Papers by Keyword: Polyacrylamide

Abstract: Zinc-ion batteries have attracted significant attention due to their low cost, rechargeability, and superior safety features. In fact, the use of aqueous electrolytes negatively affects battery performance due to the solid electrolyte interface (SEI), creating zinc corrosion, hydrogen evolution reaction (HER), and dendrite formation. To address these challenges, quasi-solid electrolytes (QSE) based on polyacrylamide-poly (3-(1-vinyl-3-imidazolio) propanesulfonate) (PAM/PVIPS) have been developed. PAM stands out as matrix QSE due to its excellent flexibility and electrochemical stability. PVIPS offers a well-defined pathway for ion transportation caused by cationic and anionic groups in structure. Clearly, the asymmetrical zinc cell with PAM/PVIPS QSE effectively reduces the overpotential profile, prolongs the stabilized zinc plating/stripping and enhances ionic conductivity, compared to PAM QSE. Additionality, the performance of Zn||δ-MnO₂ is also enhanced with PAM/PVIPS QSE, yielding the specific capacity value of 65 mAh g^-1, which is superior to the pristine PAM QSE (56 mAh g^-1).

Abstract: Flexible and wearable electronics are increasingly popular and utilized in various forms. Batteries have become essential as an energy source for wearable electronics. To meet demands of such electronics, these batteries must remain flexible, lightweight, possess good electrochemical performance, customizable shape, and ensure safety. Zinc-ion batteries (ZIBs) have emerged as a promising energy source for these applications. However, ZIBs encounter challenges due to the lack of flexible electrolytes. Polyacrylamide (PAM) is a polymer widely used as gel polymer electrolytes (GPEs) owing to its versatile electrical conductivity and excellent flexibility. However, PAM alone lacks the mechanical strength required to support flexible and wearable electronics adequately. To address this limitation, alginate (Alg), a polysaccharide with good compatibility with PAM, is incorporated in varying concentrations (0-3 %wt.) to form interpenetrating networks (IPN) hydrogels, with a chemical network of PAM and a physical network of alginate to enhance the overall mechanical properties. Following this, the 3D-printed PAM/Alg hydrogels are immerged in a 2M ZnSO₄ electrolyte to create PAM/Alg gel polymer electrolytes (PAM/Alg-GPEs). This process significantly improves the mechanical properties of PAM/Alg-GPEs. Subsequently, the ionic conductivity of these 3D-printed PAM/Alg-GPEs is evaluated using electrochemical impedance spectroscopy (EIS). The results demonstrate that PAM/Alg-GPEs exhibit the desired flexibility along with sufficient electrochemical performance, making them promising candidates for use as wearable electrolytes in zinc-ion batteries.

Abstract: The granulometric composition of the metal/scale suspensions formed at electroerosive machining (EEM) of metal items made of the ST-10 steel has been determined to evaluate the need for a flocculant for the suspension particles extraction and decontamination of the machining working fluid. Even though most suspension particles are large enough and quickly self-precipitate, some particles are too small (sized 6 µm or less) and form quite stable suspensions, requiring additional flocculants to be extracted. Pure polyacrylamide with a molecular weight of 4-5*10⁶ atomic units and an anionic polymer flocculant BESFLOC-4041 were considered as decontamination agents for the metal/scale suspensions. It was found that the latter agent is more effective, and it ensures the effective decontamination of an EEM working fluid. An admixture of 0.05 g/L of BESFLOC-4041 ensures effective clarification (with the decontamination efficiency of 90-95 %) of the metal/scale suspension with a dispersed phase concentration of up to 1.0 g/L. The flocculation efficiency of polyacrylamimde is lower (67-85 %) and its best performance is achieved at the concentration of 0.08 g/L.

Abstract: Enhanced Oil Recovery (EOR) is a promising technology for increasing crude oil production, especially from old wells. Polymer flooding is one of the techniques used in EOR in which the water-soluble polymer is added to increase the viscosity of the injected fluid. However, this technique has not been implemented in Indonesia due to the unavailability of locally-synthesized polymers. Therefore, this research aims to synthesize polyacrylamides and their partially-hydrolyzed derivatives and to study the possibility of their utilization for the EOR application. Various polymerization conditions using potassium persulfate (KPS) as initiators have been realized and the resulting polymers were characterized using FTIR spectroscopy and rheology measurement. It was found that higher monomer concentration resulted in higher viscosity-average molecular weight of polyacrylamide. Further study revealed that the hydrolysis of polyacrylamide by alkaline solution significantly increased the viscosity of 1000 ppm solution from 1.5 to 145.40 cP at room temperature, which is comparable to one of the commercial products. These results showed that the simple synthesis and hydrolysis method could be effectively used to produce water-soluble polymers for the EOR application.

Abstract: The main attention is paid to the study of processing mechanisms the surface of the electrode affects the kinetics of the electrodeposition of metals from various solutions of their complex salts, as well as improving the technology of obtaining electrolytic powder. Special attention was paid to the detailed study of regularities of the processes occurring during the electrodeposition of copper. Discussed features of the processes of separation of copper powders from solutions of ammonium chloride with addition of complexing polymers of polyacrylamide and polyvinylpyrrolidone's. The basic laws of surface treatment are considered cathode and processes affecting the kinetics of electrodeposition of metals various factors on the particle growth rate and purity of the resulting powders. Researches on improvement of technology of receiving and the intensification of the processes of electrodeposition of copper powders from complex electrolytes'.

Abstract: Crude turmeric extract (CTE), which is a natural substance, is obtained from Curcuma Longa L. This substance is widely used in pharmaceutical application because of its ability to treat various diseases. Dermatitis is one of the many diseases that can be treated by CTE due to their inhibition of gram-negative and gram-positive bacteria. CTE has short half-life and easy to degradation. Therefore, protection has to be applied on CTE to prevent from decomposition before applying to skin. This research mainly focuses on preparation of CTE loaded poly (acrylamide-co-acrylic acid) (PAMAA) hydrogel microspheres (HM) at 9:1, 8:2 and 7:3 mole ratios and investigation of the releasing profile of CTE from microsphere. The particle size distribution of PAMAA microsphere that is analyzed by SEM found that mole ratios of PAMAA with 9:1, 8:2 and 7:3 showed the narrow particle distribution with average particle size at 28.1±7.4, 25.5±6.6 and 23.2±5.5 respectively. Thermal decomposition property of PAMAA is confirmed by TGA and HM swelling ratios are confirmed by weight indicated that the percentage swelling ratios of PAMAA with 9:1, 8:2 and 7:3 mole ratios is 1500, 1230 and 780 respectively. CTE releasing profiles are confirmed by UV-Vis in the media solutions of PBS pH 8.5 and NaOH pH 12.

Abstract: Polyacrylamide/polypyrrole (PAM/PPy) hydrogel was developed for the application in controlled drug delivery. PAM/PPy hydrogel was synthesized via free-radical polymerization of acrylamide using ammonium persulfate (APS) as initiator in the dispersion of PPy nanoparticle. N,N’-methylenebisacrylamide (MBA) and N,N,N’,N’-tetra-methylenediamine (TEMED) were utilized as cross-linker and accelerator, respectively. Salicylic acid (SA) was selected as a model drug in this work. The effect of PPy contents on SA-loading and releasing performances was investigated. The more PPy content was incorporated, the greater SA-loading and releasing were found. This is attributed to the increasing pore size of the PAM hydrogel when PPy nanoparticles were incorporated. Drug releasing performance from the SA-loaded PAM/PPy hydrogel were controllable under the applied potential of 1.0 volt. The research exhibits the potential of using conductive polymer hydrogel to control the drug release rate at an optimal desired level.

Abstract: This paper reviews water swelling of rubber, based on nitrile-butadiene rubber, modified by polyacrylamide and copolymer acrylamide with potassium acrylate, also their combination with sodium-carboxymethyl cellulose. During the exposure for 14 days at a temperature of 67 °С swelling ratio in water is 200 % and 47 % in 10 % aqueous solution of sodium chloride.

Abstract: In many cases, acetic acid is categorized as hazardous to health. A high-performance sensor for detecting acetic acid is urgently required. This study aims to observe the characteristics of quartz crystal microbalance (QCM) coated with polyacrylamide as an acetic acid sensor. For this purpose, we prepared the sensor by firstly coating with 1-dodecanethiol (using self-assembled-monolayers or SAM technique) followed subsequently by glutaraldehyde and polyacrylamide (PAM).As results, the sensors showed less sensitivity to humidity changes, which is one of the basic prerequisites for a stable sensor to an environment. We also obtained that the sensor showed relatively fast response time and high sensitivity to acetic acid vapor of about 96 seconds and 12.9 Hz/(mgL^-1), respectively. Further research, however, is still required to improve the sensitivity and specificity by choosing more selective polymers.

Abstract: This paper describes the results of studies on the synthesis and functionalization of the surface of nanoscale and ultradispersed copper powders in the production process. The principles of deagglomeration and specific problems for Nanoparticles are considered. The paper presents data on stabilization of copper nanoparticles in the process of obtaining, highlights the problems that require a good understanding, namely the study of the behavior of different types of ultra and nanoscale copper powders in the processes related to production of polymeric composite materials.