Fabrication of highly dispersed carbon doped Cu-based oxides as superior selective catalytic oxidation of ammonia catalysts via employing citric acid-modified carbon nanotubes doping CuAl-LDHs

In this work,the CuAl-LDO/c-CNTs catalyst was fabricated via in situ oriented assembly of layered-double hydroxides(LDHs)and citric acid-modified carbon nanotubes(c-CNTs)followed by annealing treatment,and evaluated in the selective catalytic oxidation(SCO)of NH_(3)to N_(2).The CuAl-LDO/c-CNTs catalyst presented better catalytic performance(98%NH_(3)conversion with nearly 90%N_(2)selectivity at 513 K)than other catalysts,such as CuAlO_(x)/CNTs,CuAlO_(x)/c-CNTs and CuAl-LDO/CNTs.Multiple characterizations were utilized to analyze the difference of physicochemical properties among four catalysts.XRD,TEM and XPS analyses manifested that CuO and Cu_(2)O nanoparticles dispersed well on the surface of the Cu Al-LDO/c-CNTs catalyst.Compared with other catalysts,larger specific surface area and better dispersion of CuAl-LDO/c-CNTs catalyst were conducive to the exposure of more active sites,thus improving the redox capacity of the active site and NH_(3)adsorption capacity.In-situ DRIFTS results revealed that the internal selective catalytic reduction(iSCR)mechanism was found over CuAl-LDO/c-CNTs catalyst.

STUDY ON THE PROPERTIES OF ACID-MODIFIED MULTIFUNCTION COPOLYESTER FIBRE

Applying conventional analytical methods,the following results have been found:the satura-tion value of acid--modified multifunction copolyest fibre( acid-modified polyester fibre)is1.74,then this kind of fibre is good for being dyed medium and light colours with cationicdyes;its level of erystalization is lower than of PET fibre;the third monomer(SIPM)con-tent in the fibre will be reduced by about 8% by the "alkali treatment"in dyeing and finishingprocess:through measuring and analysing the dye-up-take curves of time and temperature ofdyeing the fibre with cationic dyes,we indicate the key factors in dyeing are the 100℃ dyeingtemperature and the time for heat preservation;moveover,adding sodium sulphate will help leveldyeing but lower the dye-uptake.

Scavenger receptor A-mediated nanoparticles target M1 macrophages for acute liver injury

Acute liver injury(ALI)has an elevated fatality rate due to untimely and ineffective treatment.Although,schisandrin B(SchB)has been extensively used to treat diverse liver diseases,its therapeutic efficacy on ALI was limited due to its high hydrophobicity.Palmitic acid-modified serum albumin(PSA)is not only an effective carrier for hydrophobic drugs,but also has a superb targeting effect via scavenger receptor-A(SR-A)on the M1 macrophages,which are potential therapeutic targets for ALI.Compared with the common macrophage-targeted delivery systems,PSA enables site-specific drug delivery to reduce off-target toxicity.Herein,we prepared SchB-PSA nanoparticles and further assessed their therapeutic effect on ALI.In vitro,compared with human serum albumin encapsulated SchB nanoparticles(SchB-HSA NPs),the SchB-PSA NPs exhibited more potent cytotoxicity on lipopolysaccharide(LPS)stimulated Raw264.7(LAR)cells,and LAR cells took up PSA NPs 8.79 times more than HSA NPs.As expected,the PSA NPs also accumulated more in the liver.Moreover,SchB-PSA NPs dramatically reduced the activation of NF-κB signaling,and significantly relieved inflammatory response and hepatic necrosis.Notably,the high dose of SchB-PSA NPs improved the survival rate in 72 h of ALI mice to 75%.Hence,SchB-PSA NPs are promising to treat ALI.

Analysis of Chemical Modification Mechanism and Rheological Properties of Polyphosphoric Acid Modified Asphalt

In order to study the chemical modification mechanism and rheological properties of polyphosphoric acid (PPA)-modified asphalt,asphalt modified with different PPA contents were characterized by four-component test,atomic force microscopy (AFM) and Fourier transform infrared spectroscopy (FTIR).In the test,changes in asphalt chemical composition and colloidal structure were analyzed for different PPA contents,and infrared spectra were fitted with a Gaussian function.The reaction mechanism of PPA and matrix asphalt was also discussed.Based on dynamic shear rheometer (DSR) test and bending beam rheometer (BBR) test,rheological index G~*/sinδ and S/m were used to evaluate the modification effect of PPA on asphalt.The results show that,with an increase in PPA content,both large and small honeycomb structures increased in the three-dimensional topography seen in the atomic force microscope (AFM).In a certain space range,some of the micelles in the asphalt are connected each other to form interlocking skeleton structures,and locally form dense spatial network structures.The added PPA does not chemically react with the functional groups in the functional-group area of the infrared spectra (3 100-2 750 cm^(-1),1 800-1 330 cm^(-1)),and the structure is very stable.However,there is an obvious new absorption peak below 1 330 cm^(-1) in the fingerprint area,that is,the chemical reaction between PPA and the matrix asphalt generates a new compound,inorganic phosphate.Infrared spectra of PPA-modified asphalt with different contents were fitted by a Gaussian function,which makes up for the limitation that the absorption intensity information of each superimposed functional group cannot be obtained directly from the original infrared spectra.Results of this qualitative analysis were further verified by quantitative analysis.The addition of PPA can effectively improve the high and low-temperature performance of asphalt,and the lower the temperature is in the negative temperature zone,the more obvious the improvement is.When PPA content is more than 1%,the improvement of asphalt low-temperature performance is not obvious.

Selective removal of heavy metals by Zr-based MOFs in wastewater: New acid and amino functionalization strategy

Zr-based metal-organic frameworks(MOFs)have been developed in recent years to treat heavy metals,e.g.hexavalent chromium Cr^(6+)pollution,which damages the surrounding ecosystem and threaten human health.This kind of MOF is stable and convenient to prepare,but has the disadvantage of low adsorption capacity,limiting its wide application.To this end,a novel formic acid and amino modified MOFs were prepared,referred to as Form-UiO-66-NH_(2).Due to the modification of formic acid,its specific surface area,pore size,and crystal size were effectively expanded,and the adsorption capacity of Cr6+was significantly enhanced.Under optimal conditions,Form-UiO-66-NH_(2) exhibited an excellent adsorption capacity(338.98 mg/g),∼10 times higher than that reported for unmodified Zr-based MOFs and most other adsorbents.An in-depth study on the photoelectronic properties and pH confirmed that the adsorption mechanism of Form-UiO-66-NH2 to Cr^(6+)was electrostatic adsorption.After modification,the improvement of Cr^(6+)adsorption capacity by Form-UiO-66-NH_(2) was attributed to the expansion of its specific surface area and the increase in its surface charge.The present study revealed an important finding that Form-UiO-66-NH_(2) elucidated selective adsorption to Cr^(6+)in mixed wastewater containing toxic heavymetal ions and common nonmetallic water quality factors.This research provided a new acid and amino functionalization perspective for improving the adsorption capacity of Zr-based MOF adsorbents while simultaneously demonstrating their pertinence to target contaminant adsorption.

Supramolecular approaches for insulin stabilization without prolonged duration of action

Aggregation represents a significant challenge for the long-term formulation stability of insulin therapeutics.The supramolecular PEGylation of insulin with conjugates of cucurbit[7]uril and polyethylene glycol(CB[7]-PEG)has been shown to stabilize insulin formulations by reducing aggregation propensity.Yet prolonged in vivo duration of action,arising from sustained complex formation in the subcutaneous depot,limits the application scope for meal-time insulin uses and could increase hypoglycemic risk several hours after a meal.Supramolecular affinity of CB[7]in binding the B1-Phe residue on insulin is central to supramolecular PEGylation using this approach.Accordingly,here we synthesized N-terminal acid-modified insulin analogs to reduce CB[7]interaction affinity at physiological pH and reduce the duration of action by decreasing the subcutaneous depot effect of the formulation.These insulin analogs show weak to no interaction with CB[7]-PEG at physiological pH but demonstrate high formulation stability at reduced pH.Accordingly,N-terminal modified analogs have in vitro and in vivo bioactivity comparable to native insulin.Furthermore,in a rat model of diabetes,the acid-modified insulin formulated with CB[7]-PEG offers a reduced duration of action compared to native insulin formulated with CB[7]-PEG.This work extends the application of supramolecular PEGylation of insulin to achieve enhanced stability while reducing the risks arising from a subcutaneous depot effect prolonging in vivo duration of action.