oils to be removed from fabric. The linker concept was applied in formulation of the microemulsion system. Three different surfactants were used: (i) dihexyl sulfosuccinate, an ionic surfactant with a moderate hydrophile‐lipophile balance (HLB); (ii) secondary alcohol ethoxylate, a lipophilic nonionic surfactant with a very low HLB; and (iii) alkyl diphenyl oxide disulfonate (ADPODS), a hydrophilic anionic surfactant with a very high HLB. The phase behavior and interfacial tension (IFT) of the surfactant systems were determined with different concentrations of ADPODS. The results indicate that as the HLB of the system increases, a higher salinity is required to shift the phase transition from Winsor Type I to Type III to Type II. The three formulations at different salinities were used in detergency experiments to remove triolein from polyester/cotton sample fabric. The results showed that there were two peaks of maximum detergency in the range of salinity from 0.1% to 10% NaCl. The higher the hydrophilicity of the system, the higher the salinity required for maximum detergency. The results of the dynamic IFT and the detergency performance from two rinsing methods lead to the hypothesis that one of these maxima in detergency results from a spreading or wetting effect. The other maximum in detergency is believed to be related to ultralow IFT associated with oil/water middle‐phase microemulsion formation. Triolein removal exceeding 80% was attained, validating the microemulsion approach to detergency.

Microemulsion formation and detergency with oily soils: III. Performance and mechanisms

AbstractThe objective of this study was to investigate the correlation between oily soil removal efficiency and low oil‐water interfacial tension (IFT) generated by microemulsion formation. A mixture of sodium dioctyl sulfosuccinate, alkyl diphenyl oxide disulfonate, and sorbitan monooleate was selected as a detergent formulation to evaluate detergency performance for two highly hydrophobic oils: hexadecane and motor oil. The maximum detergency corresponds to formation of a Winsor Type III microemulsion as well as to the supersolubilization region, which is a Winsor Type I microemulsion close to the Winsor Type III region. In addition, the oil removal in the rinse step is almost as high as that in the wash step for both regions. We propose the following mechanism to explain these results: During the wash step, the contact angle of the oil on the fabric surface is progressively increased, resulting in the detachment of the oil droplets. However, owing to the very low IFT, the spreading effect is dominant, thereby causing incomplete oil removal. During the subsequent rinse step, the IFT increases, passing through a composition at which the rollup mechanism causes additional oil removal. These results demonstrate that microemulsion formation and the resulting IFT reduction are important mechanisms in oily soil detergency.

Modell zur Ermittlung der Waschkraft einiger technischer nichtionischer Tenside / Modelling of detergency performance for some technical nonionic surfactants

The detergency behaviour towards nonpolar soil was modelled for seven technical nonionic surfactant as a function of surfactant concentration, washing time and washing temperature. The detergency experiments were carried out according to a central composite circumscribed statistical experimental design. Second order polynomial functions were used for the modelling. It was possible to establish good models for all surfactants except one. For three of the surfactants the models predicted a detergency maximum. The detergency effects of these surfactants were examined at the variable settings predicted to give maximum detergency. The results obtained were in good agreement with predictions. The surfactant concentration giving maximum detergency is not directly linked to the c. m. c. The temperature for maximum detergency corresponds to the cloud point of the washing solution with the surfactant concentration giving maximum detergency. The cloud point has to be determined with the soil present. This indicates that a microemulsion has to be present to obtain maximum nonpolar soil removal.

Influence of calcium concentration in the washing liquor on detergency performance of linear alkylbenzene sulfonate

The effect of the concentration of linear alkylbenzene sulfonate (LAS) on soil removal efficiency at various water hardnesses was studied. The present investigation indicates that: (i) For each LAS concentration, a calcium ion concentration interval exists, defined by 0.78<(Log(LAS)/Log(Ca))<0.85, where the detergency reaches a maximum; (ii) 24 h after having been prepared, the solutions present either clear solutions (water appearance), milky solutions (without precipitate in the bottom of the bottle), or clear solutions with precipitate in the bottom of the bottle. The milky solutions correspond to the defined interval. The solutions where the relationship LAS/Ca is defined are located, surprisingly in a precise zone of the LAS‐calcium solubility diagram. The study has been carried out with and without ionic strength buffering, and the addition of electrolyte moves the maximum detergency performance interval to higher calcium concentrations.

Soap‐based detergent formulations: XIII. Formulations with alpha‐olefin sulfonates as lime soap dispersants

AbstractHeavy duty household type detergents were formulated from tallow soap‐AOS(α‐olefin sulfonate)‐builder combinations. Various commercial AOS samples were evaluated. These were derived either from closely fractionated α‐olefins such as C14, C16, and C18 or from samples representing broader mol wt ranges such as C14−C16 and C16−C18. The builders incorporated into these combinations were a sodium silicate (Na2O∶SiO2=1∶1.6), sodium tripolyphosphate, sodium citrate, sodium carbonate, and trisodium nitrilotriacetate. Detergency evaluations of 0.2% solutions in 300 ppm hard water (as CaCO3) were determined with three commercial soiled cloths and by a multiwash test in which clean cloth was repeatedly soiled and washed. The relative proportions of soap, AOS, and builder were varied to obtain maximum detergency, and comparisons were made to other soap‐LSDA (lime soap dispersing agents)‐builder combinations as well as to a commercial high phosphate detergent used as a control. Detergency performance of soap‐AOS combinations ranked just below that of the commercial high phosphate detergent control and below that of soap formulations containing sodium methyl α‐sulfotallowate.

Nonbuilt heavy duty liquids: Detergency and formulating parameters

AbstractThe detergency of nonbuilt heavy duty liquids containing linear alkylate sulfonate and/or linear alcohol ethoxylate nonionic active is discussed. Single cycle detergency on a broad range of linear alkylate sulfonate‐nonionic compositions was evaluated on cloths soiled in the laboratory with a mixture of synthetic sebum and dust and a commercially available soiled cloth, ACH #120A. The effects of multiple cycle wash testing also were covered. Formulating parameters to produce usable nonbuilt heavy duty liquids are discussed. The nonionic of choice for maximum detergency in nonbuilt heavy duty liquids should be derived from ca. a 14 carbon chain length alcohol with ca. 70% ethylene oxide. For optimum solubility, linear alkylate sulfonate should be the sodium salt derived from a linear alkylbenzene of ca. 235–240 mol wt, a product like that currently used in light duty liquids. The presence of linear alkylate sulfonate in nonbuilt heavy duty liquids helped reduce product clear point. Nonionics were found to give the best performance on cotton cloth. Linear alkylate sulfonates were most effective on synthetics. Multiple cycle testing with Spangler soil on nonbuilt heavy duty liquids was shown to be unnecessary. Mixed active systems gave the best overall product on the basis of performance and physical properties.

Studies of Detergency. XIII.

The soil removal efficiencies have been studied from the view of hydrophilic or oleophilic nature of surfactants, soil, and fabrics.In the case of washing by the detergent that is mainly formulated with LAS, the detergency depends on water hardness. The water hardness dependencies on the detergency for the hydrophilic fabrics such as cotton and nylon are comparatively small, but are great for the oleophilic fabrics such as wool, and consequently the maximum detergency is observed at a some water hardness.The water hardnesses corresponding to the maximum detergency depend on the polarity of soils adhered on fabric and increase with the increase of the polarity of soil.In the case of washing by the detergents that are mainly formulated with non-ionic surfactants, the dependency of detergency on the HLB of the surfactants is little for the hydrophilic fabrics such as cotton, but is great for the oleophilic fabrics such as wool.

Experiments in the formulation of heavy duty liquid detergents from tallow

AbstractSeveral tallow‐based detergents were investigated in simplified formulations comprising ca. 10~15% active ingredient, 4% foam stabilizer, 10% isopropyl alcohol, 20% K4P2O7 and 50~55% water, 1% with respect to carboxymethylcellulose. Disodium 2‐sulfoethyl ॅ‐sulfostearate or sodium oleate could be used as the only active ingredient or in blends with other tallow‐based compounds. The presence of a soluble form of the tallow alcohol sulfates, sodium 9,10‐dichlorooctadecyl sulfate, gave maximum detergency in hard water.

Studies on the Detergency of Nonionic Surfactant. V.

Relation between detergency and length of ethylene oxide chain was investigated with nonionic surfactants in this paper.With the artificially soiled woolen cloth the length of ethylene oxide indicating maximum detergency was found to become longer as the washing temperature rises higher.Furthermore, it was reconfirmed with the natural soils that the optimum length changes to a large extent, depending upon the kind of soils.

Studies on the Detergency of Nonionic Surfactant. III

In this paper, polyoxyethylene nonylphenyl ether EO 10 mol (PEG-N10) and dodecyl benzene sulfonate (Na-DBS) were investigated on the relationship of detergency and quantity of surface active agent absorbed by fabric.It was found that there was a close relationship between quantity of surface active agent absorbed and whiteness retention with wool, and the reason why PEG-N10 is somewhat inferior to Na-DBS in maximum detergency is justifiable because of its lower whitenness retention.

Hard surface detergency

In a study of hard surface detergency using glyceryl trioleate, oleic acid, and octanoic acid soils with three types of anionic and three types of nonionic syndets, only potassium laurate showed maximum detergency at the CMC (critical micelle concentration), with the potassium laurateoctanoic acid system being an exception. In general glyceryl trioleate and oleic soil removal (180°F.) at the CMC was low, not over 40%; octanoic acid detergency at the CMC was substantially higher, 65 to 83%. Considerable differences in removal of the various soils by the same surfactants were found. A generalization was observed in the detergency of glyceryl trioleate soil—soil removal increased sharply on passing the CMC with increasing concentration until approximately 90% detergency was reached, at which point soil removal began to level off and approach 100% with a much smaller slope. Visual observations of the cleaning processes suggested a partial answer for the differences in soil removal. Removal or glyceryl trioleate soil by both anionic and nonionic syndets appeared to be due chiefly to a displacement action caused by preferential wetting of the basis metal. Removal of octanoic acid by the nonionic surfactants in a diffusing cloud of small particles seemed to be due to solubilization followed by emulsification and precipitation of the acid soil. Several relationships were discovered in two series of analogs (polyethenoxyethers of nonyl phenol and tridecyl alcohol). It was found that the ratio of the HLB (hydrophile-lipophile balance) values of two analogs was approximately equal to the fifth root of the ratio of their CMC values. The correlation held for analogs varying by as much as 15 moles ethylene oxide. A linear relationship was also found between HLB value and the reciprocal of the ethylene oxide mole ratio for the polyethenoxyethers of nonyl phenol.

Correlation between critical micelle concentration, fatty soil removal, and solubilization

Using two model soil-detergent systems (hard substrate/triglyceride; cotton/fat, mineral oil, graphite) it was shown that soil removal begins at, or near, critical micelle concentration (eme), confirming the work of other investigators with different systems. Maximum detergency occurs at concentrations considerably in excess of cmc, varying some 6 to 10 times cmc for different surfactants. An equation for soil removal showed excellent fit of experimental values for both detergency systems. Direct correlation between cmc, solubilization (of several materials), and soil removal was demonstrated. Marked differences between surfactant type and solubilization of triglycerides were found. The nonionic surfactants were excellent solubilizers for triolein correlating with their effective soil removal. Neither sodium oleate nor sodium tripolyphosphate effectively solubilized the triglyceride but both are effective soil removers, suggesting that their soil removal mechanism differs from the nonionics, possibly as an emulsification or displacement mechanism. Solubilization of triglyceride occurs most effectively considerably in excess of cmc.