Study on the Wood-Based Hydrogel and its pH-Sensitivity

2010 ◽  
Vol 139-141 ◽  
pp. 1950-1953
Author(s):  
Jiu Fang Duan ◽  
Jian Zhang Li
Keyword(s):  
Water Absorption ◽  
Chloride Solution ◽  
Sodium Chloride Solution ◽  
Ph Value ◽  
Ph Sensitivity ◽  
Swelling Ratio ◽  
Buffer Solution ◽  
Monomer Ratio ◽  
Crosslinker Content ◽  
Wood Content

A water absorbent wood hydrogel was prepared with the wood and acrylamide using glutaraldehyde as crosslinker. The structure of wood-based hydrogel was charactered by FTIR spectra. The monomer ratio, the amount of glutaraldehyde, the behavior of pH-sensitivity and salt-sensitivity of the wood hydrogel were studied in this paper. The results are as follows: The water absorption and grafting yield of wood-based hydrogel decreased with the increasing of wood content. The water absorption of wood-based hydrogel decreased with the crosslinker content increasing, the grafting yield increases with the crosslinker content increasing. The water absorption of wood-based hydrogel has strong sensitivity in pH value of 3.0 ~ 11.0 solution. At acidic and alkaline larger environment, the hydrogel shows a larger water absorption, and the smallest swelling ratio was obtained in pH7.0 buffer solution. The wood-based hydrogel shows stable behavior in different concentrations of sodium chloride solution.

Corrosion Resistance of High-Alloyed Material UNS N08028 in Sodium Chloride Solution

2014 ◽  
Vol 893 ◽  
pp. 440-443
Author(s):  
Li Na Zhang ◽  
Jerzy A. Szpunar ◽  
Jian Xin Dong ◽  
Mai Cang Zhang
Keyword(s):  
Corrosion Resistance ◽  
Sodium Chloride ◽  
Corrosion Rate ◽  
Current Density ◽  
Chloride Solution ◽  
Sodium Chloride Solution ◽  
Corrosion Potential ◽  
Ph Value ◽  
Chloride Concentration ◽  
Decreasing Ph

The influence of ions chloride concentration and pH value on the corrosion resistance of high-alloyed material UNS N08028 in the sodium chloride solution is investigated. Results show that the corrosion potential is active cathodically with the increase of chloride concentration. The current density and corrosion rate both increase with increasing chloride concentration and decreasing pH value.

Study on the Swelling and Deswelling of the PH / Thermosensitive Hydrogel

2011 ◽  
Vol 55-57 ◽  
pp. 1-6 ◽  
Author(s):  
Xiu Fang Zhu ◽  
Wei Zhou ◽  
Hong Xia Zhang ◽  
Yu Jing Nie
Keyword(s):  
Ionic Strength ◽  
Ph Value ◽  
Point Of View ◽  
Ion Concentration ◽  
Swelling Ratio ◽  
Buffer Solution ◽  
Thermosensitive Hydrogel ◽  
Temperature Responsive ◽  
Ph Buffer Solution ◽  
Ph Buffer

From the point of view of molecule design, pH/temperature responsive hydrogels were prepared based on the acrylic acid with the excellent pH sensitivity and N-isopropylacrylamide (NIPA) with the excellent temperature sensitivity by the traditional radical polymerization. Study focus on the swelling of the hydrogels, measurement of the swelling and deswelling under different ionic strength with various temperatures of the hydrogels were performed in our work. The results show that the ionic strength, the pH value and temperature are three key factors that affect the LCST of the hydrogel. In the same pH buffer solution, the swelling ratio decreases with temperature rises, and the ionic strength greatly affects the swelling of the pH temperature responsive hydrogel, the higher the ion concentration is, the lower the swelling ratio and the LCST are.

Improving Topical Skin Delivery of Monocrotaline Via Liposome Gel-based Nanosystems

2019 ◽  
Vol 16 (10) ◽  
pp. 940-950 ◽  
Author(s):  
Jiandong Yu ◽  
Zhi Chen ◽  
Yan-zhi Yin ◽  
Chaoyuan Tang ◽  
Enying Hu ◽  
...  
Keyword(s):  
Gradient Method ◽  
Encapsulation Efficiency ◽  
Ph Value ◽  
Topical Administration ◽  
Ph Gradient ◽  
Stability Factor ◽  
Buffer Solution ◽  
Skin Delivery ◽  
Skin Retention

Background: In this study, a liposomal gel based on a pH-gradient method was used to increase the skin-layer retention of monocrotaline (MCT) for topical administration. Methods: Using the Box-Behnken design, different formulations were designed to form liposome suspensions with optimal encapsulation efficiency (EE%) and stability factor (KE). In order to keep MCT in liposomes and accumulate in skin slowly and selectively, MCT liposome suspensions were engineered into gels. Results: A pH-gradient method was used to prepare liposome suspensions. The optimal formulation of liposome suspensions (encapsulation efficiency: 83.10 ± 0.21%) was as follows: MCT 12 mg, soybean phosphatidyl choline (sbPC) 200 mg, cholesterol (CH) 41 mg, vitamin E (VE) 5 mg, and citric acid buffer solution (CBS) 4.0 10 mL (pH 7.0). The final formulation of liposomal gels consisted of 32 mL liposome suspensions, 4.76 mL deionized water, 0.40 g Carbopol-940, 1.6 g glycerol, 0.04 g methylparaben, and a suitable amount of triethanolamine for pH value adjustment. The results of in vitro drug release showed that MCT in liposomal gels could be released in 12 h constantly in physiological saline as a Ritger-Peppas model. Compared with plain MCT in gel form, liposomal MCT in gel had higher skin retention in vitro. Conclusion: In this study, liposomal gels were formed for greater skin retention of MCT. It is potentially beneficial for reducing toxicities of MCT by topical administration with liposomal gel.

scholarly journals Physical and mechanical properties of rubberwood (Hevea brasiliensis) dyed with Lasiodiplodia theobromae

2019 ◽  
Vol 65 (1) ◽  
Author(s):  
Boshi Zhao ◽  
Zhiming Yu ◽  
Yang Zhang ◽  
Chusheng Qi
Keyword(s):  
Mass Loss ◽  
Water Absorption ◽  
Hevea Brasiliensis ◽  
Ph Value ◽  
Energy Dispersive Spectrometer ◽  
Physical And Mechanical Properties ◽  
Blue Staining ◽  
Loss Ratio ◽  
Lasiodiplodia Theobromae ◽  
Infrared Spectrometer

AbstractBlue staining on rubberwood (Hevea brasiliensis) is a common kind of defect. There currently exists much research focused on the prevention and control of blue staining. However, little research has been concentrated on the utilization of blue staining for green dyeing. The research conveyed in this paper primarily used Lasiodiplodia theobromae to dye rubberwood, and used scanning electron microscope (SEM), energy-dispersive spectrometer (EDS), X-ray diffraction (XRD), and fourier transform infrared spectrometer (FTIR) to analyze the commission internationale eclairage (CIE) L*a*b* value of color, the contact angle, the pH value, 24-h water absorption, mass loss ratio, and compressive strength in increments between 5 and 40 days. The results found that the color of rubberwood became darker and more uniform, and that the surface dyed with fungi can reach a super-hydrophobic state. With the increase of time, the pH value of rubberwood changed from acidic to alkaline. Furthermore, hyphae entered the wood mainly through vessels for their large pore diameter, and reduced water absorption. Mass loss ratio increased gradually between 5 and 40 days. The research in this paper concludes that the microorganism was an effective method of wood dyeing, and lays a foundation for further research.

scholarly journals The use of Robinia pseudoacacia L fruit extract as a green corrosion inhibitor in the protection of copper-based objects

2021 ◽  
Vol 9 (1) ◽  
Author(s):  
Vahid Pourzarghan ◽  
Bahman Fazeli-Nasab
Keyword(s):  
Sodium Chloride ◽  
Corrosion Inhibition ◽  
Aqueous Extract ◽  
Chloride Solution ◽  
Sodium Chloride Solution ◽  
Control Sample ◽  
Fruit Extract ◽  
Bronze Alloy ◽  
Sem Images ◽  
Green Inhibitor

AbstractThe most important inhibitors used in bronze disease are BTA and AMT. While these inhibitors control corrosion, they are toxic and cancerous. In this study, the acacia fruit extract (200 ppm to 1800 ppm) was used to the prevention of corrosion inhibition of bronze alloy in corrosive sodium chloride solution 0.5 M, for 4 weeks consecutively. The Bronze alloy used in this research, was made based on the same percentage as the ancient alloys (Cu-10Sn). IE% was used to obtain the inhibitory efficiency percentage and Rp can be calculated from the resistance of polarization. SEM–EDX was used to evaluate the surfaces of alloy as well as inhibitory. The experiment was conducted in split plot design in time based on the RCD in four replications. ANOVA was performed and comparison of means square using Duncan's multiple range test at one percent probability level. The highest rate of corrosion inhibition (93.5%) was obtained at a concentration of 1800 ppm with an increase in the concentration of the extract, corrosion inhibition also increased, i.e., more bronze was prevented from burning. Also, the highest corrosion inhibitory activity of Acacia extract (79.66) was in the second week and with increasing duration, this effect has decreased. EDX analysis of the control sample matrix showed that the amount of chlorine was 8.47%wt, while in the presence of corrosive sodium chloride solution, after 4 weeks, the amount of chlorine detected was 3.20%wt. According to the morphology (needle and rhombus) of these corrosion products based on the SEM images, it can be said, they are the type of atacamite and paratacamite. They have caused bronze disease in historical bronze works. The green inhibitor of Acacia fruit aqueous extract can play an effective role in inhibiting corrosion of bronze, but at higher concentrations, it became fungal, which can reduce the role of Acacia fruit aqueous extract and even ineffective. To get better performance of green inhibitors, more tests need to be done to improve and optimize.

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