Su, Hong; Chai, Jing; Li, Xiang; Kong, Yangzhi; Zhang, Yanling; Kang, Jing; Dong, Alideertu
doi: 10.1002/jsde.12768pmid: N/A
The quality and safety of dairy products are highly valued by consumers and dairy manufacturers, which is mainly ensured by thorough cleaning of dairy production equipment. Milk fouling can cause pipes to clog and reduce transmission. Incomplete cleaning can cause microbial breeding, which will affect the quality and safety of dairy products. To achieve efficient and rapid cleaning of dairy processing equipment, cleaning agents have always been a necessary choice for dairy and food enterprises. This paper describes the production mechanism of milk fouling, the cleaning mechanism by cleaning agents, and the cleaning process. Development of cleaning agents are introduced in detail, include compound alkaline/acid/neutral cleaning agents, enzyme cleaning agents and cleaning additives. The factors affecting cleaning efficiency are also viewed, which include type and dosage of cleaning agents, cleaning process (cleaning time, cleaning liquid temperature, cleaning fluid flow rate), and other influencing factors (cleaning fluid pressure, Reynolds number and shear stress, surface types). Four aspects are reviewed in this manuscript, include cleaning objects (milk fouling), cleaning substances (cleaning agents), how to clean (cleaning mechanism) and how to clean efficiently (cleaning influencing factors), which provides a valuable reference for the improvement of the dairy cleaning process.
Yaagoob, Ibrahim Y.; Goni, Lipiar K. M. O.; Mazumder, Mohammad A. J.; Verma, Chandrabhan; Ali, Shaikh A.; Alfantazi, Akram
doi: 10.1002/jsde.12737pmid: N/A
In the current study, a tetracationic quaternary ammonium salt (TCQAC) was synthesized and characterized and its ability to suppress corrosion on mild steel (MS) in a 0.5 M H2SO4 solution was examined. Various chemical, electrochemical, and surface characterization techniques were utilized to study the inhibition efficiency of TCQAC. The TCQAC manifests 99.83% efficiency at 20 ppm concentration. Out of all the examined isotherm models, the Langmuir isotherm offered the best fit for the TCQAC adsorption on the MS surface. A very high negative value of ΔGads (−45.18 kJ mol−1) suggests that the adsorption of TCQAC followed the chemisorption mechanism. Electrochemical studies indicate that TCQAC increases the linear and charge transfer resistances (LPR and Rct, respectively). TCQAC slows down the anodic and cathodic Tafel reactions; however, it acts as an anodic‐type inhibitor at 5, 10, and 20 ppm. The appearance of extra Cl and N signals in the energy dispersive x‐ray (EDX) spectrum and an improvement in surface smoothness in the scanning electron microscope (SEM) image of the inhibited sample corroborated the adsorption method of corrosion inhibition. X‐ray photoelectron spectroscopy (XPS) study indicates that TCQAC creates corrosion preventive layers by chemical adsorption. In Frontier molecular orbitals (FMOs), highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) were delocalized around the central part that comprises two benzyls, four allyls, and one hydrocarbon ((CH2)6) moieties and two quaternary nitrogen atoms. The outcomes of XPS and density functional theory (DFT) analyses indicate that the chemisorption of TCQAC occurs by dπ–pπ bonding with the surface iron atoms. The π‐electrons of aryl and allyl moieties extensively participate in the bonding.
Paranjpe, Susmita Suhas; Sanap, Prasad Sanjaykumar; Madankar, Chandu; Pratap, Amit Prabhakar
doi: 10.1002/jsde.12740pmid: N/A
Gemini surfactants are dimeric molecules having two monomeric units connected by a spacer. Gemini surfactants, owing to their molecular structure have better surfactant properties than other monomeric surfactants. Esterquat class gemini surfactants can be synthesized using a spacer containing ester linkages. In the current study, the synthesis of novel esterquat gemini surfactants was carried out with spacers of varying chain lengths and was characterized using sophisticated instrumental methods. Various surfactant properties including foaming, emulsification, CMC, surface excess, antimicrobial activity and wetting potential using contact angle were analyzed and compared with benzalkonium chloride. It was observed that the CMC as low as 24.79 × 10−3 mM of the synthesized surfactants is potentially lower than that of conventional monomeric surfactants and was found to increase with an increase in spacer chain length. Further, the applicability and evaluation of performance properties of the synthesized surfactants were studied in fabric softener formulation. The water absorbency and whiteness retention of the formulation prepared using 12‐6‐12 GS was the highest due to its better wettability amongst other synthesized surfactants owing to its higher spacer chain length. To summarize, the surface and anti‐microbial properties of the synthesized surfactants vary greatly with the alteration in spacer chain length.
Li, Wanchun; Shen, Jie; Xu, Hujun
doi: 10.1002/jsde.12753pmid: N/A
Green surfactants produced from peptides and their derivatives have excellent surface chemistry and application properties. A mild, biocompatible, and rapidly biodegradable green surfactant, potassium N‐lauroyl wheat peptide (PLW), was synthesized by an acylation method in the aqueous phase with lauryl chloride and wheat oligopeptide as starting materials. Furthermore, the isoelectric point, equilibrium surface tension, dynamic surface tension, micellar aggregation behavior, foaming, and irritating properties of PLW were studied. Wheat oligopeptides were discovered to have the greatest glutamic acid content, accounting for 30.92% of the overall amino acid composition. The findings revealed that the protonation and ionization behavior of PLW was pH dependent. At pH 8.5, water's surface tension was lowered to 32.1 mN/m−1. At high concentrations and pH, PLW formed large aggregates in solution, causing the adsorption behavior of PLW molecules to shift from diffusion‐controlled adsorption to mixed kinetic adsorption, with PLW exhibiting great surface activity. Furthermore, PLW has good foaming properties and is non‐irritating. As a result, PLW is predicted to become widely employed in the field of household chemicals.
Kumar, Vinod; Padsala, Shailesh; Mayursing, Girase; Ray, Debes; Aswal, Vinod Kumar; Kuperkar, Ketan; Bahadur, Pratap
doi: 10.1002/jsde.12743pmid: N/A
The micellization behavior of conventional cationic surfactant: tetradecyltrimethylammonium bromide (TTAB), and Gemini surfactant (GS): N,N′‐ditetradecyl‐N,N,N′,N′‐tetramethyl‐N,N′‐ethanediyl‐diammonium dibromide (14‐2‐14) in water and water‐trifluoroethanol (TFE) solvent mixture has been examined using tensiometric and small‐angle neutron scattering (SANS) techniques. Critical micelle concentration (CMC), and various interfacial parameters such as surface tension at CMC (γCMC), surface pressure at CMC (πCMC), maximum surface excess concentration (Γmax), and minimum area occupied by the head group (Amin) were evaluated for our examined systems at 303.15 K. It was observed that with the increase in TFE concentration, the CMC of the tested cationic surfactants decreased, thereby favoring the micellization in the presence of the surface‐active TFE. Furthermore, the geometry and aggregation number (Nagg) of surfactant micelles were inferred using SANS that revealed the decrease in micelle size of cationic surfactants. Additionally, the computational simulation study provided an insight into the molecular interactions in the examined system that validated our experimental findings.
Wu, Tianquan; Liu, Hailong; Tan, Jinglin
doi: 10.1002/jsde.12744pmid: N/A
A series of carboxylated carbosilane surfactants with methyl, ethyl, branching CH3, phenyl, and cyclohexyl (Me‐Si2C‐COONa, Et‐Si2C‐COONa, Si2C‐La‐COONa, Ph‐Si2C‐COONa, and Cy‐Si2C‐COONa) were prepared. The effect of isomer and steric hindrance on their micellization in aqueous solution was investigated by surface tension, conductivity, transmission electron microscopy (TEM) and dynamic light scattering (DLS). Si2C‐La‐COONa with branching CH3 shows a lower γCMC value and higher the CMC value compared with Et‐Si2C‐COONa. Cy‐Si2C‐COONa with cyclohexyl (41.6 mN m−1) and Ph‐Si2C‐COONa with phenyl (43.9 mN m−1) have larger γCMC values due to the distinct steric hindrance and hydrophobicity. In aqueous solution, the aggregation behavior of Si2C‐La‐COONa, Cy‐Si2C‐COONa, and Ph‐Si2C‐COONa is enthalpy‐driven. However, the micellization process of Me‐Si2C‐COONa and Et‐Si2C‐COONa is governed by the enthalpy‐driven at high temperature and entropy‐driven at low temperature. DLS and TEM results indicate that the carboxylated carbosilane surfactants can self‐assemble into aggregate with hydrodynamic diameters of 50–400 nm.
Sarıkaya Yıldız, İkbal; Bilgen, Selçuk; Akbaş, Halide
doi: 10.1002/jsde.12755pmid: N/A
The micellization properties of mixed aqueous solutions of a cationic gemini surfactant (CGS) and Triton X‐100, a conventional non‐ionic surfactant, with various mole fractions, were determined by measuring the surface tension at different temperatures. Various theoretical models were used to analyze the behavior of this mixed system. The interactions between CGS and Triton X‐100 were determined to be non‐ideal and synergistic. The calculated interaction parameters (βM) have negative values at all temperatures and for all mole fractions, showing attractive interactions. It was found that increasing the mole fraction of Triton X‐100 significantly increased the synergistic effect (more negative values). Micellar aggregation number (Nagg) values of pure surfactants and their mixtures in different ratios were obtained with the steady‐state fluorescence quenching method. Furthermore, the molar solubilization ratio of Sudan III organic dye in all surfactants aqueous systems was obtained using UV–Visible spectrophotometry. At concentrations above critical micelle concentration, the solubility of Sudan III in water was substantially increased linearly for all systems and it was observed that the enhancement was even more significant for mixed surfactant systems.
Wang, Yuling; Guo, Jixiang; Zan, Min; Xu, Songtang; Guo, Xueping; Du, Bo; Xu, Hujun
doi: 10.1002/jsde.12760pmid: N/A
The mixed system of sodium cocoyl glycinate and sodium hyaluronate (HA) with different mass concentrations and relative molecular weights was investigated by the surface tension method. All the curves of surface tension versus logarithm of concentration (γ‐lgc curves) of sodium cocoyl glycinate‐HA mixed system displayed the properties of double platform. The critical micelle concentration (cmc) of sodium cocoyl glycinate was 1.690 g/L at 25°C. The two inflection points of the γ‐lgc curves corresponding to the cocoyl glycine‐HA mixed system were cac (the critical aggregation concentration) and cmce (the extended cmc of sodium cocoyl glycinate), and cac < cmce < cmc. With the change of the mass concentration and relative molecular weight of HA, the cac values were almost constant. However, cmce increased with the increase of the mass concentration of HA at the same HA molecular weight. For the HA of molecular weight of 800 and 260000 Da, the mass concentration of HA increased from 0.05 to 0.4 g/L, and the cmce value increased from 1.199 to 1.390 g/L and 1.102 to 1.330 g/L, respectively. When the mass concentration of HA remained the same, the change in the relative molecular weight of HA had little effect on the cmce value. For the mixed system of sodium cocoyl glycine −0.1 g/L HA, when the concentration of NaCl was 2 g/L, the salt enhancement effect was dominant. When the concentration of NaCl was 4 to 8 g/L, the salt weakening effect was dominant. It is indicated that HA can improve the chemical properties of sodium cocoyl glycinate at a certain concentration, thus improving the cleaning, foaming, and foam stability of sodium cocoyl glycinate.
Shayanmehr, Mohammadesmaiel; Eslami, Fatemeh
doi: 10.1002/jsde.12745pmid: N/A
Storing thermal energy and using renewable energy are some of the most important challenges humanity faces today. Using phase change materials (PCM) is a suitable solution to prevent heat loss. PCM emulsions (PCMEs) have several advantages and are specifically applied in heat exchangers. Here, the formulation of these emulsions, the type of surfactants, and their composition based on freeze–thaw cycle stability are investigated. The Hydrophilic–Lipophilic‐Deviation (HLD) platform is used for this purpose. Considering the importance of stability during temperature changes in PCMEs, three types of surfactants that have different behaviors with respect to temperature are used: ethoxylates, ionics, and sugar‐based surfactants. By performing freeze–thaw cycles on emulsions made by individual surfactants, after 10 freeze–thaw cycles it was observed that the oil separation in each of the samples containing polysorbate80, AOT, lauryl‐myristyl‐alcohol‐polyethylene‐glycol‐ether, SDS, sorbitan‐monooleate, and decylglucoside occurred at the 2nd, 4th, 6th, 7th, 8th, and 10th‐cycle, respectively. Therefore, the sorbitan‐monooleate and decylglucoside had better freeze–thaw cycle stability compared to the others because of their non‐sensitivity to temperature. We also applied the emulsion cycle stability with two combinations of surfactants: (1) polysorbate80 and sorbitan‐monooleate, (2) decylglucoside and sorbitan‐monooleate. The former, despite the effect of temperature, showed no oil phase separation in the nine freeze–thaw cycles, but in the latter, the oil phase separation occurred in the 5th‐cycle. This study shows that synergism of surfactants is the most important factor in the stability of emulsions. To better explore these emulsion systems, the storage stability, freeze–thaw stability, droplet morphology, and viscosity tests were performed on different samples at various HLD values.
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