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Статті в журналах з теми "GUAR GUM HYDROGEL"
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Pak, Sol-Ju, and Fang Chen. "Functional Enhancement of Guar Gum−Based Hydrogel by Polydopamine and Nanocellulose." Foods 12, no. 6 (March 18, 2023): 1304. http://dx.doi.org/10.3390/foods12061304.
Повний текст джерелаАнотація:
The development of green, biomedical hydrogels using natural polymers is of great significance. From this viewpoint, guar gum (GG) has been widely used for hydrogel preparation; however, its mechanical strength and adhesion often cannot satisfy the biomedical application. Therefore, in the present study, gelatin and a cellulose nanocrystal (CNC) were first applied to overcome the defects of guar gum hydrogel. Dopamine was self−polymerized into polydopamine (PDA) on the gelatin chain at alkaline condition, and gelatin−polydopamine (Gel−PDA) further cross−linked with guar gum and CNC via the borate−didiol bond, intramolecular Schiff base reaction, and Michael addition. CNC not only interacted with guar gum using borate chemistry but also acted as a mechanical reinforcer. The obtained Gel−PDA+GG+CNC hydrogel had an excellent self−healing capacity, injectability, and adhesion due to the catechol groups of PDA. Moreover, dopamine introduction caused a significant increase in the anti−oxidant activity. This hydrogel was cyto− and hemo−compatible, which implies a potential usage in the medical field.
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Xiong, Yun, Xu Zhang, and Ming Zhu Liu. "Surface-Crosslinked Guar Gum-g-Sodium Polyacrylate Superabsorbents: Swelling Characteristics and Mechanics Performance." Applied Mechanics and Materials 729 (January 2015): 39–46. http://dx.doi.org/10.4028/www.scientific.net/amm.729.39.
Повний текст джерелаАнотація:
Guar gum grafted sodium polyacrylate have been prepared via aqueous solution graft polymerization. Furthermore, the polymers were then surface-crosslinked using trimethylolpropane triglycidyl ether (TMPTGE) to improve the properties of swollen hydrogel. Polymerization conditions were systematically optimized to achieve the optimum swelling capacity. FTIR and DSC spectra confirmed that sodium acrylate had been grafted onto guar gum chains. SEM observations showed morphology of the samples. The results confirmed that introducing guar gum into the superabsorbent could improve the swollen hydrogel mechanics performance, including hydrogel strength, resilience and dispersion, although making the water absorbency decreasing slightly. The good mechanics performance will make it feasible in hygiene application.
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Li, Yanli, Yucheng Feng, Jun Jing, and Fei Yang. "Cellulose/guar gum hydrogel microspheres as a magnetic anticancer drug carrier." BioResources 14, no. 2 (March 19, 2019): 3615–29. http://dx.doi.org/10.15376/biores.14.2.3615-3629.
Повний текст джерелаАнотація:
A novel magnetic anticancer drug carrier based on cellulose, guar gum, and Fe3O4 hydrogel microspheres was synthesized by chemical crosslinking. These microspheres were crosslinked with epoxy chloropropane and loaded with 5-fluorouracil (5-fu). The effect of the ratio of cellulose to guar gum on bead size, drug loading, and in vitro release behaviors were investigated. The influence of the magnetic content on drug loading and in vitro release behaviors were also evaluated. The magnetic hydrogel microspheres were characterized via an optical microscope, Fourier transform infrared spectroscopy, swelling behavior analysis, vibrating sample magnetometer, and ultraviolet absorption spectroscopy. The results showed that as the ratio of cellulose to guar gum increased from 3:1 to 5:1, the particle size increased from 395 to 459 um. Moreover, the drug loading capacity, encapsulation efficiency, and in vitro release behavior were influenced by the ratio of cellulose/guar gum and Fe3O4 content. Finally, the Fe3O4 particle had an adsorption effect on the drug, thereby reducing the maximum cumulative release.
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Dai, Lei, Liqiang Zhang, Baobin Wang, Bo Yang, Iqbal Khan, Avik Khan, and Yonghao Ni. "Multifunctional self-assembling hydrogel from guar gum." Chemical Engineering Journal 330 (December 2017): 1044–51. http://dx.doi.org/10.1016/j.cej.2017.08.041.
Повний текст джерела
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Gutierrez-Reyes, Jazmín E., Martín Caldera-Villalobos, Juan J. Becerra-Rodriguez, Denis A. Cabrera-Munguía, and Jesús A. Claudio-Rizo. "Hydrogels Made up of Natural Gums Based on Polysaccharides for Applications in Biomedicine: Brief Review." Asian Journal of Applied Science and Technology 06, no. 01 (2022): 152–63. http://dx.doi.org/10.38177/ajast.2022.6118.
Повний текст джерелаАнотація:
Natural gums based on polysaccharides such as guar gum, gum arabic and xanthan gum possess structure and properties that have been used for various applications in pharmaceutical, food and biomedicine. Due to their high presence of hydroxyl and/or carboxylate groups in their glycosidic skeletons, they can retain water molecules, forming matrices in the hydrogel state. These hydrogels have high biocompatibility that has been exploited in the biomedical field in strategies as controlled release of therapeutic agents, regenerative medicine, tissue engineering and modulation of cell growth. The objective of this review is to detail the chemical characteristics of natural gums and their use for the design of different hydrogel systems for applications in biomedicine.
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Pandit, Bibhas. "Biodegradable Guar Gum Based Hydrogel for Pharmaceutical Application." Current Chemical Biology 11, no. 1 (April 27, 2017): 3–9. http://dx.doi.org/10.2174/2212796811666170126125330.
Повний текст джерела
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KIM, Sumin. "GUAR GUM HYDROGEL MICROBIAL FUEL CELL USING B.MEGATERIUM." European Journal of Materials Science and Engineering 6, no. 2 (June 20, 2021): 89–98. http://dx.doi.org/10.36868/ejmse.2021.06.02.089.
Повний текст джерела
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Jussen, Daniel, Sandeep Sharma, James K. Carson, and Kim L. Pickering. "Preparation and tensile properties of guar gum hydrogel films." Polymers and Polymer Composites 28, no. 3 (August 7, 2019): 180–86. http://dx.doi.org/10.1177/0967391119867560.
Повний текст джерелаАнотація:
Guar gum hydrogels may be dried to form polymer films which have the potential for use as biodegradable alternatives to polymers such as low-density polyethylene. In this study, the tensile strength and tensile modulus of guar gel films having moisture contents ranging between 15% and 18% (wet basis) were measured at a strain rate of 1 mm min−1. Mean tensile strengths of the films ranged between 25 MPa and 40 MPa (dependent on composition) which is of similar magnitude to the tensile strength data for polyethylene and cellophane that are reported in the literature. The mean tensile modulus of the films (1.5–2.5 GPa) was higher than the tensile modulus values reported for low-density polyethylene but comparable to those for cellophane (3 GPa).
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Cunha, Pablyana L. R., Rondinelle R. Castro, Francisco A. C. Rocha, and Judith P. A. Feitosa. "Hydrogel of Guar Gum in Experimental Osteoarthritis in Rats." Macromolecular Symposia 266, no. 1 (June 2008): 48–52. http://dx.doi.org/10.1002/masy.200850609.
Повний текст джерела
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Aman, Junaid, Navin Chandra Shahi, Umesh Chandra Lohani, Divya Balodhi, Rajat Singh, Naveen Kumar, Mohd Ishfaq Bhat, and Avvaru Praveen Kumar. "Process Optimization for Development of Guar Gum-Based Biodegradable Hydrogel Film Using Response Surface Methodology." Bioinorganic Chemistry and Applications 2022 (August 16, 2022): 1–13. http://dx.doi.org/10.1155/2022/9180000.
Повний текст джерелаАнотація:
In the current study, a guar-gum-based biodegradable hydrogel film was prepared using an initiator (potassium persulfate), crosslinker (N-N methyl bis acrylamide), and plasticizer (glycerol) for packaging of fruits and vegetables. The effect of independent variables (initiator, crosslinker, and plasticizer) on the biodegradation (% wt. loss), color difference (ΔE), hardness (N), swelling index (%), and transparency (%) of the film was studied using Box–Behnken design, random surface methodology (RSM). The results showed significant effects on all the abovementioned parameters, and it was observed that the developed model was accurate, with a prediction error of only −3.19 to 2.99%. The optimized formulation for the preparation of hydrogel film was 0.15% initiator, 0.02% crosslinker, and 2.88% plasticizer exhibiting satisfactory biodegradability, color difference, hardness, swelling index, and transparency. Results showed that a guar-gum-based biodegradable hydrogel film has adequate physical, optical, and biodegradable properties and can be successfully utilized in the food packaging industry.
Дисертації з теми "GUAR GUM HYDROGEL"
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Almeida, Monique Rocha. "Desenvolvimento de um dispositivo fotoeletroqu?mico a base de g-C3N4, Cu2O e CuO para clivagem da ?gua em H2 e O2." UFVJM, 2016. http://acervo.ufvjm.edu.br/jspui/handle/1/1311.
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Universidade Federal dos Vales do Jequitinhonha e Mucuri (UFVJM)
A convers?o de energia solar em energia qu?mica usando c?lulas fotoeletroqu?micas ? uma estrat?gia interessante para armazenar energia. C?lulas fotoeletroqu?micas s?o dispositivos constitu?dos de fotoeletrodos semicondutores que absorvem luz com energia maior ou igual a energia de bandgap do semicondutor e geram cargas reativas (el?trons e buracos) na superf?cie dos fotoeletrodos capazes de promover a redu??o e oxida??o da ?gua em H2 e O2, respectivamente. Nesta disserta??o, quatro fotoeletrodos de g-C3N4, g-C3N4/Cu1%, g- C3N4/Cu5% e Cu2O/CuO foram preparados com o objetivo de desenvolver uma c?lula fotoeletroqu?mica para clivagem da ?gua em H2 e O2 de forma espont?nea. As medidas de difratometria de raios X confirmaram a presen?a das fases g-C3N4 e Cu2O/CuO nos fotoeletrodos. As imagens de MEV mostraram que os materiais ? base de g-C3N4 possuem morfologia do tipo esponja, enquanto a heterojun??o Cu2O/CuO ? formada por nanopart?culas de forma indefinida. Medidas de reflect?ncia difusa mostraram que o acoplamento do g-C3N4 e Cu2O/CuO resulta em uma melhora significativa na absor??o ?ptica dos fotoeletrodos. Medidas de ?rea espec?fica indicaram que os nanomateriais ? base de g-C3N4 tem alta ?rea superficial (?100 m2 g?1), enquanto a ?rea espec?fica da heterojun??o Cu2O/CuO foi de 17 m2 g?1. Os resultados de redu??o ? temperatura programada evidenciaram a forma??o das heterojun??es. Os testes fotoeletroqu?micos de produ??o de O2 a partir da ?gua usando luz vis?vel indicaram que em potenciais an?dicos, apenas o fotoanodo de g-C3N4 foi est?vel apresentando uma densidade de fotocorrente de 16 ?A cm?2 que corresponde a uma efici?ncia de convers?o de luz de 0,014%. Em potenciais cat?dicos, a maior densidade de fotocorrente (60 ?A cm?2) foi obtida para o fotoeletrodo Cu2O/CuO. A efici?ncia de convers?o de luz do fotocatodo de Cu2O/CuO foi de 0,029%. Com base nos dados obtidos, uma c?lula fotoeletroqu?mica p-n foi constru?da usando a heterojun??o Cu2O/CuO como fotocatodo e g- C3N4 como fotoanodo. Esta c?lula gerou uma densidade de fotocorrente in operando de 0,62 ?A cm?2 e uma fotovoltagem de 0,62 V. A efici?ncia de convers?o solar da fotoc?lula foi de 0,004% sob irradia??o de luz vis?vel. Apesar da baixa efici?ncia obtida, espera-se que esta disserta??o possa servir de inspira??o para o desenvolvimento de novos dispositivos fotoeletroqu?micos para clivagem da ?gua em H2 e O2, usando luz vis?vel.
Disserta??o (Mestrado) ? Programa de P?s-Gradua??o em Qu?mica, Universidade Federal dos Vales do Jequitinhonha e Mucuri, 2016.
The conversion of solar energy into chemical energy using photoelectrochemical cells is an interesting strategy to store energy. Photoelectrochemical cells are made up of semiconductor photoelectrodes that absorb light with energy equal or higher than the bandgap energy of the semiconductor to generate reactive charges (electrons and holes) on the surface of the photoelectrodes, which can promote the oxidation and reduction reactions of water to form H2 and O2, respectively. In this dissertation, four photoelectrodes of g-C3N4, g-C3N4/Cu1%, g- C3N4/Cu5%, and Cu2O/CuO were prepared in order to develop a photoelectrochemical cell for spontaneous water splitting into H2 and O2. The X-ray diffraction patterns confirmed the presence of g-C3N4 and Cu2O/CuO phases in the photoelectrodes. The SEM images showed that the materials based on g-C3N4 have sponge-like morphology, whereas the Cu2O/CuO heterojunction is formed by nanoparticles with undefined shapes. Diffuse reflectance measurements showed that coupling g-C3N4 and Cu2O/CuO results in a significant improvement in optical absorption of the photoelectrodes. Surface area measurements indicated that the nanomaterials based on g-C3N4 have high surface areas (?100 m2 g?1), while the specific area for the Cu2O/CuO heterojunction was 17 m2 g?1. The temperature programmed reduction results evidenced the formation of the heterojunctions. The photoelectrochemical assays of O2 production from water using visible light indicated that at anodic potentials, only the photoanode g-C3N4 was stable showing a photocurrent density of 16 ?A cm?2, which corresponds to a light conversion efficiency of 0.014%. At cathodic potentials, the higher photocurrent density (60 ?A cm?2) was obtained for the Cu2O/CuO photoelectrode. The light conversion efficiency of the Cu2O/CuO photocathode was 0.029%. Based on the obtained data, a p-n photoelectrochemical cell was constructed using the Cu2O/CuO heterojunction as the photocathode and g-C3N4 as the photoanode. This photocell generated a photocurrent density in operando of 0.62 ?A cm?2 and photovoltage of 0.62 V. The light conversion efficiency of the photocell was 0.004% under visible light irradiation. Despite the low efficiency obtained for the p-n photocell, it is expected that this dissertation may serve of inspiration for the development of new photoelectrochemical devices for water splitting into H2 and O2 using visible light.
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Melo, Edilailsa Janu?rio de. "Hematitas nanoparticuladas como fotocatalisadores potenciais para degrada??o qu?mica de contaminantes org?nicos em meio aquoso e a produ??o de hidrog?nio por fragmenta??o molecular da ?gua e da am?nia." UFVJM, 2017. http://acervo.ufvjm.edu.br/jspui/handle/1/1371.
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Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior (CAPES)
O desenvolvimento de novos semicondutores fotocatalisadores, em particular os ativos na produ??o de hidrog?nio por fragmenta??o molecular da ?gua e da am?nia (presente no lixiviado de biodigestores ou de aterros sanit?rios e em efluentes industriais), tem dominado a ordem priorit?ria de interesse nas tecnologias avan?adas para a gera??o de energia limpa. Este trabalho teve como objetivo principal avaliar a produ??o fotocatalisada de hidrog?nio gasoso, a partir da fragmenta??o molecular da ?gua ou da am?nia, por uso da hematita pura ou da hematita dopada com os c?tions met?licos cobalto, n?quel, cobre e zinco como materiais semicondutores. Os materiais preparados por coprecipita??o foram caracterizados pelas t?cnicas de EDX, MEV, DRX, espectroscopia M?ssbauer, FTIR, BET e XPS. A taxa da produ??o de hidrog?nio foi avaliada por medidas de densidade da corrente gerada pelo H2(g) evolu?do da fragmenta??o molecular da ?gua ou da am?nia, em c?lula fotoeletroqu?mica (PEC). Foram tamb?m realizados testes fotocatal?ticos, sob luz vis?vel, com as hematitas, pura e com dopantes, como fotocatalisadores para degrada??o do corante ?ndigo de carmim, utilizado como mol?cula modelo, simulando a decomposi??o de substrato org?nico poluente em ?gua presente em efluentes industriais. Os resultados dos testes de degrada??o do corante mostraram que as hematitas dopadas com cobre e zinco tiveram relativamente alta atividade na degrada??o do corante; os melhores resultados foram obtidos com a hematita com zinco. Na evolu??o do hidrog?nio da fotocat?lise da ?gua, a dopagem com c?tions met?licos n?o alterou significativamente a atividade fotoeletroqu?mica da hematita. Ainda assim, a amostra de hematita dopada com n?quel foi a que apresentou um discreto aumento da densidade de corrente, maior propor??o de hidrog?nio gasoso produzido, sob radia??o com comprimento de onda maior do que 450 nm. A densidade de corrente gerada da degrada??o da am?nia foi maior, se comparada ? fragmenta??o da ?gua. No entanto, a dopagem tamb?m n?o alterou de forma significativa a atividade PEC dos materiais. Das amostras de hematitas dopadas, a com cobre foi a que apresentou os melhores resultados fotoeletroqu?micos, ainda que abaixo da efici?ncia fotoeletroqu?mica da hematita pura.
Disserta??o (Mestrado) ? Programa de P?s-gradua??o em Biocombust?veis, Universidade Federal dos Vales do Jequitinhonha e Mucuri, 2017.
Technological developments of semiconductors to be used as photocatalysts for hydrogen production and for the degradation of organic pollutants in water in different circumstances, such as ammonia sluggishness from biodigesters and organic residues from industrial effluents, are strongly challenging the interest of the scientific community. The main objective of this work was to evaluate the molecular hydrogen production from the molecular fragmentation of water and ammonia using pure hematite and cobalt, nickel copper and zinc dopant prepared as co-precipitators as semiconductor materials. The materials prepared were characterized by EDX, MEV, XRD, M?ssbauer, FTIR, BET and XPS spectroscopy. The evaluation of the hydrogen production was carried out through measurements of current densities generated by the decomposition of water and ammonia in a photoelectrochemical cell (PEC). Photocatalytic tests were also carried out under visible light using pure hematite and with dopants as photocatalysts for the degradation of carmine indigo dye used as a model molecule. The results of the dye degradation tests showed that copper and zinc doped hematite increased dye degradation, and the best results were obtained for zinc hematite. In the evolution of hydrogen from water, the doping with metallic cations did not significantly alter photoelectrochemical activity of hematite, the hematite with nickel was the sample that presented a small increase in current density when in the presence of light. The current density generated by the ammonia degradation and consequent hydrogen production was higher when compared to water, however, doping also did not significantly alter the PEC activity of the materials, comparing the materials, the hematite with copper was the sample that presented the best results.
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Oliveira, ?ngelo Anderson Silva de. "S?ntese e caracteriza??o do l?quido i?nico tetrafluoroborato de 1-metil-3-(2,6-(S)-dimetiloct-2-eno)-imidazol como eletr?lito para produ??o de hidrog?nio via eletr?lise da ?gua." Universidade Federal do Rio Grande do Norte, 2013. http://repositorio.ufrn.br:8080/jspui/handle/123456789/12992.
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Previous issue date: 2013-11-18Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior
Ionic liquids (ILs) are organic compounds liquid at room temperature, good electrical conductors, with the potential to form as a means for electrolyte on electrolysis of water, in which the electrodes would not be subjected to such extreme conditions demanding chemistry [1]. This paper describes the synthesis, characterization and study of the feasibility of ionic liquid ionic liquid 1-methyl-3(2,6-(S)-dimethyloct-2-ene)-imidazole tetrafluoroborate (MDI-BF4) as electrolyte to produce hydrogen through electrolysis of water. The MDI-BF4 synthesized was characterized by thermal methods of analysis (Thermogravimetric Analysis - TG and Differential Scanning Calorimetry - DSC), mid-infrared spectroscopy with Fourier transform by method of attenuated total reflectance (FTIR-ATR), nuclear magnetic resonance spectroscopy of hydrogen (NMR 1H) and cyclic voltammetry (CV). Where thermal methods were used to calculate the yield of the synthesis of MDI-BF4 which was 88.84%, characterized infrared spectroscopy functional groups of the compound and the binding B-F 1053 cm-1; the NMR 1H analyzed and compared with literature data defines the structure of MDI-BF4 and the current density achieved by MDI-BF4 in the voltammogram shows that the LI can conduct electrical current indicating that the MDI-BF4 is a good electrolyte, and that their behavior does not change with the increasing concentration of water
Os l?quidos i?nicos (LIs) s?o compostos org?nicos l?quidos ? temperatura ambiente, bons condutores el?tricos, com potencial para constitu?rem como meio eletr?lito para a eletr?lise da ?gua, no qual os eletrodos n?o seriam submetidos a condi??es t?o extremas de exig?ncia qu?mica [1]. O presente trabalho descreve a s?ntese, a caracteriza??o e o estudo da viabilidade do l?quido i?nico tetrafluoroborato de 1-metil-3(2,6-(S)-dimetiloct-2-eno)-imidazol (MDI-BF4) como eletr?lito para a produ??o de hidrog?nio atrav?s da eletr?lise da ?gua. O MDI-BF4 sintetizado foi caracterizado por: m?todos t?rmicos de an?lise (An?lise Termogravim?trica - TG e Calorimetria Explorat?ria Diferencial - DSC); espectroscopia de infravermelho m?dio com transformada de Fourier pelo m?todo da reflect?ncia total atenuada (FTIR-ATR); espectroscopia de resson?ncia magn?tica nuclear de hidrog?nio (RMN 1H) e voltametria c?clica (VC). Onde os m?todos t?rmicos foram utilizadas para calcular o rendimento da s?ntese do MDI-BF4 que foi de 88,84 %; a espectroscopia de infravermelho caracterizou os grupos funcionais do composto e a liga??o B-F em 1053 cm-1; o RMN 1H analisado e comparado com dados da literatura define a estrutura do MDI-BF4 e a densidade de corrente alcan?ada pelo MDI-BF4 no voltamograma mostra que o LI consegue conduzir corrente el?trica indicando que o MDI-BF4 ? um bom eletr?lito e que seu comportamento n?o sofre altera??o com o aumento da concentra??o de ?gua
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SOLANKI, RAHUL. "PREPARATION AND ANALYSIS OF POLY (ACRYLAMIDE-GUAR GUM) HYDROGEL." Thesis, 2020. http://dspace.dtu.ac.in:8080/jspui/handle/repository/18319.
Повний текст джерелаАнотація:
As we as a whole know the significance of green science combination and portrayal of
ecological benevolent changed regular polymers is need of time. These regular polysaccharides
additionally dispose of the risk to wellbeing and condition. Guar gum is one of the significant
normally happening polymer having wide applications because of its rheological adjusting
properties in therapeutic, pharmaceutical, food, material and scores of other modern and business
divisions.
There has been wide investigation on physiochemical and pharmaceutical properties of guar gum
yet concentrate on adjusted guar gum and its subsidiaries are very inadequate. Unmodified guar
gum has certain downsides like absence of lucidity and free streaming properties, fall in
thickness and turbidity on draw out remain, and so on. These disadvantages can be overwhelmed
by altering and derivatives of guar gum and can be utilized in multidiscipline fields.
In this work I have all set hydrogels of Polyacrylamide-Guar gum hydrogels using
glutaraldehyde as cross linker and potassium persulphate as initiator. Hydrogels with varying
concentration of cross linker and guar gum were prepared and their swelling with admiration to
time and temperature were studied. The effect of concentration of cross linker and guar gum on
the inflammation of the hydrogel was calculated.
The hydrogels were described by FTIR spectroscopy and TGA. Percentage swelling was chosen
as the parameter for deciding the paramount hydrogel in each series of the guar gum
concentration.
The hydrogels showed considerable swelling and also the swelling exponent was found to be in
the range of 0.919-0.997 thus, indicating the non-fickian diffusion mechanism. The regression
coefficient was found to be 0.992-0.995.
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ALAM, GAUSH. "REMOVAL OF NICKEL FROM WASTE WATER USING GUAR GUM." Thesis, 2017. http://dspace.dtu.ac.in:8080/jspui/handle/repository/17045.
Повний текст джерелаАнотація:
Heavy metals are one of the most toxic materials to the environment. Adsorption is the
process which is used for the removal of heavy metals from wastewater. Many researches
have been conducted to remove heavy metals using different materials. Various adsorbents
have been used to remove different type of heavy metal ions from wastewater especially
those that are harmful to mankind. Activated carbons, plant or lignocellulosic wastes, clays
and biopolymers are the most common adsorbents used. For this research, Guar Gum was
used as a adsorbent to remove Heavy Metal from wastewater. Guar Gum, a type of
biopolymer, is a good adsorbent to remove the heavy metal ions from wastewater. The
synthetic wastewater was prepared in the laboratory to conduct the experiments. Batch
experiments were conducted to obtain the optimum conditions for Heavy Metals. Effect of
parameter like pH, adsorbent dose, contact time, temperature and initial metal ion
concentration were also determined. The optimum conditions obtained were 180 min contact
time, 10-500 mg adsorbent dose 1-5 g and pH 5 for Nickel. The maximum adsorption
capacity was found to be 91.9% for Nickel.
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YU, YUEH-CHIN, and 俞月琴. "Studies on Preparation and Characterization of Sodium Alginate/Guar Gum Hydrogel Beads." Thesis, 2019. http://ndltd.ncl.edu.tw/handle/6wh92c.
Повний текст джерелаАнотація:
碩士中華科技大學
健康科技研究所在職專班
107
Ferulic acid, a major active constituent of Chinese medicinal herbs, exhibits a variety of biological activities such as antioxidant, anti-inflammatory, anti-allergic, anti-cancer, and antibacterial effects. Erythromycin, a macrolide antibiotic, is commonly used in treatment of many bacterial actions. Ferulic acid-loaded and erythromycin-loaded hydrogel beads as oral delivery formulations were studied. In this work, the homogeneous sodium alginate/guar gum solution was dropped into calcium chloride solution, crosslinked by calcium ions, and the pH-sensitive hydrogel beads were formed. The swelling behaviors of sodium alginate/guar gum hydrogel beads were studied at different pH environment. The sustained release profiles of ferulic acid-loaded hydrogel beads were investigated in simulated intestinal fluid (SIF) and simulated colonic fluid (SCF). The total phenolic content and antioxidant activity of Ferulic acid-loaded hydrogel beads were evaluated using the Folin-Ciocalteau method, 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging activity and ferrous ion chelating ability assays. The MTT assays show that the sodium alginate/guar gum/ferulic acid hydrogel beads have good biocompatibility, which allow adhesion and proliferation of the L929 fibroblast cells. Finally, the antibacterial actions against gram-negative (E. coli) and gram-positive (S. aureus) bacteria of sodium alginate/guar gum/erythromycin hydrogel beads have been investigated. These results indicated that ferulic acid-loaded and erythromycin-loaded sodium alginate/guar gum hydrogel beads show a promising application in drug carriers.
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GARG, PIYUSH. "STUDIES ON HYDROGELS BASED ON POLYACRYLAMIDE AND GUAR GUM DERIVATIVES." Thesis, 2013. http://dspace.dtu.ac.in:8080/jspui/handle/repository/15677.
Повний текст джерелаАнотація:
As we all know the importance of green chemistry synthesis and characterization of environmental friendly modified natural polymers is need of time. These natural polysaccharides also eliminates the danger to health and environment. Guar gum is one of the important naturally occurring polymer having wide applications due to its rheological modifying properties in medicinal, pharmaceutical, food, textile and scores of other industrial and commercial sectors. There has been wide study on physiochemical and pharmaceutical properties of guar gum but study on modified guar gum and its derivatives are quite lacking. Unmodified guar gum has certain drawbacks like lack of clarity and free flowing properties, fall in viscosity and turbidity on prolong stay, etc. These draw backs can be overcome by modifying and derivatization of guar gum and can be used in multidiscipline fields.
In this work we are preparing blend biodegradable interpenetrating polymer networks(IPNs) hydrogels using polymers both from natural sources and synthetic ones i.e Carboxymethyl guar gum along with Polyacrylamide with varying concentrations of carboxymethyl guargum and evaluate their properties, characteristics and their potential applications in different areas of biomedical and pharmaceutical applications. Characterization of synthesized hydrogels is carried out using different characterization techniques like FTIR & SEM. Other studies such as swelling studies and their physical properties like compression strength using UTM have also been evaluated.
The blend hydrogels also exhibited the improved mechanical properties compared to those of homopolymers. The Carboxymethylated Guar Gum/Polyacrylamide blended hydrogels with the capacity of absorbing a high amount of water is also evaluated for its drug release profile at different pH. The drug used in this study was the ciprofloxacin hydrochloride. Release kinetics of ciprofloxacin hydrochloride from swollen polyacrylamide/carboxymethyl guargum cross-linked hydrogels in aqueous media have been successfully studied.
Частини книг з теми "GUAR GUM HYDROGEL"
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Khushbu, Ashank Upadhyay, and Sudhir G. Warkar. "Synthesis and Study of a Novel Carboxymethyl Guar Gum/Polyacrylate Polymeric Structured Hydrogel for Agricultural Application." In Lecture Notes in Mechanical Engineering, 1073–84. Singapore: Springer Singapore, 2021. http://dx.doi.org/10.1007/978-981-15-8542-5_95.
Повний текст джерела
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Baruah, Chinmoy, and Jayanta K. Sarmah. "Guar gum-based hydrogel and hydrogel nanocomposites for biomedical applications." In Micro- and Nanoengineered Gum-Based Biomaterials for Drug Delivery and Biomedical Applications, 473–92. Elsevier, 2022. http://dx.doi.org/10.1016/b978-0-323-90986-0.00002-9.
Повний текст джерела
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Zaki, Elsayed Gamal, Shimaa Mohamed Elsaeed, Faissal Aziz, Athir Mahmood Haddad, Aula Ali Alwattar, and Khalid Aziz. "Optimization of Green Hydrogel in Agriculture Based on Guar Gum by Response Surface Methodology." In Handbook of Research on Principles and Practices for Orchards Management, 33–50. IGI Global, 2022. http://dx.doi.org/10.4018/978-1-6684-2423-0.ch003.
Повний текст джерелаАнотація:
Water plays an essential purpose in agricultural yield. Unfortunately, water shortages have led to desertification and salination of soils, threatening the durable progress of agriculture, horticulture, and food security, especially in dried regions, where water resources are a severe problem. The hydrogel absorbed the water, released it to the plants as required while maintaining the soil moist during long periods. Biopolymer as guar gum-based hydrogel is becoming one of the most green ways to hydrogel materials for water retention. Artificial intelligence (AI) is used in hydrogel technology as a result of high energy consumption to make process control and optimization of synthesis and development. Sustainable environment for hydrogel technology was integrated by AI model.
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Das, Subhraseema, and Usharani Subuddhi. "Potential of guar gum hydrogels in drug delivery." In Plant and Algal Hydrogels for Drug Delivery and Regenerative Medicine, 143–80. Elsevier, 2021. http://dx.doi.org/10.1016/b978-0-12-821649-1.00006-4.
Повний текст джерела
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"Application of Biopolymeric Electrospun Nanofibers in Biological Science." In Materials Research Foundations, 156–201. Materials Research Forum LLC, 2021. http://dx.doi.org/10.21741/9781644901076-7.
Повний текст джерелаАнотація:
Biopolymers are those class of macromolecules which are found in nature or extracted from the living organisms. Various structures and properties of the biopolymers-based materials are well researched till to date. These mainly includes hydrogels, bio glasses, bio inks, biocomposites, fibers and others. These biopolymers-based structures have some limitations. However, Biopolymers have some common advantages (i.e., non-toxicity, easy availability, monodispersity, degradability, and better solubility etc.) and disadvantages (i.e., poor thermal and chemical stabilities, brittleness etc.). To overcome these disadvantages, it is necessary to tailor these polymers by few emerging techniques like “Electrospinning”. Electrospinning is one of the easiest techniques to prepare nanofibers from polymeric solutions by applying high voltage. Obtained nano/micro structural polymeric fibers have good properties like high surface area, porosity and low weights etc. The materials having high surface area and porosity can easily interact with cells and tissues, are better mobile vehicles for drugs, as well as possess good filtration and adsorption abilities. Thus, these one-dimensional structures of the biopolymers are very useful in various fields of biomedical especially water sanitation/desalination, tissue engineering, drug delivery and scaffolds. Various biopolymers like chitosan, chitin, sodium alginate, guar gum, polylactic acid and others are successfully fabricated as fibers and used in various fields of biomedical.
Тези доповідей конференцій з теми "GUAR GUM HYDROGEL"
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Sun, Hongyu, Liguo Zhong, Jianbin Liu, Tongchun Hao, Shihao Li, Yu Zhu, Hailong Zhang, and Kexin Wang. "Experimental Study on the Influence of Hydraulic Fracturing on Hydrogen Sulfide Generation in Longxi Block of Daqing Oilfield." In ASME 2022 41st International Conference on Ocean, Offshore and Arctic Engineering. American Society of Mechanical Engineers, 2022. http://dx.doi.org/10.1115/omae2022-79022.
Повний текст джерелаАнотація:
Abstract Hydraulic fracturing has a significant effect on increasing production and injection of oil and water wells in low-permeability and tight reservoirs. Hydrogen sulfide (H2S) was generated after hydraulic fracturing of oil and water wells in Longxi Block of Daqing Oilfield. The maximum hydrogen sulfide content in casing gas reached 232 ppm, far exceeding the safety critical concentration value (20 ppm), which increased the risk and difficulty of production and construction operation. In order to reveal the influence mechanism of fracturing on H2S generation in Daqing oilfield, the experimental simulations of the thermal decomposition of sulfur (TDS), thermochemical sulfate reduction (TSR) and bioreduction reaction of sulfate-reducing bacteria (SRB) with different compositions of fracturing fluid at different temperatures were conducted in this paper. The results showed that the influence mechanism of the fracturing fluid compositions on the formation of H2S was different when the formation temperature was different. The critical temperature of TDS and TSR reaction in the formation was 100°C and 140°C, respectively. The higher the temperature, the higher the amount of H2S was generated. The potassium persulfate (K2S2O8) and sodium sulfite (Na2SO3) in the fracturing fluid could promote the TDS and TSR reaction to generate H2S, but did not change the critical reaction temperature of TDS and TSR reaction. When the formation temperature was not higher than 56°C, the guar gum and sulfur-containing materials in the fracturing fluid could provide nutrition for SRB in the formation, which promoted the rapid reproduction of SRB in a short period of time, and then generated a large amount of H2S. The mechanism of H2S generation for fractured wells in the Longxi block with temperature of 30∼56°C was the proliferation of SRB in the fracturing fluid. The mechanism of H2S generation in fractured wells with temperature of 100∼120°C was that sulfur-containing materials promoted TSR reaction. This study clarifies the reasons and conditions for the generation of H2S, and plays an important role in the subsequent research on H2S prevention and control measures.
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Monreal, Gabriel, Frank Zamora, Hans Henrik Ovrebo, Peter Orizondo, and Otto Soidinsalo. "Characterization of a New Green Material for Offshore Well Completions and Downhole Treatments." In Offshore Technology Conference. OTC, 2022. http://dx.doi.org/10.4043/31870-ms.
Повний текст джерелаАнотація:
Abstract In oil and gas well construction during the drillouts or wellbore cleaning process, one of the most critical functions of land and offshore completions fluids is the ability to suspend solids effectively under extreme downhole conditions. Conventional agents such as xanthan gum, HEC and numerous other polymers have historically been used to accomplish this function, albeit with limitations. Functionally, these commonly used polymers depend primarily upon viscosity rather than elastic characteristics to suspend solids and require intensive chemical processing that leads to high deployment cost. Recently microfibrillated cellulose (MFC) has been investigated as a prospective suspending agent in carrier fluids for extreme downhole conditions. MFC is a unique type of superfine cellulose fibrils obtained from fully sustainable sources that have been subjected to proprietary treatment procedures, resulting in fibril bundles consisting of lateral dimensions in the sub-micron scale and lengths up to micron scale with abundant terminal hydroxyl functional groups. When dispersed into aqueous solutions, the resulting fluid has been characterized to have several favorable rheological, chemical and mechanical properties. Rheological measurements show the viscoelasticity of MFC dispersions is dominated by their storage modulus (G′ > G″) even with fluids formulated with as low as 0.25 wt% (about 20 lbm MFC /1000 gallons). The result is a suspension that exhibits superior particle suspension properties compared on a mass basis to conventional materials such as guar, CMC, HEC and xanthan gum. In addition, MFC solutions exhibit comparatively high viscosities at low shear rates but thin by several orders of magnitude at high shear, a characteristic that implies less work on surface equipment while having the ability to suspend solids at very low pump rates. MFC dispersions also have an excellent brine tolerance, demonstrating stable suspensions over weeks in fluids containing up to 150,000 mg/L TDS. The dispersions are stable at downhole relevant temperatures, applicable at low and high pH levels and resistant to shear degradation. Finally, MFC originates from natural resources and is environmentally benign and biodegradable. This paper describes the comprehensive characterization of the rheological and suspension properties that distinguish MFC from other conventionally used materials and make it fit-for-purpose as a robust, environmentally benign and high-performance suspending agent for downhole applications.