Synthesis of phosphonated graphene oxide by electrochemical exfoliation to enhance the performance and durability of high-temperature proton exchange membrane fuel cells

The doping of functionalized graphene oxide(GO)in the membranes becomes a promising method for improving the performance of high-temperature proton exchange membrane fuel cells(HT-PEMFC).Phosphonated graphene oxide(PGO)with a P/O ratio of 8.5%was quickly synthesised by one-step electrochemical exfoliation based on a three-dimensiaonal(3D)printed reactor and natural graphite flakes.Compared with the GO prepared by the two-step electrochemical exfoliation method,the PGO synthesized by the one-step electrochemical exfoliation can better improve the performance of the membrane-electrode-assembly(MEA)based on the polybenzimidazole(PBI)membrane in the HTPEMFC.The doping of 1.5 wt%GO synthesised by electrochemical exfoliation with the 2-step method or reactor method in PBI increased the peak power density by 17.4%or 35.4%compared to MEA based on pure PBI membrane at 150℃,respectively.In addition,the doping of PGO in PBI improves its durability under accelerated stress test(AST).

Aminated (Cyclopropylmethyl)Phosphonates: Synthesis and Anti-Pancreatic Cancer Activity

Buoyed by the extensive research on the wide-range biological activities of aminophosphonates, a novel class of aminated (cyclopropylmethyl)phosphor-nates compounds was synthesized from diethyl ((1-(3-chloropropyl)cyclopropyl)methyl)phosphonate and various amines in the presence of Hunig’s base. Upon biological activity screening these compounds demonstrated encouraging anti-pancreatic cancer properties at low micromolar concentrations.

离子液体1-乙基-3-甲基咪唑亚磷酸甲酯盐与1-乙基-3-甲基咪唑亚磷酸乙酯盐的热物性

合成了1-乙基-3-甲基咪唑亚磷酸甲酯盐([Emim][OMP])和1-乙基-3-甲基咪唑亚磷酸乙酯盐([Emim][OEP])两种烷基咪唑亚磷酸酯离子液体,并使用核磁共振波谱仪和元素分析仪对产物进行了表征,在常压下测定了其热稳定性、相行为、密度和黏度(293.15~353.15K)、电导率和表面张力(293.15~343.15K)。采用自然对数方程关联离子液体的密度,根据实验值计算得到离子液体体积性质,包括热膨胀系数、分子体积、标准熵和晶格能。采用VFT方程关联离子液体黏度和电导率。采用线性方程关联表面张力,并根据实验值计算得到离子液体的表面熵和表面焓。实验结果表明,两种离子液体的分解温度(T_(onset))分别为271.0℃和259.2℃,玻璃化温度(T_(g))分别为-84.87℃和-85.00℃,离子液体的密度、黏度和表面张力随温度的升高而减小,而电导率随温度的升高而增大。Walden规则分析表明,两种烷基咪唑亚磷酸酯离子液体均符合Walden规则,且均被归类为“good ionic liquids”。

DTPMP在萤石和方解石浮选分离中的应用及机理

萤石(CaF_(2))是一种关键战略性矿产资源,在自然界中常与同为含钙矿物的方解石(CaCO_(3))共生。泡沫浮选是分离这两种含钙矿物最主要的方法,但萤石和方解石表面的钙活性位点相似,导致其选择性分离一直是世界性难题。萤石浮选中常用水玻璃抑制方解石,实现萤石正浮选富集。然而,水玻璃选择性低且用量大,导致部分萤石被抑制无法回收,且因其分散性好会造成尾矿难以沉降、尾水难以处理等问题。本文提出了抑制萤石浮选方解石的反浮选思路,并开发了一种绿色萤石抑制剂—二乙烯三胺五甲叉膦酸(DTPMP)。单矿物、二元混合矿及实际矿浮选试验表明,在中性pH下,以油酸钠(NaOL)作捕收剂、低用量的DTPMP作抑制剂,可实现萤石的反浮选分离。药剂吸附量检测和傅里叶变换红外光谱(FTIR)表明,DTPMP在萤石表面的吸附量更多、吸附强度更大。密度泛函理论(DFT)计算结果表明,DTPMP更容易在萤石表面吸附,且DTPMP膦酸基团中的H原子与萤石表面的F原子生成的氢键作用较强。因此,DTPMP作为一种绿色高效的抑制剂,在萤石浮选领域具有较好的工业应用前景。

钇锆双金属MOFs对有机膦阻垢剂HEDP的吸附研究

采用溶剂热法首次合成了新型钇锆双金属有机框架(YZr-MOF)吸附材料,并对其结构和表面性质进行了表征,研究了YZr-MOF对有机膦阻垢剂羟基亚乙基二膦酸(HEDP)的吸附行为和性质。实验结果表明,YZr-MOF呈现出大小均匀的球形颗粒结构,比表面积为912.862 m^(2)/g;在298 K时,YZr-MOF理论最大吸附量为66.293 mg/g(以P计)。吸附过程符合准二级动力学和Langmuir模型,吸附过程为吸热过程,温度升高有利于YZr-MOF吸附HEDP。在吸附实验中,YZr-MOF的最佳质量浓度为0.2 g/L;YZr-MOF在较宽的pH范围内有着良好的稳定性,并且经过6次循环后,仍保持显著的吸附率。结合相关实验和FTIR、XPS的表征结果表明,静电作用和配体交换为主要吸附机理。

膦酸功能化纤维素的制备及其对Au(Ⅲ)的吸附富集性能

为处理黄金冶炼工业产生的含金废水并实现其资源化利用,本研究通过多氨基多醚基甲叉膦酸与纤维素反应,设计合成了膦酸功能化纤维素(P-PC)吸附分离材料,利用红外光谱(FT-IR)、扫描电镜(SEM)对产物进行了表征分析。研究了P-PC对水溶液中Au(Ⅲ)的吸附富集性能。吸附实验表明,P-PC对Au(Ⅲ)的吸附行为符合伪一阶和伪二阶动力学模型及Langmuir等温吸附模型。当pH值为1.0时,P-PC对Au(Ⅲ)的吸附性能最佳。经过3次吸附与解吸循环后,P-PC对Au(Ⅲ)的吸附量仍超过0.5 mmol·g^(-1)。P-PC在吸附富集Au(Ⅲ)方面具有潜在的应用前景。

掺杂对铒、钕蒽基配合物的光二聚反应及光磁性能调控的影响

选择具有光化学活性的蒽甲基膦酸二乙酯(depma)为配体、部分镧系离子为金属中心构筑了3例同构的单核配合物Ln(SCN)_(2)(NO_(3))(depma)_(2)(4‐hpy)_(2)(Ln=Er(1Er),Nd(2Nd),Y(3Y)),对其单分子磁体行为、发光性质和光二聚行为等进行了研究。荧光测试显示1Er和2Nd因配体到稀土离子的能量转移而显示近红外发光,但在可见光区无明显发光行为,同时不能发生光二聚反应。而3Y可以发射黄绿色荧光,并发生光二聚反应生成[Y(SCN)_(2)(NO_(3))(depma_(2))(4‐hpy)_(2)]_(n)(3Y-UV)。磁性测试显示1Er和2Nd在低温下均表现出场诱导的慢磁弛豫性质,其中2Nd的弛豫过程主要由拉曼过程主导。通过将Er~Ⅲ或Nd~Ⅲ掺杂到3Y晶格中,得到同构配合物Ln_(0.1)Y_(0.9)(SCN)_(2)(NO_(3))(depma)_(2)(4‐hpy)_(2)(Ln=Er(1Er@Y),Nd(2Nd@Y)),测试结果表明掺杂样品可以发生部分光二聚行为,同时伴随发光颜色的变化。此外,化合物2Nd@Y光反应前后磁性也发生了变化,拉曼过程的指数从3.8(2Nd@Y)提升到5.2(2Nd@Y-UV),对应于光照前后晶格声子结构的变化。

Synergistic effects of expandable graphite and dimethyl methyl phosphonate on the mechanical properties, fire behavior, and thermal stability of a polyisocyanurate-polyurethane foam

In this study, a series of flame-retardant polyisocyanurate-polyurethane (PIR-PUR) foams were prepared using various concentrations (0-25% by weight) of expandable graphite (EG) and dimethyl methyl phosphonate (DMMP) (0-7% by weight). The effect of these additives on the properties of the PIR-PUR foams, including physico-mechanical, morphological, flame retardancy, and thermal stability, was studied. Increasing amounts of EG in the PIR-PUR foam caused a significant drop in the compression strength. However, DMMP caused the mechanical properties of PIR-PUR foam to improve compared to foam filled with EG alone. The flame retardancy of PIR-PUR foams containing both EG and DMMP was enhanced significantly compared to EG filled foams. Thermogravimetric analysis (TGA) indicated that EG enhances the thermal stability of PIR-PUR foams but that DMMP decreased it. The morphology of the residual char provided conclusive evidence for the weak thermal stability of foams filled with DMMP.

Highly efficient production of 2,5-dihydroxymethylfuran from biomass-derived 5-hydroxymethylfurfural over an amorphous and mesoporous zirconium phosphonate catalyst

The development of high-efficiency and low-cost catalysts is very crucial for the MeerweinPonndorf-Verley (MPV) reduction of biomass-derived 5-hydroxymethylfurfural (HMF) into 2,5-dihydroxymethylfuran (DHMF). In this work, an amorphous and mesoporous zirconium phosphonate catalyst (Zr-DTMP), which is a zirconium-containing organic-inorganic nanohybrid, was successfully designed and synthesized by the simple assembly of zirconium tetrachloride (ZrCl4) and diethylene triaminepenta(methylene phosphonic acid)(DTMP). Satisfactorily, when Zr-DTMP was employed for the MPV reduction of HMF in the presence of 2-butanol (secBuOH), DHMF yield could be achieved as 96.5% in 3 h under a relatively mild reaction temperature of 140℃. Systematic investigations indicated that this high catalytic activity should be mainly due to the cooperative role of enhancive Lewis acid site (Zr4+) and Lewis base site (O2-) in activating the carbonyl group of HMF and dissociating the hydroxyl group of secBuOH, respectively. Additionally, Zr-DTMP showed excellent catalytic stability, when it was successively used 5 recycles, its surface characteristics and textural properties still remained almost unchanged, and so, the catalytic activity was not obviously affected. More interestingly, Zr-DTMP could also be applied for the selective reduction of other biomass-derived carbonyl compounds, such as 5-methylfurfural (MF), furfural (FF), levulinic acid (LA), ethyl levulinate (EL) and cyclohexanone (CHN), into the corresponding products with high yields, which is beneficial to the effective synthesis of various valuable bio-based chemicals.

SYNTHESIS, CHARACTERIZATION AND RING-OPENING POLYMERIZATION OF CYCLIC (ARYLENE PHOSPHONATE) OLIGOMERS

A series of cyclic (arylene phosphonate) oligomers were prepared by reaction of phenylphosphonic dichloride (PPD) with various bisphenols under pseudo-high dilution conditions via interfacial polycondensation. The yield of cyclic (arylene phosphonate) oligomers is over 85% by using hexadecyltrimethylammoniun bromide as phase transfer catalyst (PTC) at 0 'C . The structures of the cyclic oligomers were confirmed by a combination of matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS) and IR analysis. These cyclic oligomers undergo facile ring-opening polymerization in the melt by using potassium 4,4'-biphenoxide as the initiator to give linear polyphosphonate. Free-radical ring-opening polymerization of cyclic(arylene phosphonate) oligomers containing sulfur linkages was also performed in the melt using 2,2'-dithiobis(benzothiazole) (DTB) as the initiator at 270 °C and the resulting polymer had a Mw, of 8 × 103 with a molecular weight distribution of 4. Ring-opening copolymerization of these cyclic oligomers with cyclic carbonate oligomers was also achieved. The average molecular weight of the resulting copolymer is higher than the corresponding homopolymer and the thermal stability of the copolymer is better than the corresponding homopolymer.

Synthesis,Structure and Characterization of a 3D Chiral Carboxylate and Phosphonate Metalorganic Framework Based on 1,1?-Biphenol Ligand

A novel phosphonate-based chiral metal-organic framework 1 was synthesized from C2-symmetric 1,1？-biphenol-based ligand and structurally characterized by single-crystal and powder X-ray diffraction, Fourier-transform infrared spectra（FTIR）, circular dichroism（CD） and thermogravimetric analyses（TGA）. Two neighboring Mn ions are linked by two carboxylate groups and one phosphate group to form a di-manganese unit [Mn2] and each [Mn2] cluster in 1 is linked by five ligands, generating a 3D network with fns topology. In addition, the photoluminescence properties of 1 and H4 L were investigated.

Luminescence study of europium(III) tris(β-diketonato)/phosphonate complexes in chloroform

The extraction of Eu（Ⅲ） with β-diketone, HA, and monodentate or bidentate Lewis bases, B, into chloroform and the luminescence properties of the extracted species were studied. Pivaloyltrifluoroacetone, Hpta, and 2-thenoyltfifluoroacetone, Htta, were used as the β-diketones. The Lewis bases, B, were tetraethyl methylene diphosphonate, POPO, which was bidentate, and diethyl benzylphosphonate, PhPO which was monodentate. Based on the extraction data, the stability constants, log β, of the first complexes between tfis（β-diketonato）Eu（Ⅲ） and the phosphonate, EuA3B, were determined to be 6.0 for the POPO complex and 3.40 for the PhPO complex. The Eu（Ⅲ） luminescence intensity in the EuA3POPO was larger than EuA3 where A was either pta or tta at similar concentrations of Eu（Ⅲ）, while that in Eu（pta）3PhPO was stronger than EuA3; however, in Eu（tta）3PhPO, it was weaker than Eu（tta）3. The POPO functions as a sensitizer, and the PhPO functions as a quencher for the tta chelate and as a sensitizer for the pta chelate. From the lifetime and quantum yield, φ, of the Eu（Ⅲ） luminescence in the complexes as well as the observation of the extractability of Eu（Ⅲ） with the Hpta and the phosphonates and of the luminescence spectra of the complexes, it was confirmed that the extraction of Eu（Ⅲ） was remarkably enhanced with a β-diketonate and a strong Lewis base, and also the ternary complex that was formed as the extracted species, showed luminescence enhancement. This phenomenon may be due the formation of a strong bond between the Eu（Ⅲ） and the strong Lewis base leading to more hydrophobicity in the extracted species and also to more effective energy transfer from the Lewis base to the Eu（Ⅲ）. It was not significant whether the donor atoms were N or O.

Phosphonated USY,a promising catalyst for the development of environmentally benign biodiesel(methyl acetate) process

The present study focuses on the evaluation of the potential applicability of Ultra Stable Y（USY） and phosphonated USY（1 wt%-4 wt%phosphorous loading） as heterogeneous catalysts for biodiesel（methyl acetate） production.The synthesized catalysts were characterized by powder X-ray diffraction（XRD）,Brunaer-Emmett-Teller（BET） surface area,total acidity by temperature-programmed desorption of ammonia（TPD-NH3） and Fourier Transform Infrared（FTIR） spectra.The performances of catalysts were evaluated for the transesterification of butyl acetate with methanol（a model reaction in biodiesel production）.In view to obtain a maximum yield of methyl acetate,the optimization of process parameters such as reactant molar ratio,catalyst loading,reaction temperature and reaction time was performed.All the phosphonated USY catalysts showed higher catalytic activity than the parent USY,which can be attributed to the increase of total acidity due to phosphonation.2 wt% P/USY（2% phosphorous loaded on USY） exhibited 92% methyl acetate yield with 100% selectivity,which was proved to be a potential catalyst for biodiesel production.The invented catalyst was found to be stable and reusable for five catalytic cycles,demonstrating that it might be a environmentally benign catalytic process.

Design, synthesis and in vitro evaluation of L-amino acid esters prodrugs of acyclic nucleoside phosphonates as anti-HBV agent

A series of novel L-amino acid esters prodrugs of acyclic nucleoside phosphonates was synthesized and their anti-HBV activity was evaluated in HepG2 2.2.15 cells. Compound 1d exhibited more potent anti-HBV activity and lower cytotoxicity than those of adefovir dipivoxil with EC50 and CC50 values of 0.207 μmol/L and 2530 μmol/L, respectively.

Synthesis and Structural Chemistry of Two Novel Transition Metal Organic Phosphonates

Two novel transition metal phosphonate compounds, [Co（H2BDPP）（phen）]n 1 （BDPP = p-O3PCH2（C6H4）CH2PO3, phen = 1,10-phenanthroline） and [Pb3（BCP）2]n 2 （BCP = OOC（C6H4）CH2PO3）, have been synthesized and structurally determined by X-ray single-crystal diffraction. Compound 1 crystallizes in the monoclinic system, space group C2/c with a = 21.169（4）, b = 12.001（2）, c = 7.6211（15）A, β = 98.03（3）°, V= 1917.2（6）A^3, C20H18N2O6P2Co, Mr = 505.22, Z = 8, De= 1.737 g/cm^3, p = 1.107 mm^-1, F（000） = 1020, the final R= 0.0450 and wR = 0.1306 for 2072 observed reflections （I 〉 2σ（I）. Compound 2 crystallizes in the monoclinic system, space group C2/c with a = 4.7167（9）, b = 18.753（2）, c = 22.781（3）A, β = 91.07（3）°, V= 2014.7（14）A^, C8H6O5PPb1.5, Mr = 523.88, Z = 8, Dc = 3.454 g/cm^3, p = 25.222 mm^-1, F（000） = 1856, the final R = 0.0441 and wR = 0.1906 for 2259 observed reflections （I 〉 2σ（I）. In compound 1, the 1D chain running along the c axis is bridged by four ligands （trans- HO3PCH2C6H4CH2PO3H） in four different directions to extend the structure into a three- dimensional network. In compound 2, the Pb（II） displays 4- and 5-coordination modes. There is a one-dimensional P-O-Pb band along the a axis formed by PO3 groups and Pb（II） cations. These bands are joined by μ2-O of -COO to yield two-dimensional inorganic P-O-Pb layers which are pillared by the OOCC6HaCH2PO3 ligands to form a three-dimensional network. Moreover, compound 2 displays a strong emission band attributed to the ligand-centered （LC） transition.

Synergistic effect of Ni^(Ⅱ)and Co/Fe^(Ⅲ)in doped mixed-valence phosphonate for enhancing electrocatalytic oxygen evolution

Metal organophosphonates have been explored in energy-related fields due to their high chemical and thermal stability as a type of uniformly precursor,but only few of pristine metal organophosphonate are directly used for oxygen evolution reaction(OER)catalysts.Here,a mixedvalence iron phosphonate(Fe_(3)-ppat)has been constructed and applied to OER catalysis considered the potential active sites in pillars Fe^(Ⅱ)(-H_(2)O)_(4)(COO)_(2)and inorganic layers Fe^(Ⅲ)(μ_(2)–OH)PO_(3).Specifically,isostructural trimetallic framework Fe_(1.7)Co_(0.3)Ni_(1.0)-ppat possesses a minimum overpotential(291 mV),small Tafel slope(91.65 mV dec^(-1)),and high stability up to 83 h.The enhanced catalytic performance could be mainly ascribed to the synergistic effect of Ni^(Ⅱ)equivalent occupancy in pillars and Co/Fe^(Ⅲ)in layers.

Synthesis,Characterization and X-ray Crystal Structure of 2-Methylpropan-2-aminium Methyl ((4-Fluorobenzamido)(4-fluorophenyl)methyl) phosphonate·H_2O

A new crystal of 2-methylpropan-2-aminium methyl （（4-fluorobenzamido）（4- fluorophenyl）methyl）phosphonate has been prepared at room temperature and characterized by ZH- NMR, 13C NMR, IR, MS, elemental analysis and X-ray single-crystal determination. The compound crystallizes in monoclinic space, group C2/c with a = 20.719（2）, b = 11.8559（13）, c = 18.176（2） A,β = 94.434（2）°, V= 4451.4（9） A3, Dc = 1.317 Mg/m3, Z= 8, F（000） = 1864 and μ= 0.174 mm-1. The crystal packing is stabilized by intermolecular N-H……O and O-H……O hydrogen bonds, as well as by weak π-π stacking interactions.

Synthesis, Characterization and X-ray Crystal Structure of O,O~ˊ-Dipropyl α-（2,4-Dichlorolphenoxyacylamido）-α-（4-methoxyphenyl） Methylphosphonates

A new crystal of O,Oˊ-dipropyl-α-（2,4-dichlorolphenoxyacylamido）-α-（4-methoxyphenyl） methylphosphonates has been prepared at room temperature and characterized by elemental analysis and IR,MS,1H NMR spectra,13C NMR spectra and X-ray single-crystal determination.The complex crystallizes in triclinic,space group P1 with a = 7.858（2）,b = 12.621（4）,c = 12.621（4）,α = 96.17（3）,β = 90.960（3）,γ = 90.960（3）°,V = 1243.9（7）3,Dc = 1.346 Mg/m3,Z = 2,μ = 0.362 mm-1and F（000） = 528.

Preparation and Ammonia Adsorption Performance of Titanium Phosphonate Adsorbent Materials with Hierarchically Porous Structure

Titanium phosphonate adsorbent materials with hierarchically porous structure were fabricated using the hydrolysis of tetrabutyl titanate in different organophosphonic acids solutions. Based on the macroporous structure of 100-2000 nm in size, a worm-hole like mesostructure was in the macropore walls, which was supported by the scanning electron microscopy（SEM）, transmission electron microscopy（TEM）, and N2 sorption analysis. Fourier transform infrared spectroscopy（FT-IR） data indicated the organic groups inside the solid materials framework. NH3 adsorption detection was performed using titanium phosphonate adsorbent materials and some significant results were obtained. The adsorption mechanism was also discussed in this study. Large adsorption amount（75.2 mg/g） was mainly attributed to the acid site via acid-base reactions and the physical adsorption site via Van der Waals forces. Resultant materials could effectively restrain the desorption of adsorbent NH3 back into air causing secondary pollution, so it could make a promising potential use in decontamination of gas pollutants in the future.