Outgassing analysis of molecular glass photoresists under EUV irradiation

A device was designed and assembled to analyze the outgassing of molecular glass(MG)photoresists under extreme ultraviolet(EUV)exposure.The outgassing of the photoresists with different components and different concentrations of tert-butoxycarbonyl(t-Boc),photo-generated acid(PAG),and acid quencher was systematically investigated.Based on experiments,some solutions for reducing the outgassing of MG photoresists were proposed.     

Study on the synthesis and properties of an environmentally friendly water treatment agent

The long-term application of phosphorus-containing or nitrogen-containing water treatment agents can easily lead to the eutrophication of water bodies. Here, a random copolymer IA/SMAS was synthesized by itaconic acid (IA) and sodium methacrylate sulfonate (SMAS) monomer by the aqueous polymerization method. The optimal synthesis conditions were as follows: a raw material mass ratio (IA:SMAS) of 2:1, a temperature of 95 °C and a reaction time of 6 h. In addition, ammonium persulfate and isopropanol were both added at 5 % of the total raw material mass. The copolymer IA/SMAS was characterized by infrared spectroscopy (IR), elemental analysis, nuclear magnetic resonance (NMR), field emission scanning electron microscopy (FESEM), and EDS. Its molecular weight and distribution were analyzed by gel chromatography (GPC). Static methods were used to evaluate copolymers and their performance in synergy with electrostatic fields. The scale inhibition mechanism of the copolymer and its synergistic effect with electrostatic field were also studied by a scanning electron microscope (SEM) and X-ray diffraction (XRD). The results show that the copolymer had excellent scale inhibition performance for calcium carbonate and good dispersion effect on iron oxide. The addition of the electrostatic field improved the scale inhibition performance of IA/SMAS copolymer by 16 %. Thus, the copolymer is a phosphorus-free and nitrogen-free water treatment agent that achieves excellent performance and can significantly disrupt the surface morphology and crystalline structures of crystals.     

Towards environmentally and human friendly insect pest control technologies: photosensitization of leafminer flies Liriomyza bryoniae

Development of new, ecologically safe technologies to control insect pest populations is of great importance. Photoactive compounds usually used for photosensitization might be effective as pesticide agents, with low impact on the environment, being non-toxic and not mutagenic. Phosensitizer accumulates within the insect body and, following exposure to visible light, induces lethal photochemical reactions and death. The aim of this study is to evaluate the possible usage of several photosensitizers (acridine orange, aminolevulinic acid, hematoporphyrin dimethyl ether, methylene blue) as photopesticides to control population of polyphagous plant pest Liriomyza bryoniae (Kaltenbach, 1858) (Diptera, Agromyzidae). Fluorescence measurements of intact cooled insects indicate that insect feeding with bait containing HPde and sugar induces remarkable accumulation of this compound in the body of insect. This accumulation is strongly dependent on sex and feeding duration. The highest HPde amount in the body of insect was detected 16 h after feeding, whereas no significant photosensitizer amount was detected in the same insect following 48 h. Following irradiation with visible light results in fast death of L. bryoniae. Of importance to note that survival of insects after feeding and irradiation depends on sex: female insect died much faster than males.     

An environmentally friendly multicommutated alternative to the reference method for anionic surfactant determination in water

It has been developed a fully mechanized procedure for the spectrophotometric determination of anionic surfactants in water expressed in terms of SDS concentration. The reference method, based on the reaction of SDS with methylene blue (MB) followed by extraction in chloroform, was mechanized in order to reduce the consumption of organic solvents. The system was based on the multicommutation approach and provided a 35 times reduction of the waste production without sacrificing the figures of merit of the method in terms of sensitivity and repeatability, for a dynamic linear range from 0.2 to 1.7 mg l⁻¹. Results obtained for washing water samples were comparable with those obtained using the reference method and no significant differences, at 95% confidence level, were observed. Other useful characteristics are a solvent consumption of 0.7 ml per determination, a sampling throughput of 40 determinations per hour, a relative standard deviation of 5.9% (n = 10) for a sample containing 2 × 10⁻⁶ mol l⁻¹ (576 μg l⁻¹) surfactant and a limit of detection of 6.1 × 10⁻⁹ mol l⁻¹ (1.7 μg l⁻¹).     

Enantiospecific synthesis of isomers of AES, a new environmentally friendly chelating agent

Three four-step enantiospecific syntheses of different diastereomers of AES, a new biodegradable chelating agent, are described. The stereocenters in each of the isomers are accessible from l- and d-malic and aspartic acids.     

Validated, non-destructive and environmentally friendly determination of cocaine in euro bank notes

A non-destructive, fast and environmentally friendly procedure has been developed for cocaine determination in euro bank notes. Cocaine was extracted with 15 ml methanol by vortex agitation during 5 min. The extract was evaporated and reconstituted in 0.5 ml methanol. GC-MS-MS analysis was performed using as precursor ion m/z 182.2, with an excitation energy voltage of 1.60 eV, being the product ions measured m/z 150.2 and 82.0. A limit of detection of 0.15 ng per note and a repeatability of 6%, established from the relative standard deviation, of a 1 ng ml(-1) level, were achieved. Recoveries of 101+/-2 and 98+/-3% were obtained for samples spiked with 100 and 10 microg respectively. Results show that all the euro bank notes measured (16 samples) were contaminated with cocaine in the range between 1.25 and 889 microg. Two different contamination levels, high level (150-889 microg) and low one (1.25-77 microg) were found and it could be related with the direct or indirect contact with the drug.     

A novel, environmentally friendly dispersive liquid-liquid microextraction procedure for the determination of copper

A novel, simple and environmentally friendly procedure for copper determination has been developed. The method is based on the formation of an ion associate of Cu(I) with 1,3,3-trimethyl-2-[5-(1,3,3-trimethyl-1,3-dihydroindol-2-ylidene)-penta-1,3-dienyl]-3H-indolium (DIDC) in the presence of chloride ions as ligand, followed by dispersive liquid-liquid microextraction (DLLME) of the formed ion associate into organic phase and UV-Vis spectrophotometric detection. The following experimental conditions were used: pH 3, 0.24 mol L^− 1 chloride ions, 0.06 mmol L^− 1 DIDC. The effect of the nature of the extraction solvent, auxiliary solvent and disperser solvent used was studied. A mixture of amyl acetate, tetrachloromethane, and methanol in a 1:1:3 v/v/v ratio was selected for the DLLME procedure. The absorbance of the coloured extracts at 640 nm wavelength obeys Beer's law in the range 0.020-0.090 mg L^− 1 of Cu. The limit of detection calculated from a blank test (n = 10) based on 3s is 0.005 mg L^− 1 of Cu. The developed procedure was applied to the analysis of water samples. The suggested DLLME is compared with two procedures previously reported from our laboratory based on (1) conventional liquid-liquid extraction, and (2) sequential injection extraction performed in a dual-valve sequential injection system. The advantages and disadvantages of each method are discussed.     

Low-cost,environmentally friendly and high-performance cellulose-based triboelectric nanogenerator for self-powered human motion monitoring

Cellulose-based triboelectric nanogenerators (TENGs) can provide power for various monitoring devices and are environmentally friendly and sustainable. Chemical functional modification is a common method to improve the electrical output performance of cellulose-based TENGs. In this work, an environmentally friendly high-performance triboelectric nanogenerator based on a polydopamine/cellulose nanofibril (PDA/CNF) composite membrane and fluorinated ethylene propylene was developed. Dopamine generates polydopamine nanoparticles through oxidative self-polymerization and adheres to the surface of nanofibers. The synergistic effect of amino group introduction and membrane surface microstructure effectively enhanced the output performance of TENGs to a certain extent. The effects of PDA content, CNF composite film thickness and different working conditions on the electrical output were systematically investigated. The optimized PDA/CNF-TENGs exhibited an enhanced electrical output performance with voltage, current, and power density values of ≈205 V, ≈20 µA, and ≈48.75 μW·cm^?2, respectively. The PDA/CNF-TENGs exhibited stable and identifiable signals when used as a self-powered sensor for human motion monitoring, showing the potential prospects of cellulose materials for TENGS and other electronic applications.

Graphical abstract

     

Demetalization of oils resulting from recycled tires by liquid-liquid extraction using modified superheated water An environmentally friendly approach

An approach based on continuous pressurized liquid-liquid extraction with 20% HNO₃/1 M KCl/10⁻³ M EDTA as extractant has been developed for the extraction of metals from the oil resulting from recycled tires. A multivariate optimization of the main variables affecting the extraction process has been performed. The method has been applied to three oil samples with different contents in V, Ni, Zn, Fe and Cu. The target metals have been determined in both untreated and treated oil by flame atomic absorption spectrometry (FAAS) in order to obtain the extraction efficiency. Under the optimum conditions, recoveries higher than 90% have been obtained with a repeatability and within-laboratory reproducibility, expressed as relative standard deviations, ranging from 2.75 to 6.91 and 2.97 to 8.16%, respectively. For applications where the demetalization does not require being complete, a study of the demetalization degree achieved depending on the extraction temperature and extractant composition has also been performed. This study provides useful data about the cheapest working conditions to be used in order to obtain a given demetalization level.     

A multisite molecular mechanism for Baeyer-Villiger oxidations on solid catalysts using environmentally friendly H2O2 as oxidant

The molecular mechanism of the Baeyer-Villiger oxidation of cyclohexanone with hydrogen peroxide catalyzed by the Sn-beta zeolite has been investigated by combining molecular mechanics, quantum-chemical calculations, spectroscopic, and kinetic techniques. A theoretical study of the location of Sn in zeolite beta was performed by using atomistic force-field techniques to simulate the local environment of the active site. An interatomic potential for Sn/Si zeolites, which allows the simulation of zeolites containing Sn in a tetrahedral environment, has been developed by fitting it to the experimental properties of quartz and SnO2(rutile). The tin active site has been modeled by means of a Sn(OSiH3)3OH cluster, which includes a defect in the framework that provides the flexibility necessary for the interaction between the adsorbates and the Lewis acid center. Two possible reaction pathways have been considered in the computational study, one of them involving the activation of the cyclohexanone carbonyl group by Sn (1) and the other one involving hydrogen peroxide being activated through the formation of a tin-hydroperoxo intermediate (2). Both the quantum-chemical results and the kinetic study indicate that the reaction follows mechanism 1, and that the catalyst active site consists of two centers: the Lewis acid Sn atom to which cyclohexanone has to coordinate, and the oxygen atom of the Sn-OH group that interacts with H2O2 forming a hydrogen bond.     

Innovation in a chemical reaction process using a supercritical water microreaction system: environmentally friendly production of epsilon-caprolactam

Our microreaction system using supercritical water solutions achieves nearly 100% yield and 100% selectivity for epsilon-caprolactam production at reaction times shorter than 1 s.     

The first zinc-promoted,environmentally friendly,and highly efficient acetoxyallylation of aldehydes in aqueous ammonium chloride

An exceptionally mild acetoxyallylation of aldehydes in water promoted by zinc is reported, using 3-bromo-1-acetoxyprop-1-ene as starting material; simple diastereoselectivity mainly depends on the nature of the aldehyde.     

An environmentally friendly,cost effective synthesis of quinoxalines: the influence of microwave reaction conditions

A convenient, environmentally friendly and novel synthesis of quinoxalines using silica gel as the catalyst is described. The choice of microwave conditions has been shown to have a substantial impact on the reaction outcome with closed-vessel microwave irradiation resulting in the formation of quinoxalines in high yields and short reaction times. Preliminary mechanistic investigations have indicated that a slight build-up in pressure has a major impact on the reaction outcome.     

Heteropolyacid@creatin-halloysite clay: an environmentally friendly,reusable and heterogeneous catalyst for the synthesis of benzopyranopyrimidines

Research on Chemical Intermediates - A novel hybrid catalyst has been designed and synthesized based on the incorporation of heteropolyacid into creatin-functionalized halloysite clay. The catalyst...     

Pentafluorophenylammonium triflate as an efficient, environmentally friendly and novel organocatalyst for synthesis of bis-indolyl methane derivatives

A simple, inexpensive, environmentally friendly and efficient route for the synthesis of bis-indolyl methane derivatives by the reaction of indole or N-methyl indole with aldehydes using pentafluorophenylammonium triflate (PFPAT) as a catalyst is described. PFPAT organocatalyst is air-stable, cost-effective, easy to handle, and easily removed from the reaction mixtures.     

Synthesis of environmentally friendly,magnetic acid-type calix[4]arene catalyst for obtaining Biginelli adducts

An immobilized p-sulfonic acid calix[4]arene was synthesized on the surface of silica-coated Fe₃O₄ nanoparticles. Due to the combination of the magnetic recovery and the acid properties, it acted as a robust, safe and environmentally friendly catalyst for the one-pot synthesis of Biginelli adducts under microwave irradiation and solvent-free conditions. A series of Biginelli adducts were obtained in moderate to excellent yields, and most importantly, the catalyst could be easily recovered by an external magnet and reused five times without significant loss of catalytic activity (ca. 80% yield for all reuses using 0.64 mol% of the catalyst).     

Indion 190 resin: efficient,environmentally friendly,and reusable catalyst for synthesis of benzimidazoles,benzoxazoles, and benzothiazoles

Abstract

An efficient and mild protocol has been developed for the preparation of benzimidazoles, benzoxazoles, and benzothiazoles from reactions of aldehydes with o-substituted aminoaromatics in the presence of catalytic amount of Indion 190 resin. Short reaction time, ambient conditions, simple work-up procedure, high yield, easy availability, reusability, and use of an eco-friendly catalyst are some of the striking features of the present protocol.     

Preparation, characterization and electrochemical corrosion studies on environmentally friendly waterborne polyurethane/Na-MMT clay nanocomposite coatings

In this study, we present the first practical evaluation for the corrosion protection effect of waterborne polyurethane (WPU)/Na⁺-montmorillonite (Na⁺-MMT) clay nanocomposite coating. Typically, a series of waterborne polyurethane (WPU)/Na⁺-montmorillonite (Na⁺-MMT) clay nanocomposite materials have been successfully prepared by effectively dispersing the inorganic nanolayers of commercially purified Na⁺-MMT clay in WPU matrix through direct aqueous solution dispersion technique. First of all, WPU was prepared by polymerizing PCL, DMPA and H₁₂MDI, followed by characterized by nuclear magnetic resonance (¹H NMR), Fourier transform infrared (FTIR) and gel permeation chromatography (GPC). Subsequently, the as-prepared PU/Na⁺-MMT clay nanocomposite (Na⁺-PCN) materials were subsequently characterized by FTIR, X-ray diffraction (XRD) patterns and transmission electron microscopy (TEM).PCN materials in the form of coating at low Na⁺-MMT clay loading up to 3 wt% coated on the cold-rolled steel (CRS) coupons were found to exhibit superior corrosion protection effect over those of neat WPU based on a series of electrochemical measurements of corrosion potential, polarization resistance, corrosion current and impedance in 5 wt% aqueous NaCl electrolyte. Effects of the material composition on the gas permeability, thermal stability and optical clarity of neat WPU along with a series of Na⁺-PCN materials, in the form of coating and free-standing film, were also studies by gas permeability analyzer (GPA), thermogravimetric (TGA), differential scanning calorimetry (DSC) and ultraviolet UV-visible transmission spectroscopy, respectively. As control experiments, a series of PU/organo-MMT nanocomposite (denoted by organo-PCN) materials were also prepared for comparative studies.     

Benzyltriethylammonium dichloroiodate/sodium bicarbonate combination as an inexpensive, environmentally friendly, and mild iodinating reagent for anilines

[reaction: see text]. Monoiodinated anilines were prepared in good to excellent yields by the action of benzyltriethylammonium dichloroiodate on anilines in the presence of sodium bicarbonate and methanol. The iodinating reagent was prepared in an environmentally friendly fashion without the use of organic solvents.