Cellulose-derived raw materials towards advanced functional transparent papers.

Pulp and paper are gradually transforming from a traditional industry into a new green strategic industry. In parallel, cellulose-derived transparent paper is gaining ground for the development of advanced functional materials for light management with eco-friendly, high performance, and multifunctionality. This review focuses on methods and processes for the preparation of cellulose-derived transparent papers, highlighting the characterization of raw materials linked to responses to different properties, such as optical and mechanical properties. The applications in electronic devices, energy conversion and storage, and eco-friendly packaging are also highlighted with the objective to showcase the untapped potential of cellulose-derived transparent paper, challenging the prevailing notion that paper is merely a daily life product. Finally, the challenges and propose future directions for the development of cellulose-derived transparent paper are identified.

Orientation of internet use, government trust, and public environmental satisfaction an empirical study in Mainland China.

Public environmental satisfaction is related to the healthy living standard of human beings and sustainable development of an economic society. In the context of the continuous updating of Internet technologies, it is necessary to study the correlation between Internet use and public environmental satisfaction, but few studies have focused on the effect of the orientation of Internet use on public environmental satisfaction, and its mediating mechanisms. This study considered survey data from the China Social Survey 2019 which were conducted in a sample of 5,112 residents, SPSS 16.0 and ordinary least squares regression model was used to analyze the relationship between orientation of Internet use, government trust and public environmental satisfaction. The results showed politically-oriented Internet use was positively correlated with public environmental satisfaction, and entertainment-oriented Internet use did not correlate with public environmental satisfaction. Furthermore, government trust partially mediated the relation between politically-oriented Internet use and public environmental satisfaction. Several implication policies are suggested for improving public environmental satisfaction. This study takes into account individual initiative and government's control of information during Internet use, emphasizes the impact of different individual Internet use preferences on environmental satisfaction in the web environment with strong government control. By incorporating individual factors at the micro level and social factors at the macro level, this paper is in order to improve public environmental satisfaction.

Bride price and gender role in rural China.

Based on a qualitative analysis conducted in four provinces of rural China, this article sheds light into the adverse effects of bride price practice on women. Research has shown that the negative effect of the bride price practice on women is produced continuously rather than in a single step. The practice of bride price is a dynamic process, which involves the formation of three practical spaces, namely the physical space for negotiation, the public space for discussion, and the family space for allocation and use of bride price. In these three spaces, the interactive content of actions and language surrounding the bride price constructs women as an insider and an outsider; the approver and the performer; and family caregivers. This process continually awakens women's self-awareness but not beyond the scope of bride price, leading to their limited growth. This article examines how the increasing bride price in rural China influences women in the flow process, thus verifying whether high bride price can improve women's status.

Metal-organic frameworks-derived hierarchical Co3O4/CoNi-layered double oxides nanocages with the enhanced catalytic activity for toluene oxidation.

The development of active transition-metal oxide (TMO) catalysts for the abatement of volatile organic compounds (VOCs) remains a great challenge. Controllable synthesis of TMOs with specific morphology and suitable composition is a promising way for acquiring efficient oxidation catalysts. Herein, a series of hierarchical Co3O4/CoNi-layered double oxides (CoNi-LDO) nanocages covered by interlaced nanosheets were synthesized using a cobalt metal-organic framework (Co-MOF)-based strategy. The textural properties, morphology, surface chemical state, and reducibility of the CoNi-LDO catalysts were systematically characterized by various techniques. The catalytic activity toward toluene oxidation and the stability performance was investigated. Results demonstrated that the morphology, composition, and textual properties can be controlled by tuning the post-synthetic etching reaction conditions. Benefiting from the structural and compositional merits, as well as the superior low-temperature reducibility, the CoNi-LDO-1 catalyst (Ni/Co molar ratio was 0.39) with core-shell structure exhibited excellent activity toward toluene oxidation. Our work offers a new strategy for the design of high-performance oxidation catalysts for the abatement of VOCs.

Enhanced BiFeO3/Bi2Fe4O9/H2O2 heterogeneous system for sulfamethoxazole decontamination: System optimization and degradation pathways.

Sulfonamides as the major antibiotic have become emerging contaminants worldwide in aquatic environments. Herein, a heterogeneous Fenton-like oxidation driven by a novel BF-PMCs bismuth ferrites reported firstly for efficient degradation of sulfamethoxazole (SMX) in which the possible degradation pathways are thoroughly analyzed through identifying some of key intermediates (i.e., C8H11N3O4S, C4H4NO2, etc.) using liquid chromatography-mass spectrum (LC-MS), monitoring organic acids (i.e., acetic acid, pyruvic acid) and inorganic anions (i.e., sulfate, nitrate) using ion chromatography (IC), and detecting radical species (i.e., HO) using both chemical quenchers and fluorescence technique, simultaneously. The optimal operations in BF-PMCs/H2O2 system for SMX degradation are recommended at the conditions of initial pH ~4.5, 1.5 mg L-1 [SMX], 70 mM [H2O2], and BF-PMCs loading of 0.2 g L-1. The degradation rates (kinetic value of kapp) for SMX, azoxystrobin, bisphenol A, and 2,4-dichlorophenol are 9.5 × 10-3, 13.6 × 10-3, 7.3 × 10-3, and 5.9 × 10-3 min-1, respectively. Meanwhile, the degradation rates in BF-PMCs/H2O2 system for SMX degradation are slightly slower in the presence of inorganic anions (e.g., Cl-, NO3-) and NOM (e.g., humic acid). Based on an overall consideration, the BF-PMCs/H2O2 system has great potential for degradation of emerging organic pollutants (EOPs) in natural water systems.

Preparation and properties of microfibrillated cellulose with different carboxyethyl content.

Carboxyethyl reaction was used as a pretreatment method before grinding and homogenization to prepare microfibrillated cellulose (MFC). The effect of carboxyethylation on the properties of cellulose materials and prepared MFC samples were investigated. Results showed that cellulose materials with different carboxyethyl content were obtained by controlling the chemical dosage. This reaction increased the water retention value, decreased the degree of polymerization and crystallinity, and changed the crystalline structure of cellulose. After pretreatment, the cellulose fibers were easier to be swelled and fibrillated, which greatly reduces the frequency of grinding. In addition, the diameter of the produced MFC decreased with the increase of carboxyl content. The charge density, suspension stability and transparency of MFC increased obviously due to the presence of carboxyethyl groups. This study provides a comprehensive understanding of carboxyethyl pretreatment for the preparation of MFC, which may help to enrich and promote the preparation and application of MFC.

Cellulose acetate fibers prepared from different raw materials with rapid synthesis method.

Transesterification is a mild process to prepare cellulose acetate (CA) as compared with the traditional method. In this study, CA fibers were produced from six cellulose raw materials based on a simple and rapid transesterification method. The properties of the CA solutions and the obtained CA fibers were investigated in detail. Results showed that all of the cellulose raw materials were esterified within 15 min, and spinning dopes could be obtained by concentrating the CA solutions via vacuum distillation. The XRD, FT-IR, (1)H, (13)C and HSQC NMR analysis confirmed the successful synthesis of CA. The degree of substitution (DS) of the obtained CA was significantly affected by the degree of polymerization (DP) of cellulose raw materials, which further influenced the viscosity of CA solutions as well as the structural, thermal and mechanical properties of the CA fibers.

Highly thermostable, flexible, and conductive films prepared from cellulose, graphite, and polypyrrole nanoparticles.

In this study, graphite powder (GP) was introduced into the conductive cellulose/polypyrrole (PPy) composite films to increase their conductivity and thermal stability. The GP was dispersed in ionic liquid 1-butyl-3-methylimidazolium chloride ([Bmim]Cl) before the dissolution of cellulose, and the cellulose/GP/PPy films were prepared by in situ chemical polymerization of PPy nanoparticles on the film surface. The structural characteristics and properties of the composite films were investigated in detail. The GP flakes, which were embedded in the cellulose matrix, increased the thickness and decreased the density of the films, leading to the decrement of mechanical properties. However, the thermal stability of the films was significantly improved by the incorporation of graphite, and the composite film could even substantially maintain the original shape after being burned. In addition, the electrical conductivity of the films was increased seven times, leading to the excellent electromagnetic interference shielding effectiveness. The cellulose/GP/PPy film could be considered as a potential candidate for the effective lightweight electromagnetic interference shielding materials in electronics, radar evasion, aerospace, and other applications.

Hydrothermal microwave valorization of eucalyptus using acidic ionic liquid as catalyst toward a green biorefinery scenario.

The application of the acidic ionic liquid (IL), 1-butyl-3-methylimidazolium hydrogensulfate ([bmim]HSO4), as a catalyst in the hydrothermal microwave treatment (HMT) and green upgradation of eucalyptus biomass has been investigated. The process was carried out in a microwave reactor system at different temperatures (140-200°C) and evaluated for severities. The xylooligosaccharides (XOS, refers to a DP of 2-6) yield up to 5.04% (w/w) of the initial biomass and 26.72% (w/w) of xylan were achieved. Higher temperature resulted in lower molecular weight product, and enhanced the concentration of monosaccharides and byproducts. The morphology and structure of the solid residues were performed using an array of techniques, such as SEM, XRD, FTIR, BET surface area, and CP/MAS (13)C NMR, by which the increase of crystallinity, the destruction of surface structure, and the changes in functional groups and compositions were studied after the pretreatment, thus significantly enhancing the enzymatic hydrolysis.

Bimetallic cerium-copper nanoparticles embedded in ordered mesoporous carbons as effective catalysts for the selective catalytic reduction of NO with NH3.

Bimetallic cerium-copper nanoparticles embedded in ordered mesoporous carbons (OMCs) with various Ce/Cu ratios were synthesized by "one-pot" self-assembly method, and their activities for the selective catalytic reduction (SCR) of NO with ammonia were studied. The structural and textural properties, surface chemistry, acidity, and reducibility were investigated by various techniques. Results showed that NO conversion was greatly influenced by the weight ratio of Ce to Cu. An appropriate Ce/Cu ratio in OMCs could enhance catalytic performance; the optimal catalytic performance was obtained with Ce5Cu5-OMC. Ordered mesoporous structures were formed for all synthesized samples. When Ce or Cu was incorporated into the OMCs, the amount of surface acidic oxygen functional groups increased, thereby promoting the acidic properties of the OMCs, especially those of the Cu-rich OMCs. The surface Cu(2+) species may accelerate ammonia activation and may play an important role in SCR reaction. The temperature-programmed reduction results illustrated that the Cu-rich OMCs had better reducibility, and the appropriate Ce/Cu ratio could further enhance the redox ability of the CexCuy-OMC catalysts. The existing redox cycle (Ce(4+)+Cu(+)↔Cu(2+)+Ce(3+)) promoted the activation of NH3 and consequently improved NH3-SCR activity.

Combined effects of raw materials and solvent systems on the preparation and properties of regenerated cellulose fibers.

To investigate the combined effects of materials and solvents on the preparation, structural and mechanical properties of regenerated cellulose fibers, four cellulosic materials (microcrystalline cellulose, cotton linter pulp, bamboo pulp and bleached softwood sulfite dissolving pulp) and six non-derivative solvents (NaOH/urea aqueous solution, N,N-dimethylacetamide/lithium chloride, N-methyl-morpholine-N-oxide, 1-butyl-3-methylimidazolium chloride, 1-allyl-3-methylimidazolium chloride and 1-ethyl-3-methylimidazolium acetate) were used to prepare fibers with wet spinning method. The results showed that the dissolvability of solvent was the determining factor in cellulose dissolution, and the dissolving time was influenced by the raw materials' properties, such as molecular weight, exposed area and hemicellulose content. The crystallinity and elongation at break of the fibers were almost fixed and not affected by the materials and solvents. However, the tensile strength of the fibers was directly proportional to the molecular weight of the raw materials, and varied with the type of solvents through cellulose degradation.

Effects of polymorphs on dissolution of cellulose in NaOH/urea aqueous solution.

This study focused on the effect of cellulose crystal type on the dissolution of cellulose in aqueous NaOH/urea. Cellulose I, II, IIII, and IVI were prepared and characterized. Subsequently, the solubility of these cellulose samples in aqueous NaOH/urea was tested and the mechanism was determined by a combination of (1)H NMR spectroscopy and differential scanning calorimetry (DSC). The results indicated that, compared with the degree of polymerization (DP) and crystallinity index of cellulose, the cellulose crystal type had greater impact on cellulose dissolution. Specially, the solubility of the cellulose I, II, and III was progressively decreased, probably due to different hydrogen bond network and packing energy in it. The ability of cellulose I, II, III, and IV to form hydrogen bonds with sodium hydroxides was nearly the same, while gradually increased when cellulose preparations were associated with urea. Moreover, all the cellulose solutions showed good thermal stability.

Alkali metal poisoning of a CeO2-WO3 catalyst used in the selective catalytic reduction of NOx with NH3: an experimental and theoretical study.

The alkali metal-induced deactivation of a novel CeO(2)-WO(3) (CeW) catalyst used for selective catalytic reduction (SCR) was investigated. The CeW catalyst could resist greater amounts of alkali metals than V(2)O(5)-WO(3)/TiO(2). At the same molar concentration, the K-poisoned catalyst exhibited a greater loss in activity compared with the Na-poisoned catalyst below 200 °C. A combination of experimental and theoretical methods, including NH(3)-TPD, DRIFTS, H(2)-TPR, and density functional theory (DFT) calculations, were used to elucidate the mechanism of the alkali metal deactivation of the CeW catalyst in SCR reaction. Experiments results indicated that decreases in the reduction activity and the quantity of Brønsted acid sites rather than the acid strength were responsible for the catalyst deactivation. The DFT calculations revealed that Na and K could easily adsorb on the CeW (110) surface and that the surface oxygen could migrate to cover the active tungsten, and then inhibit the SCR of NO(x) with ammonia. Hot water washing is a convenient and effective method to regenerate alkali metal-poisoned CeW catalysts, and the catalytic activity could be recovered 90% of the fresh catalyst.

Roles of Li+ and Zr4+ cations in the catalytic performances of Co(1-x)M(x)Cr(2)O(4) (M = Li, Zr; x = 0-0.2) for methane combustion.

Co(1-x)M(x)Cr(2)O(4) (M = Li, Zr; x = 0-0.2) catalysts were prepared via the citric acid method and investigated for catalytic combustion of methane. Substitution at tetrahedral (A) sites with monovalent (Li) or tetravalent (Zr) metal ions led to a decrease or increase of the catalytic activity, respectively. The Co(0.95)Zr(0.05)Cr(2)O(4) catalyst proved to be the most active and its catalytic activity reached 90% of methane conversion at 448 °C, which dropped by 66 °C compared with that of the undoped CoCr(2)O(4) catalyst. XRD and Raman results indicated that lithium or zirconium substitution could modify the spinel structure and electronic properties. For lithium-doped catalysts, oxygen deficiency and a strong surface enrichment in lithium and chromium were detected. Zirconium substitution enhanced the reducibility of zirconium-doped catalysts and decreased the strength constant of both the Co-O band and the Cr-O band, which may contribute to the catalytic activity toward methane combustion. In addition, the prevalent catalytic combustion activity of the zirconium-substituted catalysts could be explained by their higher concentration of suprafacial, weakly chemisorbed oxygen.

Speciation analysis of arsenic and selenium compounds by CE-dynamic reaction cell-ICP-MS.

A dynamic reaction cell ICP-MS was used as a CE detector for the speciation analysis of arsenic and selenium. Samples containing arsenite, arsenate, monomethylarsonic acid, dimethylarsinic acid, arsenobetaine, selenite, selenate, selenocysteine, selenomethione, and Se-methylselenocysteine were subjected to electrophoretic separation before being introduced into the microconcentric nebulizer (CEI-100) for their determination by ICP-MS. The separation has been achieved in a 60 cm length x 75 microm id fused-silica capillary. The electrophoretic buffer used was 25 mmol/L CAPS, and 0.5 mmol/L SDS at pH 9.5, whereas the applied voltage was set at 25 kV. The potentially interfering (38)Ar(40)Ar(+) and (40)Ar(40)Ar(+) at the selenium masses m/z 78 and 80 were reduced in intensity by approximately three orders of magnitude by using 1.4 mL/min CH(4) as reactive cell gas in the dynamic reaction cell. Arsenic was determined as the adduct ion (75)As(12)CH(2) (+) at m/z 89. The LOD for arsenic and selenium was in the range of 0.6-1.8 ng/mL, and 0.5-1.4 ng/mL, respectively, based on peak height. This method has been applied to determine various arsenic and selenium compounds in NIST SRM 1633a Coal Fly Ash and NRCC DOLT-3 Dogfish Liver reference materials and a selenium dietary supplement. The arsenic and selenium compounds were extracted from fish liver and dietary supplement by using Protease XIV and Lipase, and from coal fly ash with HF solution. The spike recoveries were in the range 91-103% for all the species studied.

Determination of cobalamin in nutritive supplements and chlorella foods by capillary electrophoresis-inductively coupled plasma mass spectrometry.

A capillary electrophoresis-inductively coupled plasma mass spectrometric (CE-ICP-MS) method for the determination of cobalamin is described. Samples of cobalt-containing compounds were subjected to electrophoretic separation before injection into the microconcentric nebulizer (CEI-100) of ICP-MS. The Co-containing compounds studied include cyanocobalamin (CN-Cbl, vitamin B12), hydroxocobalamin (OH-Cbl), and Co(II). The species studied were well separated using a 70 cm lengthx75 microm i.d. fused silica capillary with the applied voltage set at +20 kV. A 25 mM Tris buffer (pH 9.0) containing 15 mM sodium dodecyl sulfate (SDS) was used as the electrophoretic buffer. The CE-ICP-MS detection limits were 0.3, 0.2, and 1.7 ng of Co mL(-1) for CN-Cbl, OH-Cbl, and Co(II), respectively. The concentrations of cobalamin compounds were determined in selected nutritive supplements and chlorella samples. A microwave-assisted extraction method was used for the extraction of these compounds. Over 92% of the total cobalt species was extracted using a 5% v/v HNO3 solution in a focused microwave field within a period of 10 min; spike recovery was in the range of 94-105% for various species. The major cobalt species in nutritive supplements and chlorella samples was cyanocobalamin.

Determination of iodine and bromine compounds in foodstuffs by CE-inductively coupled plasma MS.

A CE-inductively coupled plasma mass spectrometric (CE-ICP-MS) method for iodine and bromine speciation analysis is described. Samples containing ionic iodine (I(-) and IO(3)(-)) and bromine (Br(-) and BrO(3)(-)) species are subjected to electrophoretic separation before injection into the microconcentric nebulizer (CEI-100). The separation has been achieved in a 50 cm length x 75 microm id fused-silica capillary. The electrophoretic buffer used is 10 mmol/L Tris (pH 8.0), while the applied voltage is set at -8 kV. Detection limits are 1 and 20-50 ng/mL for various I and Br compounds, respectively, based on peak height. The RSD of the peak areas for seven injections of 0.1 microg/mL I(-), IO(3)(-) and 1 microg/mL Br(-), BrO(3)(-) mixture is in the range of 3-5%. This method has been applied to determine various iodine and bromine species in NIST SRM 1573a Tomato Leaves reference material and a salt and seaweed samples obtained locally. A microwave-assisted extraction method is used for the extraction of these compounds. Over 87% of the total iodine and 83% of the total bromine are extracted using a 10% m/v tetramethylammonium hydroxide (TMAH) solution in a focused microwave field within a period of 10 min. The spike recoveries are in the range of 94-105% for all the determinations. The major species of iodine and bromine in tomato leaves, salt, and seaweed are Br(-), IO(3)(-), I(-), and Br(-), respectively.