جستجوی مقالات مرتبط با کلیدواژه "swelling" در نشریات گروه "شیمی"

Hydrogels are three dimensional polymers that do not dissolve in water, but they swell. One of the most important physical properties of hydrogels is their swelling in water [1]. Polyvinylpyrrolidone is widely used for its biocompatibility behavier [2]. Methacrylic acid also has many uses due to its COOH group. In this project, co hydrogel (vinyl pyrrolidone-methacrylic acid) was prepared by using free radical polymerization at 65 ° C for 5 hours and45 minutes using AIBN as a initiator and methylene bis acrylamide as a crosslinking agent. Then, at different pH and different temperatures and intensity of different ions, the maximum swelling at pH = 12 and in the ratio 1: 1,8000%, and the minimum swelling at pH=12 in ratio 1:2 was obtained. To identify the structure we use FTIR and for thermal identification we use T.G.A. And the maximum degradation for these hydrogels was at 75 ° C due to the high swelling rate.

Malva sylvestris is one of the most important plants used in pharmaceutical and cosmetic industries is the health of most developed countries. The juice is a potent anti-oxidant strong disinfectant. The leaves and flowers of this plant have a great application in the provision of Medicine and treatment in traditional medicine. In this research, Malva sylvestris was collected from the Anzan Meshgin-Shahr area in the northwest of Iran. The essential oil was extracted by Clevenger's apparatus, GC and GC/MS devices were used for analysis of essential oil compounds and accurate measurements of the compounds. Then, the effect of the essential oil of the Malva sylvestris and  control on the common bacteria of the oral infection evaluated in two ways: Disc deffusion And minimum inhibitory concentration (MIC). According to the results, the essential oil of the herb has a significant inhibitory effect on the types of gram negative and positive bacteria. Also, comparing the diameter of the non-growth of the plant with chlorhexin, it was found that the essence of the herb medicine showed relatively similar results to that of the chlorhexin.  According to the findings, essential oil of the herb has a good anti-microbial effect against the common bacteria of oral infections. As a result, the essential oil of this plant with different concentrations, after completing studies, can be an appropriate alternative for chemical drugs and chemical mouthwashes in the treatment of oral bacterial infections.

Hydrogels are three-dimensional polymers that do not dissolve in water but swell. one of the most important physical properties of hydrogels is their swelling in water. Polyvinyl pyrrolidone has a wide range of applications due to its biocompatibility. methacrylic acid also has many uses due to its COOH group. In this project, using free radical polymerization at 65 °C for 5 hours and 45 minutes, using AIBN as an initiator and methylene bisacrylamide as a crosslinking agent, cohydrogels (vinyl pyrrolidone-methacrylic acid) were prepared and at different pH, temperature and intensity of ions were examined. The maximum inflation was obtained at pH = 12 and in the ratio of 1:1 equal to 8000% and the minimum inflation was obtained at pH = 2 in the ratio of 1: 2. FTIR was used for structural identification and T.G.A. for thermal identification, the maximum degradation for these hydrogels was at 75 ° C, due to high swelling.