Monomer Ratio Research Articles

Thermosensitive ZnO-PMMA/PEG microgels: A smart sunscreen with adapting SPF to ambient temperature fluctuations

Increasing awareness of the importance of ultraviolet protection has led to the development and utilization of sunscreen products. The sun protection factor (SPF) value of traditional sunscreens is fixed and cannot be flexibly adapted to changing environmental requirements. Herein, we fabricate a series of thermosensitive ZnO-poly (methyl methacrylate)/nonlinear poly(ethylene glycol) (PMMA/PEG) core-shell microgel with different monomer ratios. The PMMA core particle is designed to immobilize ZnO nanoparticles for achieving high loading capacity, and the hydrophilic nonlinear PEG gel shell possesses good biocompatibility and provides adjustable SPF value in response to different environmental conditions. The prepared microgels are monodisperse spherical with a well-defined core-shell morphology. The shell thickness of the microgels can be easily controlled by changing the feeding ratios of shell precursors. The optimized ZnO-PMMA/PEG microgels display significant sun protection properties at a concentration of 10 wt% (SPF 45 ± 5.9, 20 °C) and enhanced UV resistance performance as the temperature increases (SPF 53.1 ± 1.1, 37 °C). Both cell and mouse experiments confirmed the limited skin penetration potential of the microgels and their good compatibility with biological systems. This developed ZnO-PMMA/PEG microgels exhibit promising application potential in intelligent sunscreen technology.

Wood consolidation through an epoxy‐acrylic gamma‐crosslinked three‐dimensional system

AbstractEmerging technologies based on polymeric materials are progressively developed in order to preserve and consolidate cultural heritage artifacts. In this study, we aimed to obtain a hybrid polymer reliant on two types of thermosets that undergo irreversible crosslinking via ionizing radiation‐induced polymerization, the polymer's structure and characteristics being tailored using specific dose rates, doses, linear energy transfer and monomers ratio, in order to achieve the established performance requirements. Here, we demonstrate a covalently bonded 3D hybrid diepoxy‐triacrylic polymer that is chemically and dimensionally stable, intending to use it as a consolidant of highly degraded wooden artifacts in order to mitigate oxygen inhibition from radical chain reactions, to increase chemical and thermal stability, as well as to obtain a stiffer consolidated artifact, therefore more resistant to deformation. Various types of analytical techniques such as Attenuated Total Reflectance Fourier Transform Infrared Spectroscopy, Mass Spectrometry or Thermal analysis were performed in order to support our strategy and predictions regarding the synergistic effect given by gamma irradiation‐driven crosslinking through simultaneous cationic and radical chain growth polymerization reaction mechanisms. We achieved a homogenous polymeric formulation and wood‐polymer composite materials with high modulus of elasticity, therefore providing up to a twofold increase in Young's modulus in the consolidated wood, a good chemical resistance to various solvents and outstanding thermal resistance up to 381°C. Consequently, the consolidation methodology, as well as mechanical testing, analytical and morphological characterization of the resulted composite will be discussed. Apart from consolidating cultural heritage wooden artifacts, this synthetic route and impregnation methodology provide opportunities for wood‐polymer composites in a wealth of applications as reinforced wood‐based materials.

Physics-constrained multi-objective bayesian optimization to accelerate 3d printing of thermoplastics

The printing outcome of vat photopolymerization (VPP) of thermoplastics largely depends on physicochemical properties of monomers and their compositions in resins, which also greatly determine the material properties, e.g., tensile strength (σT) and toughness (UT)and phase transition temperature (Tg). A methodology for optimizing the resin formulation is of paramount importance in realizing highly printable thermoplastics with balanced σT/UT and target Tg while remaining largely underexplored. Herein, we introduce a multi-objective Bayesian optimization (MOBO) algorithm under two physics informed constraints (printability and Tg) to optimize two conflicting properties: σT and UT. The two constraints are formulated as two machine learning (ML) models, which are trained with weight ratios of the six monomers and physics informed (PI) descriptors derived from their physiochemical parameters. Dimensional reduction analysis reveals that the algorithm avoids recommendation of the monomer ratios that do not pass the two constraints. The printing failure rate is reduced from 16% in the background experiments to 3% in the recommended experiments. Within only 36 iterations (72 samples), the MOBO algorithm successfully identifies five sets of ratios leading to Pareto optimal of σT and UT. Due to the constraint in Tg they show appropriate Tg for shape memory application. The partial dependence analysis indicates that σT and UT depend on both the ratios and physiochemical features of the monomers. These results underscore capability of such a smart decision-making algorithm—with constraints that are not fully understood but can be informed by prior knowledge—in planning the experiments from the vast design space, thus holding a great promise for broader applications in materials design and manufacturing.

Comparison of ddRADseq and EUChip60K SNP genotyping systems for population genetics and genomic selection in Eucalyptus dunnii (Maiden).

Eucalyptus dunnii is one of the most important Eucalyptus species for short-fiber pulp production in regions where other species of the genus are affected by poor soil and climatic conditions. In this context, E. dunnii holds promise as a resource to address and adapt to the challenges of climate change. Despite its rapid growth and favorable wood properties for solid wood products, the advancement of its improvement remains in its early stages. In this work, we evaluated the performance of two single nucleotide polymorphism, (SNP), genotyping methods for population genetics analysis and Genomic Selection in E. dunnii. Double digest restriction-site associated DNA sequencing (ddRADseq) was compared with the EUChip60K array in 308 individuals from a provenance-progeny trial. The compared SNP set included 8,011 and 19,008 informative SNPs distributed along the 11 chromosomes, respectively. Although the two datasets differed in the percentage of missing data, genome coverage, minor allele frequency and estimated genetic diversity parameters, they revealed a similar genetic structure, showing two subpopulations with little differentiation between them, and low linkage disequilibrium. GS analyses were performed for eleven traits using Genomic Best Linear Unbiased Prediction (GBLUP) and a conventional pedigree-based model (ABLUP). Regardless of the SNP dataset, the predictive ability (PA) of GBLUP was better than that of ABLUP for six traits (Cellulose content, Total and Ethanolic extractives, Total and Klason lignin content and Syringyl and Guaiacyl lignin monomer ratio). When contrasting the SNP datasets used to estimate PAs, the GBLUP-EUChip60K model gave higher and significant PA values for six traits, meanwhile, the values estimated using ddRADseq gave higher values for three other traits. The PAs correlated positively with narrow sense heritabilities, with the highest correlations shown by the ABLUP and GBLUP-EUChip60K. The two genotyping methods, ddRADseq and EUChip60K, are generally comparable for population genetics and genomic prediction, demonstrating the utility of the former when subjected to rigorous SNP filtering. The results of this study provide a basis for future whole-genome studies using ddRADseq in non-model forest species for which SNP arrays have not yet been developed.

Aerosolization of poly(sulfobetaine) microparticles that encapsulate therapeutic antibodies

Pulmonary delivery of protein therapeutics poses significant challenges that have not been well addressed in the research literature or practice. In fact, there is currently only one commercial protein therapeutic that is delivered through aerosolization and inhalation. In this study, we propose a drug delivery strategy that enables a high-concentration dosage for the pulmonary delivery of antibodies as an aerosolizable solid powder with desired stability. We utilized zwitterionic polymers for their promising properties as drug delivery vehicles and synthesized swellable, biodegradable poly(sulfo-betaine) (pSB) microparticles. The microparticles were loaded with Immunoglobulin G (IgG) as a model antibody. We quantified the microparticle size and morphology, and the particles were found to have an average diameter of 1.6 μm, falling within the optimal range (~1–5 μm) for pulmonary drug delivery. In addition, we quantified the impact of the crosslinker to monomer ratio on particle morphology and drug loading capacity. The results showed that there is a trade-off between desired morphology and drug loading capacity as the crosslinker density increases. In addition, the particles were aerosolized, and our data indicated that the particles remained intact and retained their initial morphology and size after aerosolization. The combination of morphology, particle size, antibody loading capacity, low cytotoxicity, and ease of aerosolization support the potential use of these particles for pulmonary delivery of protein therapeutics.

Synthesis of poly N-aryl piperidinium membrane and ionomer for anion exchange membrane fuel cell applications

Ether free backbones have recently attracted widespread attention in anion exchange membrane fuel cells (AEMFCs). Here we report the synthesis of two poly N-aryl piperidinium (PNAP) membranes from their monomers by the polycondensation method using trifluoromethanesulfonic acid as a catalyst. Density functional theory identifies the chemical reaction, and the radial distribution function represents the interactions between a water molecule and a functional group of PNAP membranes. The performance of the anion exchange membrane can be enhanced by varying the monomer ratios of PNAP. An optimized PNAP-2 membrane exhibits a hydroxide conductivity of 183 mS cm−1 at 90 °C and PNAP-2 ionomers with Pt/C catalysts display a greater half-wave potential (E1/2) of 0.81 V and a lower Tafel value of 65 mV dec−1. In fuel cell tests, a PNAP-2 ionomer alongside a 60% platinum-on-carbon (Pt/C) membrane electrode assembly achieved a peak power density of 2.07 W cm−2. The PNAP-2 remained stable for more than 230 h at a constant current density of 0.3 A cm−2. PNAP-2 also displays exceptional resistance to alkaline conditions, lasting for more than 1000 h in both 1 M and 5 M NaOH solutions at 60 °C.

Modulated synthesis of stoichiometric and sub-stoichiometric two-dimensional covalent organic frameworks for enhanced ethylene purification

Controlled synthesis of two-dimensional covalent organic frameworks (2D COFs), including stoichiometric and sub-stoichiometric variations, is a topic of growing interest due to its potential in gas separation applications. In this study, we successfully synthesized three distinct 2D COFs by carefully adjusting solvent compositions and monomer ratios during the synthesis of [4 + 4] type COFs. These included a stoichiometric [4 + 4] type COF and two sub-stoichiometric [4 + 2] type COFs, featuring unreacted amino or formyl groups. The resulting COFs exhibit different gas adsorption and separation properties. Specifically, sub-stoichiometric COF-DA with residual amino groups shows comparable adsorption capacity for C2H2, C2H4, and CO2 to stoichiometric COF-DAPy. In contrast, sub-stoichiometric COF-Py with residual formyl groups displays enhanced adsorption selectivity for C2H2/C2H4 and C2H2/CO2 separation, with the C2H2/C2H4 selectivity being the highest among reported COFs, attributed to increased pore polarity resulting from the presence of formyl groups. This study not only offers an additional example of sub-stoichiometric COF synthesis but also advocates for further exploration of sub-stoichiometric COF materials, particularly in the field of gas adsorption and separation.

Stretchable, stable, and structural color reversible enabled by mesoscopic regulation and design for flexible photonic crystal mechanical sensors

This paper reports a flexible mechanical sensor developed by combining an opal photonic crystal and a flexible medium through UV curing technology. Under the action of external force, the deformation of the flexible medium causes the change of the photonic crystal lattice constant, which leads to the displacement of the reflection peaks, thus realizing the detection of the deformation of the film. The flexible medium is mixed by photoinitiators and polymer monomers, and its mechanical properties are directly related to the mass fraction of photoinitiators and polymer monomers. The results show that the film can reach a maximum strain of about 180% when the mass fraction of photoinitiator is 3% and the volume ratio of the polymer functional monomers is 8:2. In addition, for the responsiveness test of the sensor under tensile, the results show that at 0%, 26%, and 78% of tensile strain, its structural color is blue-shifted sequentially, and its spectral peaks are 668 nm, 535 nm, and 488 nm, respectively. Finally, the sensor is applied to the detection of acoustic waves in air, and it is found that its spectral response peaks can be obtained for acoustic waves of different frequencies (250–650 Hz), and a spectral peak at 500 Hz. This flexible photon sensor has the potential to match the acoustic resistance of water. It will greatly expand the response research of ocean exploration in the low frequency range.

Nitroxide-Mediated Controlled Radical Copolymerization of α-Trifluoromethylstyrenes with Styrenes.

Fluorinated polymers are important materials in everyday life; however, most monomers of widely used fluoropolymers are gaseous, and their polymerization is difficult in an ordinary laboratory. Therefore, partially fluorinated polymers have recently been reported. As an easy-to-handle fluorine-containing monomer, α-trifluoromethylstyrene (TFMST) can be used to produce partially fluorinated polymers with trifluoromethyl groups in the main chain; however, TFMST does not homopolymerize, and there are limited reports on its copolymerization with styrene (ST). In this study, we applied the controlled radical polymerization method, which is effective for the polymerization of ST, to the copolymerization of TFMST and ST. We also showed that nitroxide-mediated polymerization is effective. The content ratio of TFMST in the TFMST-ST copolymer can be controlled between 10% and 40% by changing its monomer ratio. Additionally, the polymerization of TFMST and ST with substituents was performed to increase structural variations. The thermal stability as well as water and oil repellency of the synthesized polymers with different composition ratios and substituents were also evaluated.

Droplet photopolymerization as new strategy for the rapid preparation of hydrogel beads for malachite green removal

Green and efficient preparation of hydrogel beads remains a great challenge. In this study, the hydrogel beads (AGSP) were directly prepared within 10 s from drop-out to drop-down of the droplets in paraffin oil under green LED irradiation using sodium acrylate and acrylamide as the functional monomers, methacrylated carboxymethyl chitosan (CMCSG) as a crosslinker based on carboxymethyl chitosan and poly(ethylene glycol) as porogen. Molar ratios of monomers were modified to optimize the adsorption of hydrogel beads, and the optimal adsorption capacity for malachite green (MG) was 503.33 mg·g−1. Scanning electron microscopy (SEM), thermogravimetric analysis (TGA), X-ray photoelectron spectroscopy (XPS), and fourier transform infrared (FTIR) spectroscopy were used to determine the structural characteristics of the hydrogel beads. The removal of MG by AGSP was investigated and the adsorption kinetics and isotherms were calculated to understand the adsorption mechanism. Our research provides a green and efficient technique for preparing hydrogel beads for dye removal.

Preparation and Characterization of Bilayer Polymer-Dispersed Liquid Crystals Doped with Gd2O3 Nanoparticles and Rhodamine B Base Fluorescent Dye.

Using the polymerization-induced phase separation (PIPS) method, bilayer polymer-dispersed liquid crystal (PDLC) films with a PDLC-PVA-PDLC structure were prepared in this work. It was found that all PDLC performance indexes were affected by polymer mesh size after comparing the microscopic morphology and electro-optical properties of samples with different monomer ratios. Gd2O3 nanoparticles and rhodamine B base fluorescent dyes introduced into the bilayer PDLC optimized the samples' electro-optical properties and developed new functionalities. In addition, the bilayer PDLC doped with Gd2O3 and rhodamine B base held excellent progressive driving functions as well as stable durability properties. Samples doped with Gd2O3 nanoparticles and rhodamine B base also produced excellent anti-counterfeiting effects under UV irradiation at different angles, further exploiting the application potential of PDLC.

Generation of G51D and 3D mice reveals decreased α-synuclein tetramer-monomer ratios promote Parkinson’s disease phenotypes

Mutations in the α-Synuclein (αS) gene promote αS monomer aggregation that causes neurodegeneration in familial Parkinson’s disease (fPD). However, most mouse models expressing single-mutant αS transgenes develop neuronal aggregates very slowly, and few have dopaminergic cell loss, both key characteristics of PD. To accelerate neurotoxic aggregation, we previously generated fPD αS E46K mutant mice with rationally designed triple mutations based on the α-helical repeat motif structure of αS (fPD E46K→3 K). The 3 K variant increased αS membrane association and decreased the physiological tetramer:monomer ratio, causing lipid- and vesicle-rich inclusions and robust tremor-predominant, L-DOPA responsive PD-like phenotypes. Here, we applied an analogous approach to the G51D fPD mutation and its rational amplification (G51D → 3D) to generate mutant mice. In contrast to 3 K mice, G51D and 3D mice accumulate monomers almost exclusively in the cytosol while also showing decreased αS tetramer:monomer ratios. Both 1D and 3D mutant mice gradually accumulate insoluble, higher-molecular weight αS oligomers. Round αS neuronal deposits at 12 mos immunolabel for ubiquitin and pSer129 αS, with limited proteinase K resistance. Both 1D and 3D mice undergo loss of striatal TH+ fibers and midbrain dopaminergic neurons by 12 mos and a bradykinesia responsive to L-DOPA. The 3D αS mice have decreased tetramer:monomer equilibria and recapitulate major features of PD. These fPD G51D and 3D mutant mice should be useful models to study neuronal αS-toxicity associated with bradykinetic motor phenotypes.

Low-cost electrochemical biosensor based on a multi-walled carbon nanotube-doped molecularly imprinted polymer for uric acid detection

Uric acid is a naturally occurring antioxidant that must be maintained in the human body at 1.49–4.46 mM to prevent hyperuricemia, which may lead in the formation of monosodium urate (MSU) and Lesch–Nyhan syndrome. The objective of this research is to examine molecularly imprinted polymers (MIP)-based non-enzymatic electrochemical sensors that simulate the biological mechanism of uricase oxidase. As an affordable working electrode, commercial pencil graphite electrode (PGE) was modified with multi-walled carbon nanotubes (MWCNTs) and polypyrrole. With a 1:10 uric acid to monomer ratio, 20 cycles of polymerization, 100 mV s−1 of polymerization rate, and 30 cycles of template removal, the optimum MIP was obtained. By employing differential pulse voltammetry (DPV) to detect the presence of uric acid over the range of 0.22–3.5 mM, the limit of detection (LOD) was determined to be 0.76 mM, with a sensitivity of 97.459 µA µM−1 cm−2. This sensor demonstrated good repeatability and reproducibility, with relative standard deviation percentage (%RSD) of 3.43 % (n = 10) and 5.37 % (n = 3), respectively, which maintains a performance stability of 71 % after 19 days of use. This sensor also detected uric acid with good selectivity, even in the presence of interfering molecules including K+, Na+, sarcosine, citric acid, ascorbic acid, glucose, and dopamine.

Designing an optimised formulation for in situ emulsion polymerization: printing ink production by response surface methodology

Purpose Toner is a crucial dry colorant composite used in printing based on the electrophotographic process. The quality of printed images is greatly influenced by the toner production method and material formulation. Chemically in situ polymerization methods are currently preferred. This paper aims to optimize the characteristics of a composite produced through emulsion polymerization using common raw materials for electrophotographic toner production. Design/methodology/approach Emulsion polymerization provides the possibility to optimize the physical and color properties of the final products. Response surface methodology (RSM) was used to optimize variables affecting particle size (PS), PS distribution (PSD), glass transition temperature (Tg°C), color properties (ΔE) and monomer conversion. Box–Behnken experimental design with three levels of styrene and butyl acrylate monomer ratios, carbon black pigment and sodium dodecyl sulfate surfactant was used for RSM optimization. Additionally, thermogravimetric analysis and surface morphology of composite particles were examined. Findings The results indicated that colorants with small PS, narrow PSDs, spherical shape morphology, acceptable thermal and color properties and a high percentage of conversion could be easily prepared by optimization of material parameters in this method. The anticipated outcome of the present inquiry holds promise as a guiding beacon toward the realization of electrographic toner of superior quality and exceptional efficacy, a vital factor for streamlined mass production. Originality/value To the best of the authors’ knowledge, for the first time, material parameters were evaluated to determine their impact on the characteristics of emulsion polymerized toner composites.

An in situ encapsulation strategy for enhancing the stability of hydrogels in both air and water through surface-confined copolymerization

Air-drying and water-swelling are significant limitations of conventional hydrogels, hindering their potential applications. In this study, we present a facile, versatile and in situ encapsulation strategy aimed at overcoming these drawbacks and enhancing the stability of hydrogels in both air and water. Our method involves creating a flexible and hydrophobic polymer coating through surface-confined copolymerization of triethoxyvinylsilane (VETS) and 2, 2, 3, 4, 4, 4-hexafluorobutyl methacrylate (HFMA), along with the infusion of a hydrophobic oil layer through hydrophobic interactions. By adjusting the monomer ratio, polymerization time, and oil viscosity, we successfully anchored a flexible double-hydrophobic-coating to the hydrogel surface without compromising its mechanical properties. This double-layer-coating acts as an effective barrier, significantly reducing water evaporation within the hydrogel and preventing water diffusion and penetration from the external environment. Remarkably, the encapsulated hydrogel retains over 75.0 % of its weight after a 7-day air-drying test and exhibits non-swelling behavior in diverse aqueous environments for 150 days. Moreover, our strategy is applicable to various hydrogel types and shapes, demonstrating its universality in enhancing resistance against both drying and swelling. Therefore, the proposed approach offers valuable insights into the surface functionalization of hydrogel and broadens the application of next-generation hydrogels in real-world settings, spanning wet and dry environments.

Development and Fabrication of a Molecularly Imprinted Polymer-Based Electroanalytical Sensor for the Determination of Acyclovir.

Acyclovir (ACV), a synthetic nucleoside derivative of purine, is one of the most potent antiviral medications recommended in the specific management of varicella-zoster and herpes simplex viruses. The molecularly imprinted polymer (MIP) was utilized to create an effective and specific electrochemical sensor using a straightforward photopolymerization process to determine ACV. The polymeric thin coating was developed using the template molecule ACV, a functional monomer acrylamide, a basic monomer 2-hydroxyethyl methacrylate, a cross-linker ethylene glycol dimethacrylate, and a photoinitiator 2-hydroxy-2-methyl propiophenone on the exterior of the glassy carbon electrode (GCE). Scanning electron microscopy, attenuated total reflectance-Fourier transform infrared spectroscopy, electrochemical impedance spectroscopy, and cyclic voltammetry were employed for the purpose of characterizing the constructed sensor (AM-ACV@MIP/GCE). Differential pulse voltammetry and a 5 mM ferrocyanide/ferricyanide ([Fe(CN)6]3-/4-) redox reagent were used to detect the ACV binding to the specific cavities on MIP. The study involves density functional theory (DFT) calculations, which were conducted to investigate template-functional monomer interactions thoroughly, calculate template-functional monomer interaction energies, and determine the optimal template/functional monomer ratio. DFT calculations were performed using Becke's three-parameter hybrid functional with the Lee-Yang-Parr correlation functional (B3LYP) method and 6-31G(d,p) basis set. The sensor exhibits linear performance throughout the concentration region 1 × 10-11 to 1 × 10-10 M, and the limit of detection and limit of quantification were 7.15 × 10-13 M and 2.38 × 10-12 M, respectively. For the electrochemical study of ACV, the sensor demonstrated high accuracy, precision, robustness, and a short detection time. Furthermore, the developed electrochemical sensor exhibited exceptional recovery in tablet dosage form and commercial human blood samples, with recoveries of 99.40 and 100.44%, respectively. The findings showed that the AM-ACV@MIP/GCE sensor would effectively be used to directly assess pharmaceuticals from actual specimens and would particularly detect ACV compared to structurally similar pharmaceutical compounds.

Anisotropic Magnetic Polymeric Particles with a Controllable Structure via Seeded Emulsion Polymerization.

Magnetic polymer composites have been widely utilized in potential applications in material science, such as reduction of dyes, immunodiagnostics, biomedicals, and magnetically controllable photonic crystals owing to large surface areas, fast separation, and recyclable performance. In this work, anisotropic magnetic particles were prepared by seeded emulsion polymerization, with morphologies of "Fe3O4-shell", "hemisphere-like", "raspberry-like", "multiple lobes-like", and "sandwich-like". Poly(styrene/divinylbenzene/mono-2-(methacryloxy)ethyl succinate)@ Fe3O4 (P(St/DVB/MMES)@Fe3O4) were the seed microspheres, and P(St/DVB/MMES)@Fe3O4@polymer particles are achieved by seeded emulsion polymerizations. The morphology of the particles depends on polymerization conditions (monomer ratios and surfactant), particle properties, and so on. Then, the minimum surface free energy change principles were used to predict the equilibrium morphologies of the magnetic polymer composites. Through theory, the model gives the correct tendency and good agreement with the equilibrium morphology which was in tandem with TEM results. Lastly, after in situ surface deposition of Ag nanoparticles, magnetic composite particles with sandwich-like morphology were applied for the catalytic degradation of 4-nitrophenol (4-NP) reacting with NaBH4. The apparent rate coefficient is 0.0069 s-1, and it can keep mainly about 80% efficiency in catalysis after five cycles.

Effect of acrylic acid on water‐whitening resistance of polyacrylate latex films and its mechanism

AbstractTwo groups of polyacrylate latexes with higher (21 ~ 35 °C) or lower (−33 ~ −43 °C) glass transition temperatures (Tg) were prepared by adjusting the monomer ratio of butyl acrylate (BA) and styrene (St), and the effect of acrylic acid (AA) on water‐whitening resistance of these latex films was investigated. It was found that the water‐whitening resistance of the two groups of latex films was different. With the increase of AA content, the water whitening resistance of the latex films with higher Tg continued to improve, while that of the latex films with lower Tg increased first and then decreased. A series of characterizations, such as light transmittance, water whitening, water absorption, static water contact angle, surface morphology, and optical microscope test of the latex film, and so forth, showed that the reason for this difference was that under higher AA content (≥5%), compared with the polyacrylate latex films with lower Tg, the latex films with higher Tg could reach the saturation state of water absorption quickly, and water in these latex films exhibited continuous and large area distribution, rather than formation of many so‐called micro‐ or nano‐scale water sacs that can scatter light as found in the latex films with lower Tg.

Synthesis, Characterization, and Evaluation of the Adsorption Behavior of Cellulose-Graft-Poly(Acrylonitrile-co-Acrylic Acid) and Cellulose-Graft-Poly(Acrylonitrile-co-Styrene) towards Ni(II) and Cu(II) Heavy Metals.

In this study, the synthesis and characterization of grafted cellulose fiber with binary monomers mixture obtained using a KMnO4/citric acid redox initiator were investigated. Acrylonitrile (AN) was graft copolymerized with acrylic acid (AA) and styrene (Sty) at different monomer ratios with evaluating percent graft yield (GY%). Cell-g-P(AN-co-AA) and Cell-g-P(AN-co-Sty) were characterized by SEM, FT-IR, 13C CP MAS NMR, TGA, and XRD. An AN monomer was used as principle-acceptor monomer, and GY% increases with AN ratio up to 60% of total monomers mixture volume. The adsorption behaviors of Cell-g-P(AN-co-AA) and Cell-g-P(AN-co-Sty) were studied for the adsorption of Ni(II) and Cu(II) metal ions from aqueous solution. Optimal adsorption conditions were determined, including 8 h contact time, temperature of 30 °C, and pH 5.5. Cell-g-P(AN-co-AA) showed maximum adsorption capacity of 435.07 mg/g and 375.48 mg/g for Ni(II) and Cu(II), respectively, whereas Cell-g-P(AN-co-Sty) showed a maximum adsorption capacity of 379.2 mg/g and 349.68 mg/g for Ni(II) and Cu(II), respectively. Additionally, adsorption equilibrium isotherms were studied, and the results were consistent with the Langmuir model. The Langmuir model's high determinant coefficient (R2) predicted monolayer sorption of metal ions. Consequently, Cell-g-P(AN-co-AA) and Cell-g-P(AN-co-Sty) prepared by a KMnO4/citric acid initiator were found to be efficient adsorbents for heavy metals from wastewater as an affordable and adequate alternative.

Novel porous organic polymer supported chloramphenicol base derivatives: A highly enantioselective, recyclable heterogeneous organocatalyst for asymmetric desymmetrization reaction

A series of porous organic polymer (POP) supported chloramphenicol base (ANP) derived catalysts are designed and prepared. A deep study of the polymerization condition, including reaction temperature, the ratio of monomers and the option of polymetric position on ANP scaffold was conducted. The best catalyst, poly-Ia, performs high stereoselectivity and catalytic activity (up to 98% yield and 99% ee) in asymmetric alcoholysis of meso-cyclic anhydride with the possibility of high recyclability (at least 10 times). More importantly, poly-Ia even obtains higher enantioselectivity compared to its homogeneous monomer, which overcomes the common drawback of heterogeneous organocatalysts, for instance, lower selectivity and diminished reactivity.