Polyglycerol modified polysiloxane surfactants: Their adsorption and aggregation behavior in aqueous solution

Guoyong Wang,Yanyan Zhu,Yunhui Zhai,Wanxu Wang,Zhiping Du,Jieqiong Qin 한국공업화학회 2017 Journal of Industrial and Engineering Chemistry Vol.47 No.-

A simple process to synthesize polyglycerol modified polysiloxane surfactants has been carried outapplying a “grafting-to” approach. After formation of allyl polyglycerol ether (APGE) from diglycerol(DGY) and allyl glycidyl ether (AGE), polysiloxane modified by designed number of polyglycerol groups(PHMS-APGE) were obtained by connecting the APGE structure to different Si H functionalizedpolyhydromethyl siloxane (PHMS). The synthesized APGE-PHMS were characterized by IR and 1H NMR. Solubility measurements showed that the solubility of the as-prepared polymers increased in polarsolvents with the increasing of the amount of hydrophilic APGE groups. Furthermore, the surface activity,surface adsorption, aggregation and spreading behaviors of APGE-PHMS were investigated utilizingsurface tension measurements, dynamic light scattering (DLS), transmission electron microscopy (TEM)and contact angle measurements. The results showed that critical aggregation concentration (CAC) andthe time needed to reach adsorption equilibrium on water surface decrease systematically with theincrease in the number of APGE groups. These polymers in aqueous solutions could aggregate to formspherical assemblies. Moreover, the spreading behavior of these polymers on low energy surface wasfound to be influenced by the number of hydrophilic APGE groups.

Surface and foam property of perfluoroalkyl polyoxyethylene ether phosphate salt in aqueous-ethanol system

Bo Ning,Yan Wang,Mi Zhang,Yanyun Bai,Xiumei Tai,Wanxu Wang,Guoyong Wang 한국공업화학회 2021 Journal of Industrial and Engineering Chemistry Vol.94 No.-

Foam is used in manyfields with excellent performance. Moreover, disinfectants with ethanol as themain ingredient have increasingly been used in people's lives. However, the foam research of an ethanolwatermixed system is still in the initial stage. In this work, a perfluoroalkyl polyoxyethylene etherphosphate salt surfactant (FEP-Na) was synthesized through a new molecular design. The surfactant hasgood interfacial adsorption behavior in 50% ethanol-water mixing system, and the approximatelyspherical aggregates are observed in the volume phase of the solution. Moreover, FEP-Na showed goodfoaming property in 50% ethanol-water mixed solution. Interestingly, high concentration solutions withhigh surface activity have lower foam stability. And under the microscope, we see that the bubble burst isdominated by the phenomenon of coalescence. In this regard, we explain the mechanism of foamstability by electrostatic double layer theory and interfacial dilation rheology. It provides a new choice forthe synthesis of foaming agent in the ethanol-water mixed system at a concentration of 50%.

Investigation on Strain Characteristics and Fatigue Constitutive Model of Limestone under Osmotic Pressure and Cyclic Disturbance Coupling

Zhanping Song,Wanxue Song,Yun Cheng,Tengtian Yang,Tong Wang,Kuisheng Wang 대한토목학회 2022 KSCE JOURNAL OF CIVIL ENGINEERING Vol.26 No.4

The existing fatigue models are not sensitive to load cycles and do not consider the effect of osmotic pressure. To study the strain characteristics and fatigue constitutive model of limestone under osmotic pressure and cyclic disturbance coupling, 300 cycles of loading and unloading tests under different osmotic pressures were carried out and the evolution characteristics of irreversible accumulative deformation curve were analyzed. Then, an improved Nishihara fatigue model was established based on the theoretical results of rheological model by introducing the nonlinear function into Nishihara model. The results show that the irreversible cumulative deformation under different osmotic pressures experiences three evolutionary processes of initial deformation stage, stable deformation stage, and accelerated deformation stage with increasing cycle indexes, showing the typical fatigue deformation characteristics. The axial deformation at initial deformation stage increases significantly, the stable deformation stage shows approximately linear growth and accounts for 40% to 73% of total cycle indexes, and the accelerated deformation stage shows a sudden increase indicating the overall instability of limestone. The nonlinear function is introduced into the Nishihara fatigue model based on rheological theory, and a fatigue deformation model that can reflect the entire process of irreversible accumulative deformation curve is established. The physical meanings of model parameters are discussed, and the relationships between model parameters and cycle indexes are inverted. The model parameters have good convergence and verify the rationality and applicability of the fatigue constitutive model based on experimental data. The results have reference value for revealing the fatigue characteristics of rock under osmotic-cyclic stress coupling.

Micellization and aggregation properties of sodium perfluoropolyether carboxylate in aqueous solution

Qiwen Yin,Wanxu Wang,Wei Xue,Yanyun Bai,Xiaoyuan Ma,Zhiping Du,Guoyong Wang 한국공업화학회 2016 Journal of Industrial and Engineering Chemistry Vol.42 No.-

Sodium perfluoropolyether carboxylate (PFPE-Na) was synthesized via hydrolyzing the correspondinghexafluoropropylene oxide oligomer (PFPF). The structure of PFPE-Na was characterized by FT-IR and 19FNMR. The micellization and aggregation properties of PFPE-Na surfactant in aqueous solution werestudied systematically using equilibrium surface tension, electrical conductivity, dynamic surfacetension, steady-statefluorescence, transmission electron microscopy (TEM) and contact anglemethodologies. The results of equilibrium surface tension at 25 C showed that the critical micelleconcentration (CMC) and the surface tension at CMC (gCMC) of PFPE-Na aqueous solution are lower thansodium perfluorooctanoate [NaPFO, C7F15COONa], which revealing that as a kind of environment-friendly surfactant, PFPE-Na is a perfect substitute of NaPFO. Electrical conductivity measurementsimplied that the micellization of PFPE-Na in aqueous solution was an exothermic and entropy-drivenprocess in the range of temperature investigated. Steady-statefluorescence and transmission electronmicroscopy (TEM) may indicate that PFPE-Na self-assemble in aqueous solution to form larger sphericalaggregates with the increase of concentration. In addition, dynamic surface tension measurements ofPFPE-Na solution showed an extremely efficient adsorption at concentrations above CMC while thedetermination of contact angle of PFPE-Na showed the wetting ability was general.

Adsorption, aggregation and wetting behaviors of biodegradable surfactant: Perfluoropolyether quaternary ammonium salt

Jixian Shen,Yanyun Bai,Qiwen Yin,Wanxu Wang,Xiaoyuan Ma,Guoyong Wang 한국공업화학회 2017 Journal of Industrial and Engineering Chemistry Vol.56 No.-

A novel cationicfluorinated surfactant, (PFP-AI), was synthesized via amidation and quaterisationsuccessively with perfluorinated acylfluride (PFPF) as starting material. Their structure was analyzed byFT-IR, 1H NMR and 19F NMR. The TG indicated the PFP-AI possess thermal stability with initiationdecomposition temperatures about 217 C. The physicochemical properties of PFP-AI were studiedsystematically by equilibrium surface tension, dynamic surface tension, dynamic light scattingmeasurement (DLS) and transmission electron microscopy (TEM). The results revealed the PFP-AIexhibited high surface activity (gcmc = 16.4 mN/m) and could aggregate into vesicles at the concentrationof 4.15 mmol/L. Furthermore, contact angle measurements demonstrated that PFP-AI exhibited efficientwettability on the hydrophobic surface.

Novel coal and siloxane based surfactants: Bola polysiloxanes modified with butynediol-ethoxylate and their properties

Pengxiao Fang,Yanyun Bai,Xiaoyuan Ma,Xiumei Tai,Wanxu Wang,Guoyong Wang 한국공업화학회 2018 Journal of Industrial and Engineering Chemistry Vol.59 No.-

Novel polysiloxane amphiphiles obtained by introducing coal-based amphiphiles (butynediol ethoxylate) into polysiloxanes based on hydrosilylation reaction by two steps: first, synthesizing hydride terminated polysiloxane with different degree of polymerization (HTP); second, butynediol-ethoxylate was grafted on hydride terminated polysiloxane at terminals to get bola coal-based polysiloxane amphiphiles (EO-PSi-EO). In our work, EO-PSi-EO were compared together to investigate the impacts of different ratios of hydrophilic and hydrophobic groups on its properties. A conclusion was obtained from the work that EO-PSi-EO with various hydrophobic backbones have low surface tension, rich aggregate behavior, excellent wetting property and low foam.