Acrylamide Research Articles

Preparation of Thermoresponsive Microgels from Acrylamide and Diacetone Acrylamide with Adjustable Responsive Temperature and Size via Precipitation Polymerization

AbstractThermoresponsive microgels are a kind of soft and wet material exhibiting various potential applications such as smart windows. As a concept of proof, poly(N‐isopropylacrylamide) based thermoresponsive microgel shows excellent promise in thermochoromic smart windows. While relatively expensive monomers lead to an unacceptable cost when they are used as building materials. In this work, efforts are made to exploration of an alternative for poly(N‐isopropylacrylamide) reducing the cost of thermoresponsive microgels. For this purpose, industrial chemicals acrylamide (AM) and diacetone acrylamide (DAAM) are employed to synthesize microgels through free radical precipitation polymerization. Although both homopolymers of acrylamide and diacetone acrylamide are not thermoresponsive. Their copolymers exhibit typical lower solution temperature solution (LCST) behaviors, which confirm the feasibility of the envisaged. Further, the influence of synthetic conditions including monomer ratio, concentration of surfactant, and polymerization temperature, on the size and responsive temperature of microgels is investigated. Ultimately, cost‐effective thermoresponsive microgels are prepared with adjustable diameters from 1.6 to 4.5 µm and responsive temperature from 19.3 to ≈70.0 °C.

Structure-Controllable and Mass-Produced Glycopolymersomes as a Template of the Carbohydrate@Ag Nanobiohybrid with Inherent Antibacteria and Biofilm Eradication.

Glycopolymer-supported silver nanoparticles (AgNPs) have demonstrated a promising alternative to antibiotics for the treatment of multidrug-resistant bacteria-infected diseases. In this contribution, we report a class of biohybrid glycopolymersome-supported AgNPs, which are capable of effectively killing multidrug-resistant bacteria and disrupting related biofilms. First of all, glycopolymersomes with controllable structures were massively fabricated through reversible addition-fragmentation chain transfer (RAFT) polymerization-induced self-assembly (PISA) in an aqueous solution driven by complementary hydrogen bonding interaction between the pyridine and amide groups of N-(2-methylpyridine)-acrylamide (MPA) monomers. Subsequently, Ag+ captured by glycopolymersomes through the coordination between pyridine-N and Ag+ was reduced into AgNPs stabilized by glycopolymersomes upon addition of the NaBH4 reducing agent, leading to the formation of the glycopolymersome@AgNPs biohybrid. As a result, they showed a wide-spectrum and enhanced removal of multidrug-resistant bacteria and biofilms compared to naked AgNPs due to the easier adhesion onto the bacterial surface and diffusion into biofilms through the specific protein-carbohydrate recognition. Moreover, the in vivo results revealed that the obtained biohybrid glycopolymersomes not only demonstrated an effective treatment for inhibiting the cariogenic bacteria but also were able to repair the demineralization of caries via accumulating Ca2+ through the recognition between carbohydrates and Ca2+. Furthermore, glycopolymersomes@AgNPs showed quite low in vitro hemolysis and cytotoxicity and almost negligible acute toxicity in vivo. Overall, this type of biohybrid glycopolymersome@AgNPs nanomaterial provides a new avenue for enhanced antibacterial and antibiofilm activities and the effective treatment of oral microbial-infected diseases.

Well‐defined poly(N,N‐dimethylacrylamide) from a fast Cu(0)‐mediated reversible‐deactivation radical polymerization in water

AbstractCopper‐catalyzed reversible deactivation radical polymerization (RDRP) of N,N‐dimethylacrylamide (DMA) has been a significant challenge, particularly in aqueous environments, such as low yields, broad molecular weight distribution (MWD), and ill‐controlled molecular weights (MWs). In this work, we report the synthesis of well‐defined poly(N,N‐dimethylacrylamide) (PDMA) via a facile Cu(0)‐mediated RDRP in water. The results show that, unlike other acrylamide monomers, for DMA with abundant tertiary amide groups, the sufficient deactivation—the key to realizing control in copper‐catalyzed RDRP—cannot be simply fulfilled by just increasing the amount of deactivator (i.e., CuII species). The enhanced deactivation must be appropriately determined by also considering and selecting other reaction parameters. It is demonstrated that the use of methyl 2‐chloropropionate (MCP) as initiator and copper(II) chloride (CuCl2) as the additional catalyst is an effective combination to simultaneously enhance the deactivation control and facilitate the chain growth in aqueous Cu(0)‐mediated RDRP of DMA. This strategy successfully achieved the fast and well‐controlled synthesis of PDMAs with high monomer conversion, narrow MWDs, and a range of predefined MWs, and the well‐controlled in situ chain extensions.

Radiation synthesis and chemical modifications of p(AAm-co-AAc) hydrogel for improving their adsorptive removal of metal ions from polluted water

The research focuses on utilizing gamma irradiation to synthesize polyacrylic acid-co-polyacrylamide p(AAm-co-AAc) hydrogels. The effect of synthetic parameters on physicochemical features of p(AAm-co-AAc) hydrogls were examined, including acrylic acid (AAc): acrylamide (AAm) weight ratios, monomer concentration, and gamma irradiation dosage (kGy). At the optimum synthetic conditions (30 kGy and 75% AAc), different chemical modifications are explored to incorporate sulfonate, hydroxyl, carboxyl, cysteine, thiol, and amine functional groups within the bare hydrogel (Cpd 0) structure. Fourier-transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM) analyses confirmed the success development of functionalized hydrogels (namely Cpd 1 to 6) with three-dimensional porous structures. These modified hydrogels include Cpd 1, a sulfonated hydrogel through a sulfonation reaction; Cpd 2, modified via NaOH hydrolysis; Cpd 3, modified using thionyl chloride; Cpd 4, incorporating cysteine modification through reaction with cysteine; Cpd 5, with 4-(Dimethylamino) benzaldehyde; and Cpd 6, modified with 3,4-Dimethylbenzoic acid.The effect of hydrogel composition and surface functionalities on the swelling capacity and interactions with scale-forming/heavy metal ions (e.g., Ba2+, Sr2+, and Cu2+) was investigated in saline water solution (NaCl = 1000 mg/L). Batch adsorption studies reveal that all modified hydrogels exhibited higher removal efficiency for the three metal ions than unmodified p(AAm-co-AAc) hydrogel, validating the key role of surface functionalities in tailoring hydrogel affinity for metal ions adsorption. Amongst these, NaOH-treated hydrogel (Cpd 2) outperformed all other modified ones in the removal of Cu2+, Ba2+, and Sr2+ ions, with maximum capacities of 13.67, 36.4, and 27.31 mg/g, respectively. Based on adsorption isotherm and kinetic modeling, the adsorption process of the three metal ions onto all modified hydrogels better obeyed Freundlich isotherm and pseudo-first-order kinetic models. Thermodynamic studies also indicated that the adsorption behavior of Sr2+ ions can exhibit both exothermic and endothermic characteristics, depending on the nature of hydrogel surface chemistry. Conversely, the adsorption process of Cu2+ and Ba2+ ions onto all modified hydrogels is endothermic, suggesting favorable chemical adsorption mechanisms. These findings reveal that the specific adsorption performance of hydrogel is dependent on the type of modification and the targeted heavy metal ions. Based on the nature of hydrogel surface functionality, surface modifications can change the charge density, hydrophilicity, and overall chemical environment of the hydrogel, offering a versatile approach to optimize the adsorption affinity/selectivity of hydrogel's in removing scale-forming/heavy metals from water solutions.

Grafted copolymers based on HPMC with excellent thermo-viscosifying and salt-tolerant properties at low concentration for enhanced oil recovery

The conventional acrylamide-based polymers are greatly restricted under the reservoir conditions of high temperature and high salt due to their linear molecular structures. In this article, a grafted water-soluble copolymer based on hydroxypropyl methyl cellulose (HPMC) with excellent thermal viscosifying and salt-tolerant properties at low concentration was prepared via the “graft from” method, with acrylamide (AM) and methyl allyl polyoxyethylene ether (HPEG) as grafted monomers. The structure of the copolymer was identified by 1H nuclear magnetic resonance spectroscopy (1H NMR), Fourier transform infrared spectroscopy (FT-IR), thermogravimetric analysis (TGA) and scanning electron microscopy (SEM). The basic displacement properties of the copolymers under extreme conditions were systematically studied. The results showed that due to the symbiotic effects of the rigid heterocyclic structure of HPMC and the hydrophobic inter-molecular aggregation of thermosensitive HPEG units in the copolymer chain, the copolymer exhibited better thermal thickening ability (the viscosity enhancements changes from 7.1 to 19.9 times from 25 °C to 95 °C in brine solution with total salinity 9350.08 mg.L−1), salt resistance (the viscosity enhancements changes from 1.13 to 2.29 times with salts concentration from 0.0 wt% to 2.0 wt% at 85 °C), shear tolerance (the viscosity retention rate was from 18.6% to 24.2% at 1000s−1) and anti-aging properties (the viscosity retention rate up to 73.7% at 65 °C for three weeks) than polyacrylamide at low concentration (0.2 wt%). Furthermore, the polymer flooding test showed that the copolymer yielded a higher recovery rate of 23.2% higher than that yielded by polyacrylamide (14.5%), elucidating that the copolymer synthesized herein was suitable for enhanced oil recovery in reservoirs with severe conditions.

Synthesis and properties of self‐healing hydrogel plugging agent

AbstractThe P(AM‐co‐AMPS)/SA DN hydrogel was synthesized through aqueous polymerization in this study. It formed a crosslinking network with hydrophobic associations between acrylamide (AM) and lauryl methacrylate (LMA), as well as an ionic bond network involving sodium alginate and Ca2+. To enhance its high‐temperature resistance, 2‐acrylamide‐2‐methylpropane sulfonic acid (AMPS) was incorporated into the hydrogel formulation. The structure of the hydrogel was characterized using Fourier transform infrared spectrometer (FTIR), thermogravimetric analyzer (TGA), and scanning electron microscopy (SEM) techniques. Results demonstrated that the hydrogel exhibited excellent temperature resistance and possessed a porous structure. Mechanical testing revealed a high tensile strength of 110 kPa, elongation at break of 995.31%, along with good fatigue resistance and self‐recovery performance during multiple cyclic stretching. Healing experiments indicated that the healing strength of the hydrogel was influenced by temperature variations. Furthermore, pressure plugging tests were conducted on steel models with crack widths of 0.5 and 1 mm, respectively; it was found that the 0.8%P(AM‐co‐AMPS)/SA DN hydrogel could withstand pressures up to 4.5 MPa at a temperature of 70°C. This novel hydrogel material exhibits remarkable mechanical properties along with certain self‐healing capabilities, making it suitable for leak control applications.

Ultra-High-Molecular-Weight, Narrow-Polydispersity Polyacrylamides Synthesized Using Photoiniferter Polymerization to Generate High-Performance Flocculants.

Ultra-high-molecular-weight, water-soluble polyelectrolytes are commonly employed as flocculants for solid-liquid separation via colloidal destabilization, enabling the rapid and efficient removal of particulate matter from wastewater streams. A drive toward more sustainable and less polluting industrial practices, coupled with the desire to reduce freshwater usage and improve closed-loop systems, demands the development of flocculants with ever-higher dewatering dose performance. Herein, the use of trithiocarbonate-mediated reversible addition-fragmentation chain transfer (RAFT) polymerization under either blue LED (λmax = 470 nm) or UV (λmax = 365 nm) irradiation, known as photoiniferter polymerization, was successfully utilized to generate ultra-high-molecular-weight (Mn > 1,000,000 g mol-1) polyelectrolyte copolymer flocculants with narrow molecular weight distributions (Mw/Mn < 1.2). Cationic and anionic polyelectrolyte flocculants were synthesized containing various monomer compositions of acrylamide (AM), dimethylacrylamide (DMA), 3-(acryloyloxyethyll)trimethylammonium chloride (DMAEAq), 3-(acrylamidopropyl)trimethylammonium chloride (APTAC), sodium acrylate (NaAA), and sodium 2-(acrylamido)-2-methylpropylsulfonate (NaATBS) with high monomer conversion using simple experimental apparatus. The narrow molecular weight distribution cationic polyelectrolytes showed improved flocculation efficiency in the clarification of kaolin suspensions of up to 50% in comparison to a broad polydispersity (Mw/Mn > 5.0) commercial benchmark with an equivalent number average molecular weight. The improved performance of the narrow-polydispersity copolymers is attributed to the reduction in the content of the lower-molecular-weight polymer chains, which impart lower flocculation performance.

Synthesis and mechanism study of an environmentally friendly filtrate reducing agent from humic acid and organic silicon

AbstractIn this study, organic silicon was introduced to humic acid for the first time, and set the novel polymer NaHm/AMPS/AM/TSP‐L12 (HASSi) as an environmentally friendly filtrate reducing agent, which was developed by using silica modified material (TSP‐L12), sodium humic acid (NaHm), 2‐acrylamido‐2‐methylpropanesulfonic acid sodium (AMPS), and acrylamide (AM) as raw materials. The molecular structure, chemical composition of HASSi has been investigated and results show that HASSi shows the chemical structure was conformed to the molecular design. Differential scanning calorimetry–thermogravimetric analysis results illustrate that thermal decomposition temperature of HASSi under nitrogen was 250°C. Though temperature resistance evaluations, HASSi could withstand temperature up to 230°C. Salt and calcium resistance evaluations confirmed its resistance of NaCl could reach up to 5% and CaCl2 to 0.5%. The filtrate reduce mechanism of HASSi was investigated through various methods, including scanning electron microscope analysis of HASSi aqueous solution, microstructure of filter cake, measurements of zeta potential, and particle size distribution, results showed that HASSi participation in the formation of mud cakes and illustrated an excellent filtration reduction effect. In addition, HASSi was identified as an environmentally friendly filter loss reducing agent through environmental performance evaluation, which shows a great application prospect in oilfield.

The multi-sensitive ion-imprinted polymer as a selective absorbent for the separation of ruthenium

In this study, a multi-sensitive ion-imprinted polymer that serves as a highly selective absorption material for ruthenium (Ru(III)) in complicated solutions was designed and prepared with the adoption of Pickering High Internal Phase Emulsions (HIPEs) polymerization technology. Meawhile, acrylamide (AM) and acrylic acid (AA) were used as functional monomers, Ru(III) as template ion, ethylene glycol dimethacrylate (EGDMA) as cross-linking agent and the redox system ammonium persulfate-N,N,N′,N′-tetramethylethylenediamine (AP-TEMED) as initiator for the synthesis of a smart ruthenium ion-imprinted polymer (Ru(III)–SIIP). The chemical structure, morphology and magnetic properties of Ru(III)–SIIP were characterized and subsequently used for the selective adsorption of Ru(III). The results revealed that Ru(III)–SIIP had obvious temperature sensitivity/pH sensitivity/magnetic sensitivity. The maximum adsorption capacity of Ru(III) was 0.191 mmol/g and coupled with a desorption ratio of 82.99%. The screening of the adsorption kinetics of Ru(III)–SIIP indicated that the zero-order and pseudo-first-order kinetic mixed model was more suitable for describing the adsorption process, while the Langmuir model was suitable for describing the isotherm of Ru(III)–SIIP. Furthermore, an adsorption method combined with inductively coupled plasma atomic emission spectrometry (ICP-AES) based on Ru(III)–SIIP was established for Ru(III) and successfully applied in the detection of Ru(III) in mixed solutions. To conclude, Ru(III)–SIIP has broad prospects for the recovery of ruthenium in complex environmental situations.

Sodium Alginate/Zwitterionic Polymer Gel Electrolyte for Integrated All‐Solid‐State Supercapacitors

AbstractAll‐solid‐state stretchable supercapacitors (SSSCs) have attracted widespread attention in the wearable and medical fields because of their nontoxic, safe, and environmentally friendly characteristics. In this paper, a dual network hydrogel polymer was synthesized by a one‐pot method, which was constructed from sodium alginate (SA) and zwitterion copolymer of acrylamide (AM) and sulfobetaine methacrylate (SBMA). The dual network hydrogel polymerSAm/P(AM‐co‐SBMA (SASm for short) were immersed in 1 M H2SO4 electrolyte to obtain gel polymer electrolytes (GPEs). Stretchable electrodes were synthesized on the matrix of SASm gels. Non‐integrated all‐solid‐state stretchable supercapacitors (non‐integrated SSSCs), integrated all‐solid‐state supercapacitors (SSCs) and integrated SSSCs were all assembled into the ‘sandwich’ structure. The elongation of the integrated SSSC is the best and reaches 280 %, and its areal capacitance is 1.96 mF/cm2 under a current destiny of 50 μA/cm2, and the capacitance still remains 95 % of the initial value after 10000 charge and discharge cycles, and its energy density is 5.8×10−2 μWh/cm2 at a power density of 2.9×10−2 mW/cm2. This integrated SSSC has excellent cycling stability while maintaining good tensile properties.

High-fat diet exacerbated motor dysfunction via necroptosis and neuroinflammation in acrylamide-induced neurotoxicity in mice

Health risks associated with acrylamide (ACR) or high-fat diet (HFD) exposure alone have been widely concerned in recent years. In a realistic situation, ACR and HFD are generally co-existence, and both are risk factors for the development of neurological diseases. The purpose of the present study was to investigate the combined effects of ACR and HFD on the motor nerve function. As a result, neurobehavioral tests and Nissl staining disclosed that long-term HFD exacerbated motor dysfunction and the damage of spinal cord motor neurons in ACR-exposed mice. Co-exposure of ACR and HFD resulted in morphological changes in neuronal mitochondria of the spinal cord, a significantly reduced mitochondrial subunits NDUFS1, UQCRC2, and MTCO1, released the mitochondrial DNA (mtDNA) into the cytoplasm, and promoted the production of reactive oxygen species (ROS). Combined exposure of HFD and ACR activated the calpain/CDK5/Drp1 axis and caused the mitochondrial excessive division, ultimately increasing MLKL-mediated necroptosis in spinal cord motor neurons. Meanwhile, HFD significantly exacerbated ACR-induced activation of NFkB, NLRP3 inflammasome, and cGAS-STING pathway. Taken together, our findings demonstrated that combined exposure of ACR and HFD aggravated the damage of spinal cord motor neurons via neuroinflammation and necroptosis signaling pathway, pointing to additive effects in mice than the individual stress effects.

Synthesis of Multifunctional Polymers Based on Tert-Butyl Acrylamide/Octyl Acrylate as Lubricant Additives and Adsorbents for Copper Ion from Aqueous Solution

Two homopolymeric and three copolymeric additives for base oil were synthesized using octyl acrylate (OA) and tert-butyl acrylamide (TBA) monomers. The two additives named P1 and P2 are the homopolymers of TBA and OA, respectively, whereas copolymeric additives named Co1, Co2, and Co3 were synthesized by varying the ratios of TBA:OA as 1:3, 3:1 and 1:1, respectively. The prepared polymers were characterized by Fourier Transform Infrared (FTIR). Based on the solubility of synthesized polymers in base oil and reactivity ratios of TBA/OA copolymer (0.222, 0.434) calculated by Fineman-Ross method, P2, Co1, Co2 and Co3 were selected to evaluate their performance as pour point depressant (PPD), viscosity improver (VII), and anticorrosion additives in base oil. Additives P2 and Co1 showed the best performance as (PPD) and (VII) whereas Co2 and Co3 revealed the best performance as anticorrosion additives. The flash point of base oil increased as a concentration of polymeric additives increased in the base oil. In addition to study the performance of synthesized polymers as lubricant additives, the capability of polymers for removing CuII from synthetic wastewater was also investigated. Different parameters such as pH of solution, contact time, and CuII concentration were changed in order to study their effect on adsorption capacity of polymers. Generally, polymers with high TBA content such as P1, Co2, and Co3 showed good performance in removing CuII.

Polymerization of Acrylamide N-methylene Lactic and Glycolic Acid

In this research work, the novel polymer base on acrylamide N-methylene lactic and glycolic acid was synthesized and its structural performances were identified by the IR, 1H NMR and 13C NMR spectroscopic investigations. The influencing factors and kinetics of polymerization, viscosity performance were studied and quantum chemical calculations were used to identify the correlation between the structure and properties. It was determined that the polymerization rate of the examined monomers in an aqueous solution, in the presence of DAA, adheres to the standard rules for radical polymerization of acrylamide monomers in solution. An investigation into the pH solution's impact on the kinetics of radical polymerization of acrylamido-N-methylene glycolic and acrylamido-N-methylene lactic acids revealed an extreme dependence with a minimum in a neutral medium. It was found the linear correlation between pH and viscosity. The physical and chemical performance of this polymer depends on the structural parameters related the results of quantum chemical calculation. Biological tests conducted on polyacrylamido-N-methylene lactic acid indicated its potential as a plant growth stimulator. The polymeric form of lactic acid was found to enhance the growth of Dustlik variety wheat seedlings by 40% more efficiently than lactic acid alone.

Polypyrrole participates in the construction of a polarity-switchable photoelectrochemical molecularly imprinted sensor for the detection of acrylamide in fried foods

Designing a polarity-switchable photoelectrochemical (PEC) sensor is important, but there are significant challenges due to the difficulty in adjusting the polarization of photoelectric or photoactive materials. In this manuscript, we established a simple and polarity-switchable molecularly imprinted polymer (MIP)-PEC sensor based on a “Z-scheme” strategy for detecting acrylamide (AM). First, we prepared a composite material of MoS2/rGO/Au (MGA) with a large specific surface area and good electrical conductivity that was sensitive to visible light. Second, the photoactive material MGA was used as the substrate material and polypyrrole (PPy) was acted as the functional monomer associated with the template molecule AM to construct the MIP working electrodes. PPy not only dressed up as a functional monomer but also as a polarity switcher, creating an in-situ-grown PPy/MGA heterojunction with a charge-carrier transport path similar to the letter “Z.” The design of the Z-scheme strategy not only increased the signal intensity of the photocurrent but also switched the photocurrent polarity from the anode to the cathode, avoiding the interference of a false positive or a false negative. When using this PEC-MIP sensor for the quantitative detection of AM, the detection limit was 1.7 pmol for the linear range of 0.25–10000 nmol. The proposed sensor exhibited satisfactory sensitivity and selectivity, and it has great potential for monitoring emerging food safety risks.

Biochemical characterization of glutaminase-free L-asparaginases from Himalayan Pseudomonas and Rahnella spp. for acrylamide mitigation

L-asparaginase having low glutaminase activity is important in clinical and food applications. Herein, glutaminase-free L-asparaginase (type I) coding genes from Pseudomonas sp. PCH182 (Ps-ASNase I) and Rahnella sp. PCH162 (Rs-ASNase I) was amplified using gene-specific primers, cloned into a pET-47b(+) vector, and plasmids were transformed into Escherichia coli (E. coli). Further, affinity chromatography purified recombinant proteins to homogeneity with monomer sizes of ~37.0 kDa. Purified Ps-ASNase I and Rs-ASNase I were active at wide pHs and temperatures with optimum activity at 50 °C (492 ± 5 U/mg) and 37 °C (308 ± 4 U/mg), respectively. Kinetic constant Km and Vmax for L-asparagine (Asn) were 2.7 ± 0.06 mM and 526.31 ± 4.0 U/mg for Ps-ASNase I, and 4.43 ± 1.06 mM and 434.78 ± 4.0 U/mg for Rs-ASNase I. Circular dichroism study revealed 29.3 % and 24.12 % α-helix structures in Ps-ASNase I and Rs-ASNase I, respectively. Upon their evaluation to mitigate acrylamide formation, 43 % and 34 % acrylamide (AA) reduction were achieved after pre-treatment of raw potato slices, consistent with 65 % and 59 % Asn reduction for Ps-ASNase I and Rs-ASNase I, respectively. Current findings suggested the potential of less explored intracellular L-asparaginase in AA mitigation for food safety.

Determinants of exposure to acrylamide in European children and adults based on urinary biomarkers: results from the “European Human Biomonitoring Initiative” HBM4EU participating studies

Little is known about exposure determinants of acrylamide (AA), a genotoxic food-processing contaminant, in Europe. We assessed determinants of AA exposure, measured by urinary mercapturic acids of AA (AAMA) and glycidamide (GAMA), its main metabolite, in 3157 children/adolescents and 1297 adults in the European Human Biomonitoring Initiative. Harmonized individual-level questionnaires data and quality assured measurements of AAMA and GAMA (urine collection: 2014–2021), the short-term validated biomarkers of AA exposure, were obtained from four studies (Italy, France, Germany, and Norway) in children/adolescents (age range: 3–18 years) and six studies (Portugal, Spain, France, Germany, Luxembourg, and Iceland) in adults (age range: 20–45 years). Multivariable-adjusted pooled quantile regressions were employed to assess median differences (β coefficients) with 95% confidence intervals (95% CI) in AAMA and GAMA (µg/g creatinine) in relation to exposure determinants. Southern European studies had higher AAMA than Northern studies. In children/adolescents, we observed significant lower AA associated with high socioeconomic status (AAMA:β = − 9.1 µg/g creatinine, 95% CI − 15.8, − 2.4; GAMA: β = − 3.4 µg/g creatinine, 95% CI − 4.7, − 2.2), living in rural areas (AAMA:β = − 4.7 µg/g creatinine, 95% CI − 8.6, − 0.8; GAMA:β = − 1.1 µg/g creatinine, 95% CI − 1.9, − 0.4) and increasing age (AAMA:β = − 1.9 µg/g creatinine, 95% CI − 2.4, − 1.4; GAMA:β = − 0.7 µg/g creatinine, 95% CI − 0.8, − 0.6). In adults, higher AAMA was also associated with high consumption of fried potatoes whereas lower AAMA was associated with higher body-mass-index. Based on this large-scale study, several potential determinants of AA exposure were identified in children/adolescents and adults in European countries.

Thiol-ene click derivatization reaction coupled with ratiometric surface-enhanced Raman scattering for reproducible and accurate determination of acrylamide.

Acrylamide (AA) is a carcinogen mainly ingested through food and drinking water, making its accurate determination crucial for both food safety and environmental protection. Herein, we proposed a derivatization-based ratiometric surface-enhanced Raman scattering (SERS) method for the quantification of AA. High density Au NPs were anchored to the surface of Cu-TCPP MOF nanosheets (MOFNs) to form the SERS sensor. The abundant Raman "hot spots" at the nanogaps generated by the Au NPs and the internal standard (IS) signal provided by Cu-TCPP MOFNs improved the sensitivity and quantitative accuracy of the method. Following the thiol-ene click derivatization reaction between p-aminothiophenol (PATP) and AA, the Raman peak intensity ratio (I1080/I395) was employed to quantify AA. The linear range was 0.1nM to 10μM, and the limit of detection (LOD) was as low as 0.08nM. Trace amounts of AA in food and water samples were successfully determined using this method.

Removal of Malachite Green by Poly(acrylamide-co-acrylic acid) Hydrogels: Analysis of Coulombic and Hydrogen Bond Donor-Acceptor Interactions.

Water pollution caused by dyes poses a significant threat to life on earth. Poly(acrylamide-co-acrylic acid) hydrogels are widely used to treat wastewater from various pollutants. This study aims to examine the removal of malachite green (MG), a harmful and persistent dye that could cause extensive environmental damage, from an aqueous solution by adjusting the initial concentration of acrylamide (AM) and the degree of copolymer crosslinking. The copolymer hydrogels efficiently eliminate MG in a brief timeframe. The most successful hydrogel accomplished a removal rate exceeding 96%. The copolymer of 4 wt % 1,6-hexanediol diacrylate and a concentration of 100 mg/mL AM was effective. The degree of swelling was affected by crosslinking density as expected, with low crosslinking ratios resulting in significant swelling and high ratios resulting in less swelling. To evaluate the results, a docking approach was used which presented three crosslinked models: low, medium, and high. The copolymer-dye hydrogel system displayed robust hydrogen bonding interactions, as confirmed by the high quantities of both donors and acceptors. It was determined that MG contains six rotatable bonds, enabling it to adapt and interact with the copolymer chains. The dye and copolymer enhance H-bond formation by providing two hydrogen bond donors and 16 hydrogen bond acceptors, respectively. Through capitalizing on cationic and anionic effects, the ionic MG/copolymer hydrogel system improves retention efficiency by enhancing attraction between opposing charges. It is interesting to note that the synthesized copolymer is able to remove 96.4% of MG from aqueous media within one hour of contact time.

Novel superabsorbent polymer composite embedded with sodium alginate and diatomite for excellent water absorbency, water retention capacity, and high thermal stability

The low water absorbency, poor thermal stability, and high cost of absorbent polymers remain significant challenges that need addressing to broaden their range of applications. To address these drawbacks of superabsorbents, a novel superabsorbent polymer composite (SAPc) SA-g-P(AA-co-AM)/MDE was developed using a simple aqueous polymerization method involving sodium alginate (SA), modified diatomite (MDE), acrylic acid (AA), and acrylamide (AM). The synthesized materials were systematically characterized using various techniques, including FT-IR, SEM, and XRD, to determine their chemical structure, morphology, and crystal structure. The water absorbency capacity (WAC) of SA-g-P(AA-co-AM)/MDE increased with increasing SA dosage, but it gradually declined once it exceeded 5 wt.%. The SAPc with the highest water absorbency was obtained when the SA content was 5 wt.% in both distilled water and NaCl solution. The absorption data of SA-g-P(AA-co-AM)/MDE fit well with the pseudo-first-order (PFO) kinetic model. The results of water retention capacity (WRC) demonstrated that the water-retaining time of the SAPc increased by 39.0 % compared to P(AA-co-AM). Additionally, thermal gravimetric analysis revealed that the introduction of MDE and SA enhanced the SAPc's thermal stability. Therefore, this study demonstrates that the introduction of SA and MDE can lead to SAPc with outstanding WAC, WRC, and thermal stability. These findings suggest that the SAPc prepared in this study could be a promising material for use in agriculture, industry, and sanitary goods.

Transparent electromagnetic absorption film derived from the biomass derivate

Electromagnetic wave absorption materials featuring small thicknesses and wide effective absorption bandwidth (EAB) are highly required for next-generation portable devices, wearable electronics, and blooming military applications. However, traditional EM particle absorbents, such as carbon-based, magnetic metal-based, and MXene-based materials are always visible black, which severely hinders their utilization as microwave-stealth smart window alternatives. Therefore, it is a critical challenge to fabricate flexible windows simultaneously possessing high optical transmittance and excellent EM wave absorption properties. Herein, we prepared a transparent wood composite with an optical transmittance value of more than ∼83% through a delignification and polymer composite immersion method. The delignification process could remove the light-absorbing lignin component, and the transparent woods were realized by immersing the delignified wood into refractive-index-matched pre-polymerized acrylamide (AM) including minor silver nanowires, carbon nanotubes, and reduced graphene oxides. In addition, due to the presence of numerous polarization centers originating from hydrophilic functional groups and conductive fillers, the transparent wood composite showed superior EM absorption performance, and EAB can reach 9.5 GHz, almost occupying the whole X band (8.2–12.4 GHz) and Ku band (12.4–18 GHz) at a thickness of 2.0 mm. Furthermore, the transparent wood presented a great insulative thermal performance with a low thermal conductivity of 0.45 W m−1 K−1 (half of common glass). The developed transparent wood composites offered significant potential as smart energy-efficient windows with the expectation to survive military equipment and alleviate EM pollution.