scholarly journals Surface Hydrophobic Modification of Microcrystalline Cellulose by Poly(methylhydro)siloxane Using Response Surface Methodology

Polymers ◽  
2018 ◽  
Vol 10 (12) ◽  
pp. 1335 ◽  
Author(s):  
Yulin Xie ◽  
Siquan Cai ◽  
Zhen Hou ◽  
Weihua Li ◽  
Yan Wang ◽  
...  

Poly(methylhydro)siloxane (PMHS) and n-hexane were used as modifiers and solvents, respectively, to prepare surface modification of microcrystalline cellulose (MCC). The response surface methodology was used to optimize the effects of reaction conditions on hydrophobicity of MCC. The optimal reaction conditions were determined as follows: the concentration of PMHS was 0.0275% (the mass ratio of PMHS to MCC), the reaction time was 20 min, and the drying temperature was 70 °C. Under the optimum reaction conditions, the water contact angle of modified MCC was 141.5°. It is feasible to optimize and select the reaction conditions of modified MCC by Design-Expert, and the predicted value of the mathematical model is in good agreement with the experimental value. Surface chemical characteristics were investigated using X-ray photoelectron spectroscopy (XPS). These analyses confirmed that the PMHS chains were attached to MCC. Due to the introduction of a large amount of methyl groups, the reaction between MCC and PMHS leads to an improvement in its hydrophobicity.

Water ◽  
2020 ◽  
Vol 12 (12) ◽  
pp. 3583
Author(s):  
Junying Yang ◽  
Minye Huang ◽  
Shengsen Wang ◽  
Xiaoyun Mao ◽  
Yueming Hu ◽  
...  

In this study, a magnetic copper ferrite/montmorillonite-k10 nanocomposite (CuFe2O4/MMT-k10) was successfully fabricated by a simple sol-gel combustion method and was characterised by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), the Brunner–Emmett–Teller (BET) method, vibrating sample magnetometer (VSM), and X-ray photoelectron spectroscopy (XPS). For levofloxacin (LVF) degradation, CuFe2O4/MMT-k10 was utilized to activate persulfate (PS). Due to the relative high adsorption capacity of CuFe2O4/MMT-k10, the adsorption feature was considered an enhancement of LVF degradation. In addition, the response surface methodology (RSM) model was established with the parameters of pH, temperature, PS dosage, and CuFe2O4/MMT-k10 dosage as the independent variables to obtain the optimal response for LVF degradation. In cycle experiments, we identified the good stability and reusability of CuFe2O4/MMT-k10. We proposed a potential mechanism of CuFe2O4/MMT-k10 activating PS through free radical quenching tests and XPS analysis. These results reveal that CuFe2O4/MMT-k10 nanocomposite could activate the persulfate, which is an efficient technique for LVF degradation in water.


2015 ◽  
Vol 4 (4) ◽  
Author(s):  
Seyed Mohammad Safieddin Ardebili ◽  
Teymor Tavakoli Hashjin ◽  
Barat Ghobadian ◽  
Gholamhasan Najafi ◽  
Stefano Mantegna ◽  
...  

AbstractThis work investigates the effect of simultaneous ultrasound-microwave irradiation on palm oil transesterification and uncovers optimal operating conditions. Response surface methodology (RSM) has been used to analyze the influence of reaction conditions, including methanol/palm oil molar ratio, catalyst concentration, reaction temperature and irradiation time on biodiesel yield. RSM analyses indicate 136 s and 129 s as the optimal sonication and microwave irradiation times, respectively. Optimized parameters for full conversion (97.53%) are 1.09% catalyst concentration and a 7:3.1 methanol/oil molar ratio at 58.4°C. Simultaneous ultrasound-microwave irradiation dramatically accelerates the palm oil transesterification reaction. Pure biodiesel was obtained after only 2.2 min while the conventional method requires about 1 h.


2013 ◽  
Vol 2013 ◽  
pp. 1-9 ◽  
Author(s):  
Yu-Bin Ji ◽  
Fang Dong ◽  
Miao Yu ◽  
Long Qin ◽  
Dan Liu

The response surface methodology was employed to optimize the synthesis conditions of seleno-Sargassum fusiforme(Harv.) Setch. polysaccharide. Three independent variables (reaction time, reaction temperature, and ratio of Na2SeO3to SFPSI) were tested. Furthermore, the characterization and antioxidant activity of Se-SFPSIin vivowere investigated. The result showed that the actual experimental Se content of Se-SFPSI was 3.352 mg/g at the optimum reaction conditions of reaction time 8 h, reaction temperature 71°C, and ratio of Na2SeO3to SFPSIB 1.0 g/g. A series of experiments showed that the characterization of Se-SFPSIB was significantly different from that of SFPSIB. Additionally, antioxidant activity assay indicated that the Se-SFPSIB could increase catalase (CAT), superoxide dismutase (SOD), and glutathione peroxidase (GSH-Px) activity of mice bearing tumor S180in blood, heart, and liver while decreasing malondialdehyde (MDA) levels. It can be concluded that selenylation is a feasible approach to obtain seleno-polysaccharide which was utilized as highly biological medicine or functional food.


Processes ◽  
2021 ◽  
Vol 9 (1) ◽  
pp. 117
Author(s):  
Muhammad Ali Inam ◽  
Rizwan Khan ◽  
Ick Tae Yeom ◽  
Abdul Salam Buller ◽  
Muhammad Akram ◽  
...  

Coprecipitation-adsorption plays a significant role during coagulation-flocculation-sedimentation (C/F/S) of antimony (Sb) in water. This work uses a Box–Behnken statistical experiment design (BBD) and response surface methodology (RSM) to investigate the effects of major operating variables such as initial Sb(III, V) concentration (100–1000 µg/L), ferric chloride (FC) dose (5–50 mg/L), and pH (4–10) on redox Sb species. Experimental data of Sb(III, V) removal were used to determine response function coefficients. The model response value (Sb removal) showed good agreement with the experimental results. FC showed promising coagulation behavior of both Sb species under optimum pH (6.5–7.5) due to its high affinity towards Sb species and low residual Fe concentration. However, a high dose of 50 mg/L of FC is required for the maximum (88–93%) removal of Sb(V), but also for the highest (92–98%) removal of low initial concentrations of Sb(III). Furthermore, BBD and RSM were found to be reliable and feasible for determining the optimum conditions for Sb removal from environmental water samples by a C/F/S process. This work may contribute to a better understanding and prediction of the C/F/S behavior of Sb(III, V) species in aqueous environments, to reduce potential risks to humans.


2021 ◽  
Vol 52 (1) ◽  
pp. 204-217
Author(s):  
Mohammed & Mohammed-Ridha

This study was aimed to investigate the response surface methodology (RSM) to evaluate the effects of various experimental conditions on the removal of levofloxacin (LVX) from the aqueous solution by means of electrocoagulation (EC) technique with stainless steel electrodes. The EC process was achieved successfully with the efficiency of LVX removal of 90%. The results obtained from the regression analysis, showed that the data of experiential are better fitted to the polynomial model of second-order with the predicted correlation coefficient (pred. R2) of 0.723, adjusted correlation coefficient (Adj. R2) of 0.907 and correlation coefficient values (R2) of 0.952. This shows that the predicted models and experimental values are in good agreement. The results of the kinetic study showed that the second-order kinetic model was in good agreement with the experimental results and suggested that the mechanism of chemisorption controlled the LVX adsorption. The experimental results indicated that the adsorption of LVX on iron hydroxide flocs follows Sips isotherm with the value of the correlation coefficient (R2) of 0.937. Sips isotherm shows that both homogenous and heterogeneous adsorption can occur.


2020 ◽  
Vol 15 (3) ◽  
pp. 604-616
Author(s):  
Girish Basavaraju ◽  
Ravishankar Rajanna

A custom-made tubular flow reactor was utilized to develop a mathematical model and optimize the Suzuki-Miyaura cross coupling reaction. In this study, the experimentation was designed and executed through the statistical design of experiments (DoE) approach via response surface methodology. The effect of molar ratios of phenylboronic acid (1) and 4-bromophenol (2), temperature, the catalyst tetrakis(triphenylphosphine)palladium, and equivalence of aqueous tripotassium phosphate was studied in detail. The flow reactor profile was in good agreement with batch conditions and significant improvements to the overall reaction time and selectivity towards desired [1-1-biphenyl]-4-ol (3) was achieved. The Suzuki coupling reaction in batch condition would take on an average of 4 to 6 hours to complete, which was effectively accomplished in 60 to 70 minutes in this tubular reactor setup and could be operated continuously. The reaction model is in good agreement with the reaction conditions. Copyright © 2020 BCREC Group. All rights reserved 


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