Жарияланымдар / Публикации

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Synthesis and Heavy-Metal Sorption Studies of N,N-Dimethylacrylamide-Based Hydrogels
(Multidisciplinary Digital Publishing Institute, 2021-09-13)
Ayatzhan Akhmetzhan
;
Nurgeldi Abeu
;
Sotirios Nik. Longinos
;
A. K. Tashenov
;
Nurbala Myrzakhmetova
In this work, a hydrogel system was produced via radical polymerization of N,N-dimethylacrylamide and 2-acrylamido-2-methylpropanesulfonic acid in the presence of N,N-methylene-bis-acrylamide as a crosslinker and ammonium persulfate as an initiator. Parameters that impact the conversion of copolymerization (such as initial concentration of monomers, temperature, initiator dose, and time) were studied. The swelling degree of the hydrogel was investigated with the addition of a crosslinker and initiator at different pH levels. A hydrogel with high conversion and high swelling degree was selected to investigate their ability for adsorption of Pb(II) ions from solutions. Adsorption behavior of Pb(II) ions in a hydrogel was examined as a function of reaction time and concentration of lead ions from a solution of Pb(II) ions.
Цитирования (OpenAlex) 24Цитирования (OpenCitations) 19
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A Short Review on the N,N-Dimethylacrylamide-Based Hydrogels
(Multidisciplinary Digital Publishing Institute, 2021-11-26)
Ayatzhan Akhmetzhan
;
Nurbala Myrzakhmetova
;
Nurgul Amangeldi
;
Zhanar Kuanyshova
;
Nazgul Akimbayeva
Scientists have been encouraged to find different methods for removing harmful heavy metal ions and dyes from bodies of water. The adsorption technique offers promising outcomes for heavy metal ion removal and is simple to run on a large scale, making it appropriate for practical applications. Many adsorbent hydrogels have been developed and reported, comprising N,N-dimethylacrylamide (DMAA)-based hydrogels, which have attracted a lot of interest due to their reusability, simplicity of synthesis, and processing. DMAA hydrogels are also a suitable choice for self-healing materials and materials with good mechanical properties. This review work discusses the recent studies of DMAA-based hydrogels such as hydrogels for dye removal and the removal of hazardous heavy metal ions from water. Furthermore, there are also references about their conduct for self-healing materials and for enhancing mechanical properties.
Цитирования (OpenAlex) 45Цитирования (OpenCitations) 38
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Kinetic Analysis of Methane Hydrate Formation with Butterfly Turbine Impellers
(Multidisciplinary Digital Publishing Institute, 2022-07-08)
Sotirios Nik. Longinos
;
Dionisia Dimitra Longinou
;
Nurbala Myrzakhmetova
;
Nazgul Akimbayeva
;
M. B. Zhursumbaeva
Heat generation during gas hydrate formation is an important problem because it reduces the amount of water and gas that become gas hydrates. In this research work, we present a new design of an impeller to be used for hydrate formation and to overcome this concern by following the hydrodynamic literature. CH4 hydrate formation experiments were performed in a 5.7 L continuously stirred tank reactor using a butterfly turbine (BT) impeller with no baffle (NB), full baffle (FB), half baffle (HB), and surface baffle (SB) under mixed flow conditions. Four experiments were conducted separately using single and dual impellers. In addition to the estimated induction time, the rate of hydrate formation, hydrate productivity and hydrate formation rate, constant for a maximum of 3 h, were calculated. The induction time was less for both single and dual-impeller experiments that used full baffle for less than 3 min and more than 1 h for all other experiments. In an experiment with a single impeller, a surface baffle yielded higher hydrate growth with a value of 42 × 10−8 mol/s, while in an experiment with dual impellers, a half baffle generated higher hydrate growth with a value of 28.8 × 10−8 mol/s. Both single and dual impellers achieved the highest values for the hydrate formation rates that were constant in the full-baffle experiments.
Цитирования (OpenAlex) 6Цитирования (OpenCitations) 7
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Superhydrophobic SiO2/Trimethylchlorosilane Coating for Self-Cleaning Application of Construction Materials
(Multidisciplinary Digital Publishing Institute, 2022-09-28)
Aliya Kurbanova
;
Nurbala Myrzakhmetova
;
Nazgul Akimbayeva
;
K. O. Kishibayev
;
Marzhan Nurbekova
This study has demonstrated, for the first time, the potential application of coatings to protect bricks or architectures against detrimental atmospheric effects via a self-cleaning approach. In this research, a facile fabrication method was developed to produce amorphous SiO2 particles and their hierarchical structures via applying trimethylchlorosilane (TMCS). They were fully characterized by various surface analytic tools, including a goniometer, SEM, AFM, zeta sizer, and a spectroscopic technique (FTIR), and then applied as super hydrophobic coatings on glass and sand. The characterization results revealed that the SiO2 particles are amorphous, quasi-spherical particles with an average diameter of 250–300 nm, and the hierarchical structures in the film were assembled from building blocks of SiO2 and TMCS. The wettability of the films can be controlled by changing the pH of the SiO2/TCMS dispersion. A super hydrophobic surface with a water contact angle of 165° ± 1° was achieved at the isoelectric point of the films. The obtained translucent super hydrophobic SiO2/TMCS coatings show good self-cleaning performances for glass and sand as construction materials. This study indicated that the superhydrophobic coatings may have potential applications in the protection of buildings and construction architectures in the future.
Цитирования (OpenAlex) 40Цитирования (OpenCitations) 31
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Public health risks associated with antibiotic residues in poultry food products
(Elsevier BV, 2025-03-16)
Sylvester Chibueze Izah
;
Akmaral Nurmahanova
;
Matthew Chidozie Ogwu
;
Zhexenbek Toktarbay
;
Zoya Umirbayeva
Antibiotic residues in the poultry food products pose significant public health risks, contributing to the growing global challenge of antimicrobial resistance (AMR). This paper focuses on the public health risks associated with antibiotic residues in poultry food products. The study found that the routine use of antibiotics in poultry farming for growth promotion and disease prevention has resulted in the accumulation of residues in food products, which can lead to adverse health effects in consumers. These include allergic reactions, toxicity, disruption of gut microbiota, and the promotion of antibiotic-resistant bacteria. Long-term exposure to antibiotic residues, even at low levels, exacerbates these risks, impacting not only individual health but also broader public health systems. Regulatory frameworks, such as the establishment of maximum residue limits (MRLs) and stringent monitoring, are crucial for ensuring food safety. However, there is a pressing need for alternative strategies in poultry production that reduce reliance on antibiotics while maintaining animal health. Public education, antimicrobial stewardship, and sustainable farming practices are vital to mitigate the risks posed by antibiotic residues. The global effort to address AMR should involve coordinated actions among stakeholders, including policymakers, farmers, and healthcare providers, to protect both food safety and public health. Future research needs to prioritize the development of alternative therapeutics and innovative farming practices to minimize the presence of antibiotic residues in poultry products. • Use of antibiotics in poultry could boost growth and wellbeing but also pose public health risks. • Ongoing misuse is driving an increase in environmental and organismal antibiotic residues. • Antibiotic residues can accumulate through the food chain with known and unknown One Health effects. • Factors affecting residues include antibiotic type, dosage, withdrawal and cultural practices. • Cooking reduces antibiotic residues, but consumption of poultry products may cause allergic and microbiota effects.
Цитирования (OpenAlex) 38Цитирования (OpenCitations) 14
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Joule-heat derived amorphous/graphitic polymer nanotubes with enhanced electromagnetic wave absorption and high thermal conductivity
(Elsevier BV, 2025-05-16)
Yang Cao
;
Xinfei Zeng
;
Jingtao Su
;
Wentao Yu
;
Haichen Zhang
The rapid advancement of artificial intelligence demands multifunctional materials integrating electromagnetic wave absorption (EWA) and thermal management capabilities for next-generation electronics. Herein, a facile and scalable Joule-heating carbonization strategy is proposed to regulate the amorphous-to-graphitic phase ratio in polymer nanotubes, achieving a precise modulation of EWA performance. The nitrogen species transformation during carbonization induced enhanced polarization relaxation, defect generation, and dipole polarization, synergistically facilitating charge transfer. Polypyrrole-based polymer nanotubes treated at 1000 o C (PNT-1000) exhibited a maximum effective absorption bandwidth of 3.46 GHz and a minimum reflection loss of −45.1 dB. Moreover, PNT-1000@polydimethylsiloxane (PDMS) demonstrated a thermal conductivity of 2.26 W/(mK), while PNT-2000@PDMS achieved a significantly higher thermal conductivity of 4.20 W/(mK). This work systematically elucidated the interaction between amorphous and graphitic phases in controlling both EWA and thermal conductivity, which is helpful for applying carbon-based materials in these advanced fields.
Цитирования (OpenAlex) 68Цитирования (OpenCitations) 43
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Coaxial electrospun PEG-4000@PVDF composite membranes with intumescent flame retardants: Toward multifunctional fabrics for thermal management and ultra-safe lithium-ion battery separators
(Elsevier BV, 2025-07-18)
Yongshuang Xiao
;
Jiahui Lin
;
Yang Cao
;
Xin Liu
;
Hao Wang
• Multifunctional core-shell fiber films were prepared by one-step coaxial electrospinning technique. • Efficient halogen-free synergistic intumescent flame retardant system. • Films exhibit superior phase-change enthalpy, shape stability and flame retardant properties. • Core-shell dual functionality enables simultaneous thermal regulation and flame retardancy for fabrics and lithium-ion battery separators. Phase change materials (PCMs) like PEG-4000 offer high heat storage density and can isothermally store or release energy. However, there are fatal safety problems, such as leakage and flammability during transition, which greatly limit the practical application. To address these issues, coaxial electrospinning was employed to fabricate multifunctional core–shell structured fibers, encapsulating PEG-4000 within a polyvinylidene fluoride (PVDF) shell integrated with halogen-free intumescent flame retardants (IFR). The resulting PEG-4000@PVDF-IFR (PPI) composite fibers exhibit superior thermal stability, shape stability, and flame retardancy. Among them, PPI-3 exhibits a synergistic flame-retardant effect, with a high storage density of 92.26 J g −1 and a V-0 rating in modified UL-94 tests. Compared to PEG-4000, PPI-3 reduces the total heat release (THR) by 51.59 % and increases the char residue from 1.51 % to 15.15 %, significantly enhancing the flame retardancy. The PPI coaxial fiber membrane, featuring a well-designed core–shell structure, combines high porosity, large specific surface area, and superior flexibility, simultaneously enhancing traditional textile comfort and thermal regulation while effectively mitigating thermal runaway risks in lithium-ion batteries. In conclusion, PPI shows considerable potential for application in thermal management applications.
Цитирования (OpenAlex) 75Цитирования (OpenCitations) 36
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ADSORBENTS BASED ON MODIFIED NANOCELLULOSE: WATER PURIFICATION FROM ORGANIC AND INORGANIC POLLUTANTS
(Shakarim University, 2026-07-29)
Zhexenbek Toktarbay
;
Makhabbat Kunarbekova
;
B. U. Rakhimova
;
Kenes Kudaibergenov
;
Dana Ashiraliyeva
Against the backdrop of rapid industrial growth, water pollution has become a pressing global environmental issue. This review provides a systematic analysis of the efficiency of functionalized nanocellulose- based adsorbents for the removal of organic (synthetic dyes, phenols, antibiotics, pesticides) and inorganic (Pb 2+ , Cd 2+ , Hg 2+ , Cr(VI), Cu 2+ , As) pollutants from water. Key findings: the highest sorption capacities are achieved by TEMPO-oxidized nanocellulose and amine-functionalized composites – up to 2500 mg/g for methylene blue and up to 2270 mg/g for lead ions. Nanocellulose-based molecularly imprinted polymers (MIPs) selectively adsorb phenols with efficiencies of up to 97% even in the presence of structurally similar competitors. Most adsorbents reviewed retain 80+90% of their capacity after 20 regeneration cycles. The paper examines three main types of nanocellulose (CNC, NFC, BNC), their preparation methods (acid hydrolysis, TEMPO-oxidation, mechanical and enzymatic treatment), and surface functionalization strategies (isocyanate-based, amine- and thiol-functionalization). The alignment of nanocellulose production from agricultural waste (rice husks, soybean hulls) with sustainable development principles is emphasized. Key unresolved challenges – scale-up, stability in real wastewater matrices, and cost-effectiveness – and future research directions are also identified.

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