scholarly journals The development and characterization of a novel coagulant for dust suppression in open-cast coal mines

2017 ◽  
Vol 36 (1-2) ◽  
pp. 608-624 ◽  
Author(s):  
Gang Zhou ◽  
Tao Fan ◽  
Mao Xu ◽  
Han Qiu ◽  
Jiayuan Wang ◽  
...  
Keyword(s):  
Acrylic Acid ◽  
Ph Value ◽  
High Standard ◽  
Ammonium Persulfate ◽  
Cross Linking ◽  
Swelling Kinetics ◽  
Mass Ratio ◽  
Dust Suppression ◽  
The Cross ◽  
Open Cast

This paper proposes the development of a novel coagulant for dust suppression in open-cast mines. Specifically, pretreated sodium lignin sulfonate and acrylic acid were first cross-linked, then the graft copolymerization of the intermediate product (the cross-linking product) and acrylamide was conducted and finally the resulting gelatinous substances were crushed. During the reaction process, N,N’-methylene-bis-acrylamide and ammonium persulfate were used as the cross-linking agent and initiator, respectively. Subsequently, the functional groups, crystalline structure, and thermal stability of the dust coagulant were examined by means of Fourier transform infrared spectra measurements, X-ray diffraction spectra measurements, and differential scanning calorimeter analysis. Moreover, single-factor experiments were conducted to explore the optimal synthesis condition. According to the experimental results, the coagulant achieved its optimal dust suppression performance under the following conditions: the mass ratio of lignin to acrylic acid was 1:3, the mass ratio of lignin to acrylamide was 2:7, the content of the cross-linking agent was 0.9%, the mass ratio of initiator to acrylamide was 2:100, the reaction temperature was set as 60℃, and the pH value was set as 7. Finally, the coagulant was measured for its swelling kinetics, viscosity, film-forming hardness, peeling strength, and ability to suppress dust. It can be concluded that the coagulant exhibits a very high standard of both dust suppression and wind resistance.

Preparation and Characterization of Kenaf-Based Superabsorbent Polymers

2011 ◽  
Vol 183-185 ◽  
pp. 1812-1816
Author(s):  
Dan Wang ◽  
Zhan Qian Song ◽  
Shi Bin Shang ◽  
Zhan Jun Wang ◽  
Myoung Ku Lee
Keyword(s):  
Aqueous Solution ◽  
Acrylic Acid ◽  
Graft Copolymerization ◽  
Ph Value ◽  
Crosslinking Agent ◽  
Ammonium Persulfate ◽  
Deionized Water ◽  
Superabsorbent Polymers ◽  
Saline Solutions

Novel kenaf-based superabsorbent polymers (SAPs) were prepared by grafting acrylic acid (AA) and acrylamide (AM) onto kenaf cellulose. Graft copolymerization was carried out in aqueous solution using N, N’-methylenebisacrylamide (NMBA) as crosslinking agent and sodium bisulfite (NaHSO3) and ammonium persulfate ((NH4)2S2O8) as initiator. The SAPs so obtained were examined by SEM. The absorbency of SAPs consists of different kenaf cellulose in deionized water, saline solutions and different pH value solutions were investigated.

Synthesis and Properties of Thermo- and pH-Sensitive Poly[(Sodium Humate)-(N-Isopropylacrylamide)-(Acrylic Acid)] Intelligent Hydrogel

2013 ◽  
Vol 781-784 ◽  
pp. 536-541
Author(s):  
Xiao Mi Zhou ◽  
Xiao Ran Sun ◽  
Guang Yue Li
Keyword(s):  
Acrylic Acid ◽  
Suspension Polymerization ◽  
Ammonium Persulfate ◽  
Continuous Phase ◽  
Ph Sensitive ◽  
Cross Linking ◽  
Swelling Ratio ◽  
Inverse Suspension Polymerization ◽  
Sensitive Characteristics ◽  
Intelligent Hydrogel

A novel intelligent hydrogel of poly(Humic acid - Nisopropylacrylamide - Acrylic acid) (P(NIPAAm-HA-AA)) was prepared at 70°C by inverse suspension polymerization. The reactions include uses N,N-methylene-bis-acrylamide (MBA) as a cross-linking agent, ammonium persulfate (KPS) as an initiator, cyclohexane as a continuous phase and span-65 as dispersant. The influence such as concentration of monomers and cross-linking agent, mole fraction of span-65 in mixed monomers, and temperature of polymerization on the property of resulting P(NIPAAm-HA-AA) hydrogels was investigated in detail. Fourier transform infrared (FTIR) demonstrated that NIPAAm, HA and AA was synthetized successfully. The results showed that the swelling ratio (SR) of modified hydrogel was improved significantly with the dosage of NIPAAm. It was also observed that the thermosensitive and pH sensitive characteristics was strongly affected by concentrations of NIPAAm. At last, we choose NIPAAm: HA=0.3.

The Preparation of Calcium Carbonate Modified High Water-Absorbing Resin

2014 ◽  
Vol 1035 ◽  
pp. 296-302
Author(s):  
Qi Shi ◽  
Qing Luo Meng ◽  
Nong Wang
Keyword(s):  
Calcium Carbonate ◽  
Acrylic Acid ◽  
Dry Weight ◽  
High Water ◽  
Ammonium Persulfate ◽  
Sodium Acrylate ◽  
Cross Linking ◽  
Optimum Process ◽  
Process Conditions ◽  
Modified Resin

The poly (sodium acrylate/acrylic acid) water-absorbing resin was prepared by aqueous solution polymerization with acrylic acid (AA) as the monomer, calcium carbonate as the modified additives, N, N-methylene double acrylamide (NMBA) as cross-linking agent, ammonium persulfate (APS)/sodium sulfite oxidation reduction type initiator. It was found that the adsorption performance of absorbent resin modified by calcium carbonate strengthened obviously. Orthogonal and single factor experiment were used to establish the optimum parameters related to the product preparation. The best process conditions on water-absorbing properties of the modified resin was obtained. Using 150mL acrylic acid as a benchmark, the result show the optimum process conditions: the reaction temperature is 55°C, the mass fraction of monomer is 20%, the neutralization degree is 45%, modified additive dosage is 10 g, the dosage of cross-linking agent is 0.1%, and the initiator dosage is 2.0%, respectively. After made under the optimum process conditions, the water-absorbing rate of the modified resin was 676.6 times the dry weight.

scholarly journals Rapid Accessible Fabrication and Engineering of Bilayered Hydrogels: Revisiting the Cross-Linking Effect on Superabsorbent Poly(acrylic acid)

ACS Omega ◽  
2018 ◽  
Vol 3 (3) ◽  
pp. 3096-3103 ◽  
Author(s):  
Kyoung Min Lee ◽  
Hea Ji Kim ◽  
Doyoung Jung ◽  
Yuree Oh ◽  
Hyemin Lee ◽  
...  
Keyword(s):  
Acrylic Acid ◽  
Cross Linking ◽  
The Cross ◽  
Poly Acrylic Acid

scholarly journals Study of the influence of preparation parameters on sorption properties of porous collagen material

2021 ◽  
Vol 12 (2-2021) ◽  
pp. 177-179
Author(s):  
O. K. Molokanova ◽  
◽  
S. A. Shirokikh ◽  
E. S. Vainerman ◽  
M. Yu. Koroleva ◽  
...  
Keyword(s):  
Polymeric Materials ◽  
Petroleum Products ◽  
Optimal Concentration ◽  
Sorption Properties ◽  
Cross Linking ◽  
Optimal Parameters ◽  
Mass Ratio ◽  
Drying Temperature ◽  
Leather Waste ◽  
The Cross

In this work, the dependences of the sorption properties of the porous polymeric materials prepared from the cross- linked collagen on their composition and process specifications were studied. The optimal concentration of glutaraldehyde as a cross-linking agent was 0.5 wt %, the mass ratio of fish and leather waste was 1:1, and the drying temperature was 25 °C. Sorbent samples prepared using optimal parameters were effective in the sorption of petroleum products.

scholarly journals Synthesis and Characterization of Chemically Cross-Linked Acrylic Acid/Gelatin Hydrogels: Effect of pH and Composition on Swelling and Drug Release

2015 ◽  
Vol 2015 ◽  
pp. 1-15 ◽  
Author(s):  
Syed Majid Hanif Bukhari ◽  
Samiullah Khan ◽  
Muhammad Rehanullah ◽  
Nazar Mohammad Ranjha
Keyword(s):  
Acrylic Acid ◽  
Phosphate Buffer ◽  
Sol Gel ◽  
Ammonium Persulfate ◽  
Cross Linking ◽  
Release Mechanism ◽  
Ph Values ◽  
Allergy Treatment ◽  
Model Drug ◽  
Release Data

This present work was aimed at synthesizing pH-sensitive cross-linked AA/Gelatin hydrogels by free radical polymerization. Ammonium persulfate and ethylene glycol dimethacrylate (EGDMA) were used as initiator and as cross-linking agent, respectively. Different feed ratios of acrylic acid, gelatin, and EGDMA were used to investigate the effect of monomer, polymer, and degree of cross-linking on swelling and release pattern of the model drug. The swelling behavior of the hydrogel samples was studied in 0.05 M USP phosphate buffer solutions of various pH values pH 1.2, pH 5.5, pH 6.5, and pH 7.5. The prepared samples were evaluated for porosity and sol-gel fraction analysis. Pheniramine maleate used for allergy treatment was loaded as model drug in selected samples. The release study of the drug was investigated in 0.05 M USP phosphate buffer of varying pH values (1.2, 5.5, and 7.5) for 12 hrs. The release data was fitted to various kinetic models to study the release mechanism. Hydrogels were characterized by Fourier transformed infrared (FTIR) spectroscopy which confirmed formation of structure. Surface morphology of unloaded and loaded samples was studied by surface electron microscopy (SEM), which confirmed the distribution of model drug in the gel network.

pH-Sensitive Hydrogels Based on Copolymers of Chitosan with Acrylamide and Sodium Acrylate

2021 ◽  
Vol 899 ◽  
pp. 92-97
Author(s):  
Lidia Kropotova ◽  
Alexandra O. Grigoreva ◽  
A.E. Mochalova
Keyword(s):  
Ph Value ◽  
Ammonium Persulfate ◽  
Ph Sensitive ◽  
Sodium Acrylate ◽  
Cross Linking ◽  
High Moisture ◽  
Buffer Solution ◽  
Retention Capacity ◽  
Moisture Retention Capacity ◽  
Poly Acrylamide

pH-sensitive hydrogels based on chitosan-graft-poly(acrylamide-co-sodium acrylate) were synthesized via radical polymerization in solution. Ammonium persulfate was used as initiator, and various amounts of hexamine were used as a cross-linking agent. The structure of obtained hydrogels was characterized by Fourier transform infrared spectroscopy. Moisture-absorbing power of hydrogels in buffer solution with various pH value (pH = 1.65; 4.01; 12.43) was investigated. It is turned out that such a copolymers have a high moisture retention capacity (swelling index attains the value 1100%) and are capable for reusing, that makes it possible to apply the hydrogels in different areas.

Thermo- and pH-Responsive CeF3 Nanocrystals/HPC–PAA Complex Nanogel and Its Drug Release Behavior

NANO ◽  
2019 ◽  
Vol 14 (08) ◽  
pp. 1950102 ◽  
Author(s):  
Ben Liu ◽  
Qiusheng Song ◽  
Qiancheng Zhang ◽  
Haihong Ma ◽  
Ziwen Zhang ◽  
...  
Keyword(s):  
Acrylic Acid ◽  
Environmental Temperature ◽  
Ph Value ◽  
Water Solution ◽  
Drug Loading ◽  
Ammonium Persulfate ◽  
Crosslinking Reaction ◽  
Sensitive Material ◽  
Redox Initiator ◽  
Model Drug

In this study, a kind of novel rare-earth nanocrystals/hydroxypropylcellulose–poly (acrylic acid) (HPC–PAA) complex fluorescent nanogel, its responsive behavior to environmental temperature and pH value were reported. For preparation, with HPC being used as template, HPC–PAA nanogel was first synthesized by polymerization and crosslinking reaction of acrylic acid (AA) in water solution. In the process, a redox initiator, which composed of ammonium persulfate (APS) and N,N,N′,N′-tetramethylethylenediamine (TEMED), was used to initiate the reaction. Then, the as-prepared nanogel reacted with Ce(NO[Formula: see text] and NH4F solution successively, and a novel CeF3 nanocrystals/HPC–PAA complex nanogel was fabricated. The microstructure of the nanogel was characterized by Fourier transform infrared (FTIR), X-ray diffraction (XRD), Thermogravimetric (TG) and Transmission electron microscopy (TEM). The environmental sensitivity of the nanogel was investigated by photoluminescence (PL) and UV–Visible spectrophotometer (UV–Vis). The thermo- and pH-sensitive fluorescence were studied by PL at various temperatures and pH values; besides, the behavior of drug loading and release was researched by PL with a famous antibiotic of Ibuprofen as model drug. The results show that the PL intensity of the nanogel was largely affected by environmental temperature, or content of Ibuprofen loaded in the nanogel. The as-prepared nanogel can be used as useful sensitive material to detect temperature and pH value change, and drug loading or release property of Ibuprofen can be detected by PL emission of the nanogels conveniently.

Environmentally friendly polymer latex

2018 ◽  
Vol 30 (8) ◽  
pp. 927-936 ◽  
Author(s):  
Sweta Shukla ◽  
JSP Rai
Keyword(s):  
High Performance ◽  
Polymer Network ◽  
Swelling Behavior ◽  
Cross Linking ◽  
Swelling Kinetics ◽  
Polypropylene Glycol ◽  
Glycol Diacrylate ◽  
Link Density ◽  
Glass Panels ◽  
The Cross

Research in the area of coatings focuses primarily on the mechanism for the formation of film on different substrates. Because of environmental hazards related to solvent evaporation and its cost, the ambient cured waterborne systems are emerging as one of the better option for achieving superior properties in high performance applications. The properties like adhesion, gloss, hardness, water resistance, and so on may also get affected by incorporating higher acrylate in the formation of copolymers based on methyl methacrylate (MMA). The swelling behavior of any polymer network depends upon the nature of the polymer, polymer solvent compatibility, and degree of cross-linking. The swelling kinetics of emulsion polymerization of monomers MMA/butyl acrylate was studied to investigate the effect of cross-linkable monomer polypropylene glycol diacrylate (PPGDA). The prepared latex was coated on glass panels and cured at appropriate temperature. According to diffusion-controlled mechanism, the diffusion coefficient for these films varied with degree of cross-linking of the films. From the above discussed swelling behavior of different polymer films, it has been observed that PPGDA content improved the water resistivity of films. This may be due to the cross-linking nature of PPGDA molecule, which increased the cross-link density of the films.

The Role of the Initiator System in the Synthesis of Acidic Multifunctional Nanoparticles Designed for Molecular Imprinting of Proteins

2020 ◽  
Vol 65 (1) ◽  
pp. 28-41
Author(s):  
Marwa Aly Ahmed ◽  
Júlia Erdőssy ◽  
Viola Horváth
Keyword(s):  
Acrylic Acid ◽  
Binding Affinity ◽  
Molecular Imprinting ◽  
Low Temperatures ◽  
Ammonium Persulfate ◽  
Sodium Bisulfite ◽  
Multifunctional Nanoparticles ◽  
High Affinity ◽  
Initiator System

Multifunctional nanoparticles have been shown earlier to bind certain proteins with high affinity and the binding affinity could be enhanced by molecular imprinting of the target protein. In this work different initiator systems were used and compared during the synthesis of poly (N-isopropylacrylamide-co-acrylic acid-co-N-tert-butylacrylamide) nanoparticles with respect to their future applicability in molecular imprinting of lysozyme. The decomposition of ammonium persulfate initiator was initiated either thermally at 60 °C or by using redox activators, namely tetramethylethylenediamine or sodium bisulfite at low temperatures. Morphology differences in the resulting nanoparticles have been revealed using scanning electron microscopy and dynamic light scattering. During polymerization the conversion of each monomer was followed in time. Striking differences were demonstrated in the incorporation rate of acrylic acid between the tetramethylethylenediamine catalyzed initiation and the other systems. This led to a completely different nanoparticle microstructure the consequence of which was the distinctly lower lysozyme binding affinity. On the contrary, the use of sodium bisulfite activation resulted in similar nanoparticle structural homogeneity and protein binding affinity as the thermal initiation.

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