scholarly journals Preparation of alkali-resistant PVDF membranes via immobilization of sodium lauryl sulfate (SDS) on surface

2021 ◽  
Vol 11 (3) ◽  
Author(s):  
Gongpu Wen ◽  
Kun Chen ◽  
Yanhong Zhang ◽  
Yue Zhou ◽  
Jun Pan ◽  
...  

AbstractA novel strategy was proposed to fabricate alkali-resistant PVDF membrane via sodium lauryl sulfate (SDS) attached to the surface of membrane and immobilized by UV-curable polyester acrylate and tri(propylene glycol) diacrylate (TPGDA). The attached anionic surfactant, SDS, on the membrane surface can resist the alkali corrosion by NaOH, and the curing of the resin can immobilize the SDS on the membrane firmly. Due to the unique alkali resistance of SDS and resin formed, the UV-curable resin-modified PVDF membrane showed greatly enhanced alkali-resistant ability. Characterization of SEM and FTIR showed that polyester acrylate and TPGDA were cured successfully under the action of 1-hydroxycyclohexyl phenyl ketone (184) and ultraviolet light. Whiteness, differential scanning calorimeter and X-ray photoelectron spectrometer characterization showed that the modified PVDF membrane had a lower degree of dehydrofluorination than the pristine PVDF membrane after alkali treatment. Results of the detailed alkali-resistant analysis indicated that the F/C ratio of the UV-curable resin-modified PVDF membrane decreased by 2.6% after alkali treatment compared to pristine PVDF membrane decreased by 19.28%. The alkali-resistant performance was mainly attributed to the immobilized SDS. This study provided a facile and scalable method for designing alkali-resistant PVDF membrane, which shows a promising potential in the treatment of alkaline wastewater and alkaline-cleaning PVDF membrane.

Author(s):  
M. V. Bidevkina ◽  
M. I. Golubeva ◽  
A. V. Limantsev ◽  
I. N. Razumnaya ◽  
T. N. Potapova ◽  
...  

Sodium lauryl sulfate is the most common surfactant used in the production of detergents, chloroprene rubber, plastics, artificial furs and in pharmaceutical industry. Sodium lauryl sulfate is a moderately hazardous substance when introduced into the stomach (DL50 for white mice and rats is in the range of 2086-2700 mg/kg), has a pronounced local irritant effect on the skin and mucous membranes of the eyes, has a skin-resorptive, sensitizing and pronounced cumulative effects. The threshold for acute inhalation action is set at 15,3 mg/m3 for changes in the function of the nervous system and irritating effects on the mucous membranes of the upper respiratory tract (an increase in the total number of cells in the nasal flushes).Recommended for approval tentative safe exposure level of sodium lauryl sulfate in the air of the working area is 0.2+ mg/m3 (aerosol).


Polymers ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 405
Author(s):  
Demei Lee ◽  
Ya-Ling Tang ◽  
Shih-Jung Liu

We report the fabrication of nanofeatured polymeric films using nanosphere lithography and ultraviolet (UV) soft-mold roller embossing and show an illuminative example of their application to solar cells. To prepare the nanofeatured template, polystyrene nanocolloids of two distinct sizes (900 and 300 nm) were overlaid on silicon substrates using a spin coater. A lab-made soft-mold roller embossing device equipped with a UV light source was adopted. A casting method was employed to replicate the nanofeatured template onto polydimethylsiloxane, which was used as the soft mold. During the embossing procedure, the roller was driven by a step motor and compressed the UV-curable resin against the glass substrate to form the nanofeatured layer, which was subsequently cured by UV radiation. Polymer films with nanoscaled features were thus obtained. The influence of distinct processing variables on the reproducibility of the nanofeatured films was explored. The empirical outcomes demonstrate that UV soft-mold roller embossing offers a simple yet potent way of producing nanofeatured films.


1967 ◽  
Vol 50 (4) ◽  
pp. 847-849
Author(s):  
John Wiskerchen

Abstract A method is given for the quantitative determination of sodium lauryl sulfate in liquid, frozen, powdered, or flake-dried egg white. The egg white is dissolved in water and the protein is precipitated with ethanol and filtered off. The filtrate is evaporated, the residue is dissolved in water, and the pH is adjusted to 5.0. Total alkyl sulfates are titrated with standard benzethonium chloride solution in the presence of chloroform with bromphenol blue indicator. Results are calculated as sodium lauryl sulfate. The formation of the bromphenol bluebenzethonium chloride complex, when excess benzethonium chloride is present, is taken as the end point. The blue-green complex is soluble in the chloroform. Overall recoveries of sodium lauryl sulfate from egg whites ranged from 94 to 100%. Collaborative study of the method is recommended.


2015 ◽  
Vol 49 (3) ◽  
pp. 291-296 ◽  
Author(s):  
Gerald L. Vogel ◽  
Gary E. Schumacher ◽  
Laurence C. Chow ◽  
Livia M.A. Tenuta

Increasing the concentration of free fluoride in oral fluids is an important goal in the use of topical fluoride agents. Although sodium lauryl sulfate (SLS) is a common dentifrice ingredient, the influence of this ion on plaque fluid and salivary fluid fluoride has not been examined. The purpose of this study was to investigate the effect of SLS on these parameters and to examine the effect of this ion on total (or whole) plaque fluoride, an important source of plaque fluid fluoride after a sufficient interval following fluoride administration, and on total salivary fluoride, a parameter often used as a surrogate measure of salivary fluid fluoride. Ten subjects accumulated plaque for 48 h before rinsing with a 12 mmol/l NaF (228 µg/g F) rinse containing or not containing 0.5% (w/w) SLS. SLS had no statistically significant effect on total plaque and total saliva fluoride but significantly increased salivary fluid and plaque fluid fluoride (by 147 and 205%, respectively). These results suggest that the nonfluoride components of topical agents can be manipulated to improve the fluoride release characteristics from oral fluoride reservoirs and that statistically significant change may be observed in plaque fluid and salivary fluid fluoride concentrations that may not be observed in total plaque and total saliva fluoride concentrations.


Author(s):  
Shriram Pillapakkam ◽  
N. A. Musunuri ◽  
P. Singh

In this paper, we present a technique for freezing monolayers of micron and sub-micron sized particles onto the surface of a flexible thin film after the self-assembly of a particle monolayer on fluid-liquid interfaces has been improved by the process we have developed where an electric field is applied in the direction normal to the interface. Particles smaller than about 10 microns do not self-assemble under the action of lateral capillary forces alone since capillary forces amongst them are small compared to Brownian forces. We have overcome this problem by applying an electric field in the direction normal to the interface which gives rise to dipoledipole and capillary forces which cause the particles to arrange in a triangular pattern. The technique involves assembling the monolayer on the interface between a UV-curable resin and another liquid by applying an electric field, and then curing the resin by applying UV light. The monolayer becomes embedded on the surface of the solidified resin film.


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