Cellulose-based yellow-green emitting carbon dots with large Stokes shift as effective "turn off-on" fluorescence platforms for Cr (VI) and AA dual efficacy detection.

Background: Hexavalent chromium (Cr (VI)) is highly carcinogenic to humans. Ascorbic acid (AA) deficiency can be hazardous to health. And the dual-effect fluorescence detection of them is an important research topic.

[Experimental teaching reform of polymer molar mass determination using gel permeation chromatography coupled with light scattering].

Gel permeation chromatography coupled with light scattering (GPC-LS) is among the most common methods for determining the molar masses of polymers. GPC-LS is widely used in polymer science research and has been adopted for many industrial applications owing to its high sensitivity, accuracy, and precision. The determination of polymer molar masses using GPC-LS is an important experimental component of the "Polymer Physics Experiments" course.

The preparation and dual-mode detection of ascorbic acid based on poly(-isopropylacrylamide) nanogel with oxidase-like activity.

Nanozymes have recently become a research hotspot because of the advantages of good stability, excellent catalytic performance and easy storage in comparison to natural enzymes. Nanozymes with oxidase-like activity get special attention because they needn't the participation of hydrogen peroxide. In this paper, poly(-isopropylacrylamide) nanogel with oxidase-like activity was synthesized for the first time.

Water state, thermal transition behavior and structure of hydrated gelatin films.

The state of water, thermal transition behaviors, molecular interactions, crystalline structure, and mechanical performance of hydrated gelatin films were studied by differential scanning calorimetry (DSC), infrared spectroscopy (FTIR), X-ray diffraction, and universal testing instruments. The DSC results showed that with increase of the water content, two types of water, including unfreezable bound water and freezable water, appeared in turn. Below a critical water content of 30%, the glass transition temperature () of the hydrated gelatin films decreased notably with an increase in water content, which leveled off at water content higher than this threshold.

Structure and properties of citric acid cross-linked chitosan/poly(vinyl alcohol) composite films for food packaging applications.

In this study, the composite films of poly(vinyl alcohol) and citric acid cross-linked chitosan were prepared, and the effect of mass ratio on their structure and properties was investigated in detail. Chitosan was cross-linked by citric acid via an amidation reaction at an elevated temperature, which was confirmed by infrared spectra and X-ray photoelectron spectra. Chitosan is miscible with PVA due to the formation of strong hydrogen bonds between them.

High capacity and fast removal of Cr(vi) by alkali lignin-based poly(tetraethylene pentamine-pyrogallol) sorbent.

In this work, a novel alkali lignin-based adsorption material, alkali lignin-based poly(tetraethylene pentamine-pyrogallol) (AL-PTAP), was prepared using a Mannich reaction and catechol-amine reaction for removal of Cr(vi). It was characterized by thermogravimetric analysis (TGA), scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FT-IR) and X-ray photoelectron spectroscopy (XPS). The effects of tetraethylene pentamine (TEPA) dosage, pyrogallol (PL) dosage, contact time, pH, temperature and other factors on the adsorption behavior of the adsorbent were systematically investigated.

Ultrathin Membranes for Separations: A New Era Driven by Advanced Nanotechnology.

Ultrathin membranes are at the forefront of membrane research, offering great opportunities in revolutionizing separations with ultrafast transport. Driven by advanced nanomaterials and manufacturing technology, tremendous progresses are made over the last 15 years in the fabrications and applications of sub-50 nm membranes. Here, an overview of state-of-the-art ultrathin membranes is first introduced, followed by a summary of the fabrication techniques with an emphasis on how to realize such extremely low thickness.

Insight into the synergistic adsorption-reduction character of chromium(VI) onto poly(pyrogallol-tetraethylene pentamine) microsphere in synthetic wastewater.

Facile fabrication of the ultra-high-performance adsorbent can effectively ameliorate the Cr(VI)-pollution elimination in sewage control. Herein, a simple synthesis strategy is proposed to tap a versatile chelating resin poly(pyrogallol-tetraethylene pentamine) (PPTA) with respect to Cr(VI) removal from solution. Multiple changing factors which affect the adsorption behavior of PPTA are explored sequentially, such as initial pH, adsorbate concentration, adsorbent dosage, temperature, foreign ions, etc.

Facile Synthesis of Polyethylene Glycol@Tannin-Amine Microsphere towards Cr(VI) Removal.

Herein, a synthetic strategy for a rough microsphere Cr(VI)-adsorbent via the reaction of tannic acid (TA) and 1,6-hexanediamine (HA) and using polyethylene glycol (PEG) as surface modifier was presented. This adsorbent was characterized by a Fourier Transform Infrared spectrometer (FTIR), thermogravimetic analysis (TGA), X-ray photoelectron spectroscopy (XPS), etc. Certain factors, including contact time, PEG@poly(tannin-1,6-hexanediamine) (PEG@PTHA) dosage, initial concentration, and experimental temperature affecting the Cr(VI) adsorption performance of adsorbent were explored.

Probing mesoporous character, desulfurization capability and kinetic mechanism of synergistic stabilizing sorbent CaCuMnO/MAS-9 in hot coal gas.

Developing structurally stable sorbents for high-temperature HS direct removal is recognized as a valuable energy-saving strategy for efficient utilization of hot coal gas (HCG), which depends upon their mesoporous features and desulfurization capabilities. Herein, tailored hierarchical CaCuMnO/MAS-9 sorbents were fabricated via a facile sol-gel method using high-activity phase CaCuMnO anchored onto versatile mesoporous MAS-9. After O/S-exchange procedure, noteworthy straight channels of MAS-9 (S = 808 m g) provided enough available spaces for the storage of generative large MeS nanoparticles, which was better than other conventional zeolites.

Lattice substitution and desulfurization kinetic analysis of Zn-based spinel sorbents loading onto porous silicoaluminophosphate zeolites.

Green Zn-based spinel sorbents for hot coal gas desulfurization have been developed with the assistance of optimization procedures. The pilot study highlights an outstanding ordered mesoporous support (S = 323 m g, Da = 4.3 nm) of SAPO-34@as-prepared SBA-15 (SS) for loading active metal oxides.

Facile Preparation of Tannic Acid-Poly(vinyl alcohol)/Sodium Alginate Hydrogel Beads for Methylene Blue Removal from Simulated Solution.

A novel hydrogel bead [tannic acid (TA)-poly(vinyl alcohol) (PVA)/sodium alginate (SA)] with high strength prepared by biocompatible PVA, TA, and biocompatible SA via an instantaneous gelation method was applied to remove methylene blue (MB) from aqueous solution. The obtained TA-PVA/SA hydrogel beads were fully characterized by thermogravimetric analysis, Fourier-transform infrared spectroscopy, X-ray photoelectron spectroscopy, scanning electron microscopy, and so on. The adsorption performances of TA-PVA/SA hydrogel beads for MB were investigated by changing the factors of TA content, initial concentration, pH, adsorbent dosage, contact time, and temperature systematically.

Highly Sensitive Detection of Melamine Based on the Fluorescence Resonance Energy Transfer between Conjugated Polymer Nanoparticles and Gold Nanoparticles.

Adding melamine as additives in food products will lead to many diseases and even death. However, the present techniques of melamine detection require time-consuming steps, complicated procedures and expensive analytical apparatus. The fluorescent assay method was facile and highly sensitive.

Toxic Cr removal from aqueous media using catechol-amine copolymer coating onto as-prepared cellulose.

Green composite adsorbent with low cost and high efficiency towards toxic Cr(VI) removal from the polluted water has a broad application prospect. In this work, a mussel-inspired Cr-adsorbent namely poly(catechol tetraethylenepentamine-p-phenylenediamine)@as-prepared cellulose (PAC@AC) is successful fabricated via catechol-amine copolymer adhering onto as-prepared cellulose (AC). The detailed characterizations of product are run with SEM, FT-IR, TGA, XRD, EDS and XPS analysis.

Green synthesis of tannin-hexamethylendiamine based adsorbents for efficient removal of Cr(VI).

Newly developed adsorbents, poly(tannin-hexamethylendiamine) (PTHA), were fabricated by varying the mole ratio of tannin (TA) and hexamethylendiamine (HA) under one-pot reaction. The specific forming process of the adsorbent which had undergone the transition from hydrogen bonds to covalent bonds was subsequently explored. Based on the efficiency of Cr(VI) removal from aqueous solution over all prepared adsorbents, the PTHA-4 (mole ratio of TA/HA = 1:12.

A novel label-free photoelectrochemical sensor based on N,S-GQDs and CdS co-sensitized hierarchical ZnSnO cube for detection of cardiac troponin I.

A novel label-free photoelectrochemical (PEC) sensor based on graphene quantum dots doped with nitrogen and sulfur (N,S-GQDs) and CdS co-sensitized hierarchical ZnSnO cube was fabricated to detect cardiac troponin I (cTnI). The unique hierarchical ZnSnO cube was synthesized successfully by the solvothermal method, which has a large specific surface to load functional materials. N,S-GQDs nanoparticles were assembled to the surface of cubic ZnSnO coated ITO electrode, which efficiently accelerated the electronic transition and improved photo-to-current conversion efficiency.

Effect of salt on the coil-helix transition of gelatin at early stages: Optical rotation, rheology and DSC studies.

The influence of the concentration and type of salt on the physical gelation of gelatin at early stages was explored by polarimeter, rheometer and differential scanning calorimetry (DSC). With the increase of salt concentration, both the triple helix content and the storage modulus of gelatin increased slightly and then decreased in CaCl solutions, whereas they decreased monotonically in NaCl and CrCl solutions. The addition of CaCl at low concentrations facilitated the coil-helix transition of gelatin, which could be significantly inhibited by high salt concentrations.

Removal of Cu(II) from aqueous solution using synthetic poly(catechol-diethylenetriamine-p-phenylenediamine) particles.

A novel poly(catechol-diethylenetriamine-pphenylenediamine)(PCEA) adsorbent was synthesized in methanol, with chelating groups supplied by catechol and diethylenetriamine, which showed a strong removal performance and efficient adsorption toward Cu(II) ions in aqueous solution. The adsorbent was characterized by scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR) and thermogravimetric analysis (TGA). Besides, factors such as adsorbent dosage, pH, initial ionic and metal concentrations, contact time, and temperature on the adsorption of Cu(II) were studied.

Self-healing surface hydrophobicity by consecutive release of hydrophobic molecules from mesoporous silica.

The paper reports a novel approach to achieve self-healing surface hydrophobicity. Mesoporous silica is used as the reservoir for hydrophobic molecules, i.e.

Highly selective uptake and release of charged molecules by pH-responsive polydopamine microcapsules.

A systematic study of the permeation of small molecules through Pdop microcapsules is reported. The zwitterionic Pdop microcapsules are prepared by oxidative polymerization of dopamine on polystyrene microspheres followed by core removal with THF. Rhodamine 6G, methyl orange and alizarin red are chosen as differently charged probing dyes.