Enhanced proton conductivity of proton exchange membranes by incorporating phosphorylated hollow titania spheres

RSC Advances ◽  
2016 ◽  
Vol 6 (72) ◽  
pp. 68407-68415 ◽  
Author(s):  
Li Cao ◽  
Xiaohui Shen ◽  
Xin Yang ◽  
Bei Zhang ◽  
Zongyu Li ◽  
...  
Keyword(s):  
Proton Transfer ◽  
Proton Conductivity ◽  
Water Retention ◽  
Proton Exchange Membranes ◽  
Proton Exchange ◽  
Water Retention Capacity ◽  
Hybrid Membranes ◽  
Retention Capacity ◽  
Synergistic Enhancement

The synergistic enhancement in proton conductivity of hybrid membranes by improving the water retention capacity and introducing additional proton transfer sites is reported.

Enhanced water retention and proton conductivity of proton exchange membranes by incorporating hollow polymer microspheres grafted with sulfonated polystyrene brushes

RSC Advances ◽  
2015 ◽  
Vol 5 (7) ◽  
pp. 5343-5356 ◽  
Author(s):  
Wei Zhang ◽  
Bei Zhang ◽  
Guangwei He ◽  
Bin Liu ◽  
Zhongyi Jiang ◽  
...  
Keyword(s):  
Proton Conductivity ◽  
Water Retention ◽  
Proton Exchange Membranes ◽  
Proton Exchange ◽  
Polymer Microspheres ◽  
Sulfonated Polystyrene

The paper describes the synthesis of hollow polymer microspheres with sulfonated polystyrene brushes and investigation of the enhanced water retention and proton conductivity of proton exchange membranes.

scholarly journals Synthesis and Characterization of Partially Renewable Oleic Acid-Based Ionomers for Proton Exchange Membranes

Polymers ◽  
2020 ◽  
Vol 13 (1) ◽  
pp. 130
Author(s):  
Carlos Corona-García ◽  
Alejandro Onchi ◽  
Arlette A. Santiago ◽  
Araceli Martínez ◽  
Daniella Esperanza Pacheco-Catalán ◽  
...  
Keyword(s):  
Oleic Acid ◽  
Proton Conductivity ◽  
Electrochemical Impedance ◽  
Proton Exchange Membranes ◽  
Proton Exchange ◽  
Molar Ratio ◽  
Aromatic Diamines ◽  
Chemical Structures ◽  
Long Chain

The future availability of synthetic polymers is compromised due to the continuous depletion of fossil reserves; thus, the quest for sustainable and eco-friendly specialty polymers is of the utmost importance to ensure our lifestyle. In this regard, this study reports on the use of oleic acid as a renewable source to develop new ionomers intended for proton exchange membranes. Firstly, the cross-metathesis of oleic acid was conducted to yield a renewable and unsaturated long-chain aliphatic dicarboxylic acid, which was further subjected to polycondensation reactions with two aromatic diamines, 4,4′-(hexafluoroisopropylidene)bis(p-phenyleneoxy)dianiline and 4,4′-diamino-2,2′-stilbenedisulfonic acid, as comonomers for the synthesis of a series of partially renewable aromatic-aliphatic polyamides with an increasing degree of sulfonation (DS). The polymer chemical structures were confirmed by Fourier transform infrared (FTIR) and nuclear magnetic resonance (1H, 13C, and 19F NMR) spectroscopy, which revealed that the DS was effectively tailored by adjusting the feed molar ratio of the diamines. Next, we performed a study involving the ion exchange capacity, the water uptake, and the proton conductivity in membranes prepared from these partially renewable long-chain polyamides, along with a thorough characterization of the thermomechanical and physical properties. The highest value of the proton conductivity determined by electrochemical impedance spectroscopy (EIS) was found to be 1.55 mS cm−1 at 30 °C after activation of the polymer membrane.

A Study of the Nitrogen-Containing Heterocycles on Copolyimide Properties for Proton Exchange Membranes

2013 ◽  
Vol 401-403 ◽  
pp. 563-566 ◽  
Author(s):  
Yu Han Li ◽  
Wei Jian Wang ◽  
Yu Fei Chen ◽  
Lei Wang
Keyword(s):  
Mechanical Properties ◽  
Thermal Stability ◽  
Proton Conductivity ◽  
Water Uptake ◽  
Main Chain ◽  
Proton Exchange Membranes ◽  
Proton Exchange ◽  
Membrane Properties ◽  
Dimensional Changes ◽  
Sulfonated Polyimide

Containing pyrimidine and pyridine monomers were incorporated respectively into the main chain of a sulfonated polyimide in order to investigate the effect of nitrogen-containing heterocycles on membrane properties such as water uptake and proton conductivity. With increasing content of the nitrogen-containing heterocycles, water uptake of membranes and dimensional changes remarkable decrease. The copolymer showed higher thermal stability (desulfonation temperature up to 330 °C) and reasonable good mechanical properties. These membranes also showed higher proton conductivity, which was comparable or even higher than Nafion 117.

scholarly journals Chemical Composition and Functional Properties of Dietary Fibre Concentrates from Winemaking By-Products: Skins, Stems and Lees

Foods ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 1510
Author(s):  
María Ángeles Rivas ◽  
Rocío Casquete ◽  
María de Guía Córdoba ◽  
Santiago Ruíz-Moyano ◽  
María José Benito ◽  
...  
Keyword(s):  
Chemical Composition ◽  
Functional Properties ◽  
Dietary Fibre ◽  
Water Retention ◽  
Point Of View ◽  
Water Retention Capacity ◽  
Retention Capacity ◽  
Oil Retention ◽  
High Antioxidant Activity ◽  
By Products

The objective of this study was to evaluate, from a technological and nutritional point of view, the chemical composition and functional properties of the industrial winemaking by-products, namely skins, stems and lees. The chemical and physical characteristics, as well as the functional properties (fat and water retention and swelling capacity, antioxidant capacity, and their prebiotic effect), of the dietary fibre of these by-products were studied. The results showed that the skins, stems, and lees are rich in fibre, with the stem fibre containing the highest amounts of non-extractable polyphenols attached to polysaccharides with high antioxidant activity and prebiotic effect. Lee fibre had the highest water retention capacity and oil retention capacity. The results reveal that winemaking by-products could be used as a source of dietary fibre with functional characteristics for food applications.

Host preferences of low-trunk vascular epiphytes in a cloud forest of Veracruz, Mexico

2005 ◽  
Vol 21 (6) ◽  
pp. 651-660 ◽  
Author(s):  
Klaus Mehltreter ◽  
Alejandro Flores-Palacios ◽  
José G. García-Franco
Keyword(s):  
Water Retention ◽  
Cloud Forest ◽  
Water Retention Capacity ◽  
Retention Capacity ◽  
Host Preferences ◽  
Host Group ◽  
Vascular Epiphytes ◽  
Lower Trunk ◽  
Tree Ferns ◽  
Epiphyte Species

The diversity, abundance and frequency of vascular epiphytes on the lower trunk were compared between two host groups of a Mexican cloud forest: angiosperm trees (n = 72) and tree ferns (n = 28). The bark of the five most frequent host trees and the root mantle of the two tree ferns were analysed for their thickness, water content, water retention capacity and pH. A total of 55 epiphyte species and 910 individuals were found on the 27 host species. On hosts with a dbh range of 5–10 cm, epiphytes were significantly more diverse (4.3±0.9 species per host) and more abundant (12.5±2.2 individuals per host) on tree ferns than on angiosperm trees (1.9±0.2 species per host and 3.9±0.6 individuals per host). However, these differences were not significant for the dbh class of 10–20 cm, because epiphyte numbers increased on angiosperm trees with larger host size, but not in tree ferns. Most epiphyte species had no preference for any host group, but four species were significantly more frequent on tree ferns and two species on angiosperm trees. The higher epiphyte diversity and abundance on tree fern trunks of the smallest dbh class is attributed to their presumably greater age and to two stem characteristics, which differed significantly between host groups, the thicker root mantle and higher water retention capacity of tree ferns. These bark characteristics may favour germination and establishment of epiphytes.

Effect of boiling on nutritional, antioxidant and physicochemical properties of edible plants (Malva parviflora and Myrtillocactus geometrizans)

2021 ◽  
pp. 510
Author(s):  
Sandoval-Gallegos Eli Mireya ◽  
Arias-Rico José ◽  
Cruz-Cansino Nelly del Socorro ◽  
Ramírez-Ojeda Deyanira ◽  
Zafra-Rojas Quinatzin Yadira ◽  
...  
Keyword(s):  
Phenolic Compounds ◽  
Physicochemical Properties ◽  
Antioxidant Capacity ◽  
Water Retention ◽  
Nutritional Composition ◽  
Total Phenolic ◽  
Water Retention Capacity ◽  
Total Phenolic Compounds ◽  
Retention Capacity ◽  
Malva Parviflora

The aim of the present research was to determine the effect of boiling on nutritional composition, total phenolic compounds, antioxidant capacity, physicochemical and morphological characteristics of two edible plants Malva parviflora (mallow leaf) and Myrtillocactus geometrizans (garambullo flower). The plants had an important nutritional composition as carbohydrates (48-70 %), dietary fiber (36-42 %) and protein (13 %), as well as total phenolic compounds (468-750 mg GAE/100 g db) with a high antioxidant capacity. However, boiling originated the decrease of soluble compounds, carbohydrates, total phenolic compounds, antioxidant capacity and physicochemical properties. Plants changed to dark colors and physicochemical properties were affected, except to water retention capacity, oil retention capacity and viscosity, which had the same values in mallow leaves (raw and boiled), but increased water retention capacity in garambullo flowers, it may be by changes in the morphology observed. Therefore, is to suggest the raw consumption or with minimal cooking of these plants to avoid changes caused by thermal treatment.

Effect of Storage Time on the Physicochemical and Sensory Properties of Man-tou (Chinese Steamed Bread)

2007 ◽  
Vol 3 (3) ◽  
Author(s):  
Kun Sha ◽  
Ping Qian ◽  
Li-Jun Wang ◽  
Zhan-hui Lu ◽  
Li-Te Li
Keyword(s):  
Water Retention ◽  
Storage Time ◽  
Soluble Starch ◽  
Prolonged Storage ◽  
Water Retention Capacity ◽  
Study Quality ◽  
Total Water ◽  
Retention Capacity ◽  
Steamed Bread

In this study, quality of Man-tou, the Chinese traditional steamed bread during storage was studied. Values for water retention capacity, total water solubles, soluble starch, and soluble amylose and amylopectin of Man-tou decreased with storage time. Results showed that hardness, chewiness and gumminess of Man-tou increased, while, springiness cohesiveness and resilience decreased along with prolonged storage time (p<0.05). Sensory evaluation results showed that all sensory rating of Man-tou, including softness, stickiness, cohesiveness, elasticity, taste and total score, dropped drastically within 24 h of storage time (p<0.05). Differential Scanning Calorimeter (DSC) was used to determine crystalline structure of amylopectin in Man-tou, and the value for enthalpy of crystallization was found increased with storage time. Amylopectin crystallization was significantly associated to Man-tou firming (p<0.01).

scholarly journals Cowpea bean production under water stress using hydrogels

2017 ◽  
Vol 47 (1) ◽  
pp. 87-92 ◽  
Author(s):  
Marília Barcelos Souza Lopes ◽  
Taynar Coelho de Oliveira Tavares ◽  
Danilo Alves Veloso ◽  
Niléia Cristina da Silva ◽  
Rodrigo Ribeiro Fidelis
Keyword(s):  
Water Stress ◽  
Water Use ◽  
Food Production ◽  
Water Retention ◽  
Block Design ◽  
Population Increase ◽  
Water Retention Capacity ◽  
Yield Losses ◽  
Retention Capacity ◽  
Randomized Block Design

ABSTRACT The population increase and the need of intensifying food production, coupled with the scarcity of water resources, have led to the search of alternatives that reduce consumption and optimize the water use during cultivation. In this context, hydrogels become a strategy in agricultural management, due to their water retention capacity in the soil and availability to plants. This study aimed at evaluating the efficiency of hydrogels on the development and production of cowpea bean ('Sempre-verde' cultivar) under water stress, in a greenhouse. The experiment was performed in a randomized block design, with five replications, in a 4 x 5 factorial scheme, consisting of four types of hydrogel (Hydroplan-EB HyA, with granulometry of 1-3 mm; Hydroplan-EB HyB, with granulometry of 0.5-1 mm; Hydroplan-EB HyC, with granulometry < 0.5 mm; Polim-Agri, with granulometry of 1-0.5 mm) and five concentrations (0 g pot-1; 1.5 g pot-1; 3 g pot-1; 4.5 g pot-1; 6 g pot-1). The following traits were evaluated: number of pods per plant, number of grains per pod and grain yield. The highest concentration (6 g pot-1) resulted in a higher number of pods and yield for all the hydrogels, especially for HyC and Polim-Agro, which presented 7.4 pods plant-1 and 7.0 pods plant-1, with yield of 15.43 g plant-1 and 16.68 g plant-1, respectively. The use of hydrogel shows to be efficient for reducing yield losses under water stress.

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