Surfactant-treated graphene oxide in organic solvents and its application in photovoltaic cells

Yishan Wang,Shengyi Yang,Haowei Wang,Li Zhang,Haijuan Cheng,Bo He,Weile Li,Bingsuo Zou 한국물리학회 2017 Current Applied Physics Vol.17 No.3

In this paper, a simple and non-poisonous “surfactant treatment” method to prepare graphene oxide (GO) in organic solvents with good dispersibility was presented. As the surfactant molecules, didodecyldimethyla-mmonium bromide (DDAB) was attached onto the GO sheets via ionic interactions by mild sonication, the obtained GO:DDAB nanocomposites were then blended into copolymer Poly(3- hexylthiophene-2,5-diyl) (P3HT) [6,6]:-Phenyl C61 butyric acid methyl ester (PC61BM) as the active layer to fabricate bulk-heterojunction (BHJ) organic solar cells ITO/PEDOT:PSS/P3HT:PC61BM:(GO:DDAB)/ Ca/Al. The concentration of GO:DDAB in the active layer, a maximum power conversion efficiency (PCE) of 3.67% was obtained by blending 0.5 mg/mL GO:DDAB in the active layer, showing an efficiency increment of 13.35% as compared with that of the control device without doping GO:DDAB. The optimized OPVs with PTB7:PC71BM by adding GO:DDAB shows the PCE of 7.96%. Therefore, it paves a way to get high efficiency organic photovoltaic cells by directly blending surfactant-treated graphene oxide in organic solvent.

Antioxidant Activities of Various Extracts from Korean Yam

Yishan Duan,Gyeong-Hwuii Kim,Han-Soo Kim 한국유화학회 2016 한국응용과학기술학회지 Vol.33 No.1

The objective of this study was to investigate the antioxidant activity of Korean yam(Dioscorea batatas DECNE.) by different extraction solvents including 70% methanol, 70% ethanol and chloroform–methanol mixture (CM, 2:1, v/v). Raw yam was analyzed for its color property, total phenol content and antioxidant activity. Yam possessed high L* value and H° value, which were 81.64±2.59 and 83.36±0.15, respectively. Raw yam was found to have great antioxidant activity evaluated through ABTS [2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt] radical scavenging activity, DPPH (2,2-diphenyl-1-picrylhydrazyl) radical scavenging activity, reducing power, and ferric reducing antioxidant power. Total phenol contents of various extracts from raw yam increased in the following order: 70% methanol extract(37.62±0.88 mg CAE/g), 70% ethanol extract (43.38±0.66 mg CAE/g) and CM extract (67.17±0.12 mg CAE/g), respectively. The same trend was also could be found in the ABTS radical scavenging activity, DPPH radical scavenging activity and ferric reducing antioxidant power assays. These results implied that Korean yam might play an important role in antioxidation and serve as the bio-health functional food to take a good part in prevention of human diseases and aging.

Study on Physiologically Active Compounds and Antioxidant Activity of Korean Yam (Dioscorea batatas DECNE.)

Yishan Duan,Gyeong-Hwuii Kim,Han-Soo Kim 한국유화학회 2016 한국응용과학기술학회지 Vol.33 No.1

The bioactive compound and antioxidant property of Korean yam (Dioscorea batatas DECNE.) were studied using in vitro methods. Yam available in Korea was analyzed for lycopene, chlorophyll a, b, tannin, phytic acid and total saponin contents. 70% Methanol, 70% ethanol and chloroform–methanol mixture (CM, 2:1, v/v) were used to extract yam. Then the antioxidant activity evaluated through ferrous ion chelating activity, β-carotene bleaching method, lipid peroxidation inhibition and nitric oxide (NO) radical scavenging activity. 70% Methanol extract showed the highest ferrous ion chelating activity and NO radical scavenging activity. And CM extract was the most effective in inhibition of linoleic acid peroxidation evaluated by β-carotene bleaching assay and lipid peroxidation inhibition assay. Based on the results obtained, yam is a potential active ingredient that could be applied in antioxidation as well as bio-health functional food to take a good part in prevention of human diseases and aging.

Study on Antioxidant Activity of Thermal Treatment Yam (Dioscorea batatas DECNE.) by n-Butanol and Ethyl Acetate Extracts

Yishan Duan,Gyeong-Hwuii Kim,Han-Soo Kim 한국유화학회 2015 한국응용과학기술학회지 Vol.32 No.4

In Korea, yam with thermal treatment is widely used to produce tea and beverage, which appeals to all age groups. To better understand the antioxidative activity of thermal treatment yam (Dioscorea batatas DECNE.), n-butanol and ethyl acetate extracts were evaluated with different antioxidant testing system. Their antioxidant activities, including ABTS[2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt] radical scavenging activity, DPPH (2,2-diphenyl-1-picrylhydrazyl) radical scavenging activity, reducing power, and ferric reducing antioxidant power as well as total phenol contents were assessed in vitro. Results showed ethyl acetate extract (51.63±2.51 mg CAE/g) possessed similar total phenol content compared with n-butanol extract (53.93±1.00 mg CAE/g). Ethyl acetate extract also exhibited similarly stronger antioxidant activity compared with n-butanol extract apart from ABTS radical scavenging activity assay.

Nutritional Evaluation of Korean Yam

Yishan Duan,Gyeong-Hwuii Kim,Su-Jin Joung,Han-Soo Kim 한국유화학회 2016 한국응용과학기술학회지 Vol.33 No.2

The aim of this study was conducted to investigate the proximate and nutritional compositions including mineral, vitamin, amino acids and fatty acids in Korean yam (Dioscorea batatas DECNE.). Carbohydrate (68.1%) possessed the large single constituent of yam. Small amounts of crude protein (16.9%), crude ash (5.8%) and crude fat (2.0%) contents were found. Yam was found to be good sources of essential minerals such as K (1295.5 mg/100 g), Mg (115.3 mg/100g), Na (99.0 mg/100 g) and Ca (56.5 mg/100 g) but Zn (0.3 mg/100 g) content was low. Relatively abundant vitamin B1 (11.5 mg/100g) could be observed while vitamin A, B3 and B6 were not found. The amino acid analysis revealed that the yam was superior with respect to glutamic acid (1770.6 mg%), lysine (1210.6 mg%) and urea (550.9 mg%). Essential amino acids were calculated to be 2954.5 mg%. The amino acid profiles showed that yam to be limiting in valine and leusine. Palmitic acid and linoleic acid were the most predominant fatty acids with the value of 31.5% and 41.5%, respectively. And the polyunsaturated fatty acids including linoleic acid and linolenic acid were present in a large quantities in yam. And it also contained higher amounts of unsaturated fatty acids compared saturated fatty acids.

Antioxidant Activities of Various Extracts from Korean Yam (Dioscorea batatas DECNE.)

Yishan Duan,Gyeong-Hwuii Kim,Han-Soo Kim 한국유화학회 2016 한국응용과학기술학회지 Vol.33 No.2

The objective of this study was to investigate the antioxidant activity of Korean yam (Dioscorea batatas DECNE.) by different extraction solvents including 70% methanol, 70% ethanol and chloroform–methanol mixture (CM, 2:1, v/v). Raw yam was analyzed for its color property, total phenol content and antioxidant activity. Yam possessed high L* value and H° value, which were 81.64±2.59 and 83.36±0.15, respectively. Raw yam was found to have great antioxidant activity evaluated through ABTS [2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt] radical scavenging activity, DPPH (2,2-diphenyl-1-picrylhydrazyl) radical scavenging activity, reducing power, and ferric reducing antioxidant power. Total phenol contents of various extracts from raw yam increased in the following order: 70% methanol extract (37.62±0.88 mg CAE/g), 70% ethanol extract (43.38±0.66 mg CAE/g) and CM extract (67.17±0.12 mg CAE/g), respectively. The same trend was also could be found in the ABTS radical scavenging activity, DPPH radical scavenging activity and ferric reducing antioxidant power assays. These results implied that Korean yam might play an important role in antioxidation and serve as the bio-health functional food to take a good part in prevention of human diseases and aging.

Study on Physiologically Active Compounds and Antioxidant Activity of Korean Yam (Dioscorea batatas DECNE.)

Yishan Duan,Gyeong-Hwuii Kim,Han-Soo Kim 한국유화학회 2016 한국응용과학기술학회지 Vol.33 No.2

The bioactive compound and antioxidant property of Korean yam (Dioscorea batatas DECNE.) were studied using in vitro methods. Yam available in Korea was analyzed for lycopene, chlorophyll a, b, tannin, phytic acid and total saponin contents. 70% Methanol, 70% ethanol and chloroform–methanol mixture (CM, 2:1, v/v) were used to extract yam. Then the antioxidant activity evaluated through ferrous ion chelating activity, β-carotene bleaching method, lipid peroxidation inhibition and nitric oxide (NO) radical scavenging activity. 70% Methanol extract showed the highest ferrous ion chelating activity and NO radical scavenging activity. And CM extract was the most effective in inhibition of linoleic acid peroxidation evaluated by β-carotene bleaching assay and lipid peroxidation inhibition assay. Based on the results obtained, yam is a potential active ingredient that could be applied in antioxidation as well as bio-health functional food to take a good part in prevention of human diseases and aging.

Evaluation of Antioxidative activity of Korean Yam (Dioscorea batatas DECNE.) by n-Butanol and Ethyl Acetate Extracts

Yishan Duan,Han-Soo Kim,Gyeong-Hwuii Kim 한국유화학회 2015 한국응용과학기술학회지 Vol.32 No.2

In this study, n-butanol and ethyl acetate extracts were prepared from raw yam(Dioscorea batatas DECNE.). Their antioxidative potencies were investigated employing various in vitro methods, such as ferrous ion chelating, β-carotene bleaching assay, lipid peroxidation inhibition and nitric oxide (NO) radical scavenging and nitrite scavenging activity. The n-butanol fraction was assayed to possess stronger antioxidant activity by β-carotene bleaching assay, lipid peroxidation inhibition and NO radical scavenging activity. However, ethyl acetate extract was more effective in chelating ferrous ion and scavenging nitrite. Based on the results obtained, yam is a potential active ingredient that could be applied in antioxidation as well as bio-health functional food to take a good part in prevention of human diseases and aging.

Antioxidant Activities of n-Butanol and Ethyl Acetate Extracts from Yam (Dioscorea batatas DECNE.)

Yishan Duan,Gyeong-Hwuii Kim,Jong-Hwan Seong,Hun-Sik Chung,Han-Soo Kim 한국유화학회 2015 한국응용과학기술학회지 Vol.32 No.4

This study aimed at evaluating the antioxidant activity of raw yam (Dioscorea batatas DECNE.) extracted by n-butanol and ethyl acetate. The antioxidant activities, including ABTS [2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt] radical scavenging activity, DPPH (2,2-diphenyl-1-picrylhydrazyl) radical scavenging activity, reducing power, and ferric reducing antioxidant power as well as total phenol contents were studied in vitro. Results showed ethyl acetate extract (111.88±0.66 mg CAE/g) possessed higher total phenol content than n-butanol extract (78.68±0.58 mg CAE/g). Ethyl acetate extract exhibited stronger antioxidant activity compared with n-butanol extract apart from reducing power assay.

Antioxidant Activities of n-Butanol and Ethyl Acetate Extracts from Yam (Dioscorea batatas DECNE.)

Yishan Duan,Gyeong-Hwuii Kim,Jong-Hwan Seong,Hun-Sik Chung,Han-Soo Kim 한국유화학회 2015 한국응용과학기술학회지 Vol.32 No.4

This study aimed at evaluating the antioxidant activity of raw yam (Dioscorea batatas DECNE.) extracted by n-butanol and ethyl acetate. The antioxidant activities, including ABTS[2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt] radical scavenging activity, DPPH (2,2-diphenyl-1-picrylhydrazyl) radical scavenging activity, reducing power, and ferric reducing antioxidant power as well as total phenol contents were studied in vitro. Resultsshowed ethyl acetate extract (111.88±0.66 mg CAE/g) possessed higher total phenol content than n-butanol extract (78.68±0.58 mg CAE/g). Ethyl acetate extract exhibited stronger antioxidant activity compared with n-butanol extract apart from reducing power assay.