scholarly journals Effective Enhancement of Water Absorbency of Itaconic Acid Based-Superabsorbent Polymer via Tunable Surface—Crosslinking

Polymers ◽  
2021 ◽  
Vol 13 (16) ◽  
pp. 2782
Author(s):  
Yong-Rok Kwon ◽  
Jung-Soo Kim ◽  
Dong-Hyun Kim
Keyword(s):  
Itaconic Acid ◽  
Photoelectron Spectroscopy ◽  
Crosslinking Agent ◽  
Absorption Capacity ◽  
Gel Strength ◽  
Superabsorbent Polymer ◽  
Optimal Conditions ◽  
Retention Capacity ◽  
X Ray ◽  
Crosslinking Reactions

A superabsorbent polymer (SAP) was synthesized by copolymerizing itaconic acid and vinyl sulfonic acid. The typically low absorbency of itaconic acid-based SAPs under mechanical loads was improved by introducing surface crosslinking. Fourier-transform infrared spectroscopy and X-ray photoelectron spectroscopy were used to characterize the synthesis and surface-crosslinking reactions in the SAP. Various conditions for surface-crosslinking reactions, such as the surface-crosslinking solution, content of surface-crosslinking agent, and reaction temperature, were explored and correlated with the gel strength and absorption characteristics of the resulting SAP particles. The distilled water content in the surface-crosslinking solution strongly influenced the absorption capacity of the SAP, but this sensitivity decreased when acetone was used as a co-solvent. Itaconic acid-based SAP that was crosslinked under optimal conditions exhibited centrifuge retention capacity and absorbency under a load of 31.1 and 20.2, respectively.

A Two-step Electrodeposition of Pd-Cu/Cu2O Nanocomposite on FTO Substrate for Non-enzymatic Hydrogen Peroxide Sensor

2021 ◽  
Vol 17 ◽  
Author(s):  
Ke Huan ◽  
Li Tang ◽  
Dongmei Deng ◽  
Huan Wang ◽  
Xiaojing Si ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Cyclic Voltammetry ◽  
Photoelectron Spectroscopy ◽  
Chemical Structure ◽  
Pd Nanoparticles ◽  
Optimal Conditions ◽  
Potential Oscillation ◽  
X Ray Diffraction ◽  
X Ray

Background: Hydrogen peroxide (H2O2) is a common reagent in the production and living, but excessive H2O2 may enhance the danger to the human body. Consequently, it is very important to develop economical, fast and accurate techniques for detecting H2O2. Methods: A simple two-step electrodeposition process was applied to synthesize Pd-Cu/Cu2O nanocomposite for non-enzymatic H2O2 sensor. Cu/Cu2O nanomaterial was firstly electrodeposited on FTO by potential oscillation technique, and then Pd nanoparticles were electrodeposited on Cu/Cu2O nanomaterial by cyclic voltammetry. The chemical structure, component, and morphology of the synthesized Pd-Cu/Cu2O nanocomposite were characterized by X-ray diffraction, scanning electron microscopy and X-ray photoelectron spectroscopy. The electrochemical properties of Pd-Cu/Cu2O nanocomposite were studied by cyclic voltammetry and amperometry. Results: Under optimal conditions, the as-fabricated sensor displayed a broad linear range (5-4000 µM) and low detection limit (1.8 µM) for the determination of H2O2. The proposed sensor showed good selectivity and reproducibility. Meanwhile, the proposed sensor has been successfully applied to detect H2O2 in milk. Conclusion: The Pd-Cu/Cu2O/FTO biosensor exhibits excellent electrochemical activity for H2O2 reduction, which has great potential application in the field of food safety.

High Resolution X-Ray Photoelectron Spectroscopy Study of the Interaction of Copper Ion with Chitosan Thin Film

2015 ◽  
Vol 1087 ◽  
pp. 241-245 ◽  
Author(s):  
Wing Fen Yap ◽  
W. Mahmood Mat Yunus ◽  
Zainal Abdib Talib ◽  
Yusof Nor Azah
Keyword(s):  
Thin Film ◽  
High Resolution ◽  
Photoelectron Spectroscopy ◽  
Chemical Interaction ◽  
Crosslinking Agent ◽  
Copper Ion ◽  
Aqueous Acetic Acid ◽  
X Ray ◽  
Glass Cover Slip ◽  
Crosslinked Chitosan

In this study, high-resolution X-ray photoelectron spectroscopy (XPS) has been used to study the chemical interaction between copper ion and chitosan thin film. The chitosan solution was synthesized by homogeneous reaction of medium molecular weight chitosan in aqueous acetic acid with glutaraldehyde as crosslinking agent. Then the solution was deposited on glass cover slip by spin coater to form a thin film. The functional group and chemical binding of crosslinked chitosan thin film has been confirmed by XPS. XPS revealed that copper ion adsorbed to the crosslinked chitosan thin film and the functional groups involved in the adsorption mechanisms of copper ion on the thin film were determined.

scholarly journals Enhanced Photocatalytic Activity of Titania by Co-Doping with Mo and W

Catalysts ◽  
2018 ◽  
Vol 8 (12) ◽  
pp. 631 ◽  
Author(s):  
Osmín Avilés-García ◽  
Jaime Espino-Valencia ◽  
Rubí Romero-Romero ◽  
José Rico-Cerda ◽  
Manuel Arroyo-Albiter ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
Diffuse Reflectance Spectroscopy ◽  
High Surface ◽  
High Surface Area ◽  
Absorption Capacity ◽  
Radiation Absorption ◽  
Experimental Conditions ◽  
X Ray ◽  
Assembly Method ◽  
Co Doped

Various W and Mo co-doped titanium dioxide (TiO2) materials were obtained through the EISA (Evaporation-Induced Self-Assembly) method and then tested as photocatalysts in the degradation of 4-chlorophenol. The synthesized materials were characterized by thermogravimetric analysis (TGA), Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), Raman spectroscopy (RS), N2 physisorption, UV-vis diffuse reflectance spectroscopy (DRS), X-ray photoelectron spectroscopy (XPS), and transmission electron microscopy (TEM). The results showed that the W-Mo-TiO2 catalysts have a high surface area of about 191 m2/g, and the presence of an anatase crystalline phase. The co-doped materials exhibited smaller crystallite sizes than those with one dopant, since the crystallinity is inhibited by the presence of both species. In addition, tungsten and molybdenum dopants are distributed and are incorporated into the anatase structure of TiO2, due to changes in red parameters and lattice expansion. Under our experimental conditions, the co-doped TiO2 catalyst presented 46% more 4-chlorophenol degradation than Degussa P25. The incorporation of two dopant cations in titania improved its photocatalytic performance, which was attributed to a cooperative effect by decreasing the recombination of photogenerated charges, high radiation absorption capacity, high surface areas, and low crystallinity. When TiO2 is co-doped with the same amount of both cations (1 wt.%), the highest degradation and mineralization (97% and 74%, respectively) is achieved. Quinones were the main intermediates in the 4-chlorophenol oxidation by W-Mo-TiO2 and 1,2,4-benzenetriol was incompletely degraded.

Fabrication of Nickel Sulfide/Nitrogen-Doped Reduced Graphene Oxide Nanocomposite as Anode Material for Lithium-Ion Batteries and Its Electrochemical Performance

2020 ◽  
Vol 20 (11) ◽  
pp. 6782-6787
Author(s):  
Yeon-Ju Lee ◽  
Tae-Hyun Ha ◽  
Gyu-Bong Cho ◽  
Ki-Won Kim ◽  
Jou-Hyeon Ahn ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Reduced Graphene Oxide ◽  
Photoelectron Spectroscopy ◽  
Lithium Ion ◽  
Treatment Method ◽  
Retention Capacity ◽  
Graphene Nanocomposites ◽  
X Ray ◽  
Nitrogen Doped ◽  
Reduced Graphene

In this study, NiS/graphene nanocomposites were synthesized by simple heat treatment method of three graphene materials (graphene oxide (GO), reduced graphene oxide (rGO) and nitrogen-doped graphene oxide (N-rGO)) and NiS precursor. The morphology and crystal structure of NiS/graphene nanocomposites were characterized using field emission scanning electron microscope (FE-SEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and Raman spectroscopy. Electrochemical properties were also investigated. NiS/graphene nanocomposites homogeneously wrapped by graphene materials have been successfully manufactured. Among the three nanocomposites, NiS/N-rGO nanocomposite exhibited the highest initial and retention capacity in discharge, respectively, of 1240 mAh/g and 467 mAh/g up to 100 cycles at 0.5 C.

Electrochemical Sensor Based on Electrospun Three-Dimensional Carbon Nanofibers to Determine Trace Levels of Cu(II)

2020 ◽  
Vol 12 (5) ◽  
pp. 693-700 ◽  
Author(s):  
Hao Cheng ◽  
Zhengyuan Zhou ◽  
Danfeng Qin ◽  
Wenyi Huang ◽  
Jun Feng ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
Hydrofluoric Acid ◽  
Carbon Nanofiber ◽  
Tap Water ◽  
Three Dimensional ◽  
Differential Pulse ◽  
Mixed Solution ◽  
Optimal Conditions ◽  
X Ray ◽  
Pulse Voltammetry

In this study, a three-dimensional carbon nanofiber network was formed by first electrospinning a mixed solution of montmorillonite (MMT) and polyacrylonitrile (PAN), and then carbonizing the composite nanofiber and etching it with hydrofluoric acid. The form and morphology of the nanofibers were analysized by scanning electron microscopy (SEM), Raman microspectroscopy (Raman), and X-ray photoelectron spectroscopy (XPS). The sensor fabricated on three-dimensional carbon nanofiber showed a good linear response (y = 0.076x – 0.110, R2 = 0.999, and y = 0.193x – 1.770, R2 = 0.998), high stability and selectivity, and a low detection limit (0.4 μg · L–1) for Cu(II) as measured using differential pulse voltammetry under the optimal conditions, and the method mentioned above was also used to analyze Cu(II) in real tap water samples, which had good recoveries.

scholarly journals A Novel Superabsorbent Polymer from Crosslinked Carboxymethyl Tragacanth Gum with Glutaraldehyde: Synthesis, Characterization, and Swelling Properties

2021 ◽  
Vol 2021 ◽  
pp. 1-14
Author(s):  
Yahya Bachra ◽  
Ayoub Grouli ◽  
Fouad Damiri ◽  
Mohammed Talbi ◽  
Mohammed Berrada
Keyword(s):  
Negative Impact ◽  
Tap Water ◽  
Crosslinking Agent ◽  
Absorption Capacity ◽  
Retention Capacity ◽  
Swelling Properties ◽  
Global Environmental Problems ◽  
Tragacanth Gum ◽  
Global Environmental ◽  
New Material

Nowadays, current global environmental problems include measures to eliminate or reduce the negative impact of chemicals from petroleum sources and, therefore, the use of materials from natural resources is increasingly recommended. In this context, natural-based superabsorbent polymers derived from polypeptides and polysaccharides have undergone chemical and biochemical modifications to improve their ability to absorb and retain large amounts of liquids. In the present paper, a new process has been used to overcome the side effects of radical polymerization in the manufacture of conventional polyacrylate superabsorbents (SAPs). Tragacanth gum (TG) was selected to prepare a new superabsorbent material (CMTG-GA) based on carboxymethyl tragacanth (CMTG) crosslinked with glutaraldehyde (GA). The characterization of the polymer was carried out by FTIR, TGA, XRD, and SEM. The effect of the amount of crosslinking agent and the pH on the water absorption capacity was also examined. Subsequently, swelling studies were performed using free swelling capacity (FSC) and centrifuge retention capacity (CRC) techniques in distilled water, tap water, and saline solution. The results showed that the CRC of the new material is not less than 42.1 g/g, which was observed for a ratio of 20% by weight of GA to CMTG. Likewise, the maximum absorption results were 43.9 and 32.14 g/g, respectively, for FSC and CRC at pH 8.0. In addition, a comparison of the swelling capacities of the synthesized product with a commercial SAP extracted from a baby diaper, well known in the Moroccan market, showed that the performances were very similar.

scholarly journals Investigations on the Electrochemical Atomic Layer Growth of Bi2Se3 and the Surface Limited Deposition of Bismuth at the Silver Electrode

Materials ◽  
2018 ◽  
Vol 11 (8) ◽  
pp. 1426 ◽  
Author(s):  
Walter Giurlani ◽  
Andrea Giaccherini ◽  
Nicola Calisi ◽  
Giovanni Zangari ◽  
Emanuele Salvietti ◽  
...  
Keyword(s):  
Atomic Layer Deposition ◽  
Ultrathin Films ◽  
Photoelectron Spectroscopy ◽  
Atomic Layer ◽  
Layer Growth ◽  
Electrochemical Studies ◽  
Optimal Conditions ◽  
X Ray ◽  
Layer Deposition ◽  
Controlled Deposition

The Electrochemical Atomic Layer Deposition (E-ALD) technique is used for the deposition of ultrathin films of bismuth (Bi) compounds. Exploiting the E-ALD, it was possible to obtain highly controlled nanostructured depositions as needed, for the application of these materials for novel electronics (topological insulators), thermoelectrics and opto-electronics applications. Electrochemical studies have been conducted to determine the Underpotential Deposition (UPD) of Bi on selenium (Se) to obtain the Bi2Se3 compound on the Ag (111) electrode. Verifying the composition with X-ray Photoelectron Spectroscopy (XPS) showed that, after the first monolayer, the deposition of Se stopped. Thicker deposits were synthesized exploiting a time-controlled deposition of massive Se. We then investigated the optimal conditions to deposit a single monolayer of metallic Bi directly on the Ag.

Itaconic acid‐based superabsorbent polymer with high gel strength and biocompatibility

2022 ◽  
Author(s):  
Yong Rok Kwon ◽  
Hae Chan Kim ◽  
Jung Soo Kim ◽  
Young‐Wook Chang ◽  
Hansoo Park ◽  
...  
Keyword(s):  
Itaconic Acid ◽  
Gel Strength ◽  
Superabsorbent Polymer

scholarly journals Antibacterial Superabsorbent Polymers from Tara Gum Grafted Poly(Acrylic acid) Embedded Silver Particles

Polymers ◽  
2018 ◽  
Vol 10 (9) ◽  
pp. 945 ◽  
Author(s):  
Mingfang Chi ◽  
Chang Liu ◽  
Jie Shen ◽  
Zhehai Dong ◽  
Zi Yang ◽  
...  
Keyword(s):  
Electron Microscope ◽  
Acrylic Acid ◽  
Photoelectron Spectroscopy ◽  
Silver Ions ◽  
Absorption Capacity ◽  
Superabsorbent Polymers ◽  
X Ray ◽  
Amorphous Nanoparticles ◽  
Silver Composite ◽  
Poly Acrylic Acid

Tara gum/silver composite superabsorbent polymers were synthesized with tara gum grafted poly(acrylic acid), using K2S2O8 (KPS) as an initiator and N,N′-methylenebisacrylamide (MBA) as a cross-linker. The products were characterized by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), transmission electron microscope (TEM), scanning electron microscope (SEM) and X-ray photoelectron spectroscopy (XPS). The results showed that the silver ions were partially reduced to Ag0 and the amorphous nanoparticles containing Ag0 and Ag2O were around 10~50 nm in size The tara gum/silver composite superabsorbent polymers exhibited an interconnected porous structure with strong water absorption capacity. The swelling ratio of each product could reach 473 g/g in distilled water and 62 g/g in 0.9% NaCl solution. The antimicrobial activity of the samples against Staphylococcus aureus and Escherichia coli increased with the addition of AgNO3 from 0 to 125 mg. This work indicates that the developed tara gum/silver composite superabsorbent polymers can be potentially used for biomedical applications.

scholarly journals Enhancement of Gel Strength of Itaconic Acid-Based Superabsorbent Polymer Composites Using Oxidized Starch

Polymers ◽  
2021 ◽  
Vol 13 (17) ◽  
pp. 2859
Author(s):  
Haechan Kim ◽  
Jungsoo Kim ◽  
Donghyun Kim
Keyword(s):  
Ethylene Glycol ◽  
Ammonium Persulfate ◽  
Diglycidyl Ether ◽  
Gel Strength ◽  
Superabsorbent Polymer ◽  
Retention Capacity ◽  
Oxidized Starch ◽  
Crosslinking Process ◽  
Poly Ethylene ◽  
Disposable Diapers

Herein, core-superabsorbent polymer (CSAP) composites are prepared from oxidized starch (OS) via aqueous solution copolymerization using ammonium persulfate as the initiator, and 1,6-hexanediol diacrylate as the inner-crosslinker. The surface-crosslinking process is performed using various surface-crosslinkers, including bisphenol A diglycidyl ether (BADGE), poly(ethylene glycol) diglycidyl ether (PEGDGE), ethylene glycol diglycidyl ether (EGDGE), and diglycidyl ether (DGE). The structures of the CSAP composites and their surface-crosslinked SAPs (SSAPs) are characterized using Fourier transform infrared (FT-IR) spectroscopy, their absorption properties are measured via centrifuge retention capacity (CRC), absorbency under load (AUL), permeability, and re-swellability tests, and their gel strengths according to surface-crosslinker type and EGDGE content are examined via rheological analysis. The results indicate that an EGDGE content of 0.75 mol provides the optimum surface-crosslinking and SSAP performance, with a CRC of 34.8 g/g, an AUL of 27.2 g/g, and a permeability of 43 s. The surface-crosslinking of the CSAP composites using OS is shown to improve the gel strength, thus enabling the SAP to be used in disposable diapers.

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