Dear Editor,This letter presents an organoid segmentation model based on multi-axis attention with convolution parallel block.MACPNet adeptly captures dynamic dependencies within bright-field microscopy images,improvi...Dear Editor,This letter presents an organoid segmentation model based on multi-axis attention with convolution parallel block.MACPNet adeptly captures dynamic dependencies within bright-field microscopy images,improving global modeling beyond conventional UNet.展开更多
Unsaturated polyester resin (UPR)/acrylate-terminated polyurethane (ATPU)/organo-modified montmorillonite (OMMT) nanocomposites were prepared by the in situ intercalative polymerization method. Samples were prep...Unsaturated polyester resin (UPR)/acrylate-terminated polyurethane (ATPU)/organo-modified montmorillonite (OMMT) nanocomposites were prepared by the in situ intercalative polymerization method. Samples were prepared by the sequential mixing, i.e. mixture of the ATPU and styrene (S) and OMMT were prepared in the first step; UPR was then added to the pre-intercalates of ATPU/S/OMMT. Results indicate that the mechanical properties and thermal properties of UPR/ATPU/OMMT nanocomposites greatly depend on the amount of ATPU and OMMT. Results show that the addition of ATPU could increase the impact strength of UPR/ATPU composites, but the tensile strength, flexural strength and heat resistance of the materials are obviously decreased. When the weight ratio between UPR, ATPU and OMMT were 82:15:3, the impact strength and heat distortion-temperature of nanocomposite were greatly improved, meanwhile there was little change for other properties of the nanocomposites. The synergistic enhancement effects of ATPU and OMMT on the composites were observed. The structures and morphology of the composites were investigated by X-ray diffraction, scanning electron microscopy and transmission electron microscopy.展开更多
Effect of organo-montmorillonite (OMMT) on the morphology and aging properties of various bitumens was studied. The morphology of the binders was characterized by atomic force microscopy (AFM). The influence of OM...Effect of organo-montmorillonite (OMMT) on the morphology and aging properties of various bitumens was studied. The morphology of the binders was characterized by atomic force microscopy (AFM). The influence of OMMT on physical properties of the binders before and after long-term aging and ultraviolet (UV) aging was investigated. It was observed that the effect of OMMT on the morphology and aging properties of bitumens depended on the base bitumen. In one case, OMMT affected the dispersed phase in bitumen. In the other case, OMMT affected the bitumen matrix. In both cases, OMMT caused stiffening of the modified phase. Compared with modification of the dispersed phase, modification of the matrix phase showed an obvious improvement on the physical properties as well as the better UV aging properties of bitumens, which was opposite to the long-term aging result.展开更多
Biosolids were applied with urea to produce a granulated organo-mineral fertiliser (OMF) for application by farm fertiliser equipment to a range of agricultural crops. The recommended rates of nitrogen, phosphate and ...Biosolids were applied with urea to produce a granulated organo-mineral fertiliser (OMF) for application by farm fertiliser equipment to a range of agricultural crops. The recommended rates of nitrogen, phosphate and potash were calculated for the test crops using “The Fertiliser Manual”, which assesses the nutrient requirement based on previous cropping, rainfall and soil index. The OMF produced similar crop yields compared to ammonium nitrate fertiliser when applied as a top-dressing to winter wheat, forage maize and grass cut for silage in the cropping years 2010 to 2014. In 2012 the grain yield of spring barley top-dressed with OMF was significantly lower than the conventional fertiliser treatment, due to dry conditions following application. For this reason it is recommended that OMF is incorporated into the seedbed for spring sown crops and The Safe Sludge Matrix guidelines followed. The experimental work presented shows that OMF can be used in sustainable crop production systems as a source of nitrogen and phosphorus for a range of agricultural crops.展开更多
Silica aerogels were prepared from a mixture of tetraethylorthosilicate and organo- alkoxysilanes. The effects of organo-alkoxysilanes on the mechanical properties of the silica aerogels were studied. The flexibility ...Silica aerogels were prepared from a mixture of tetraethylorthosilicate and organo- alkoxysilanes. The effects of organo-alkoxysilanes on the mechanical properties of the silica aerogels were studied. The flexibility of silica aerogels was significantly improved by incorporation of organo-alkoxysilanes. When MTES and TEOS were combined as precursors of silica areogels, with the increased amount of MTES, the apparent elastic modulus and apparent compressive strength monotonously rose. At the same organo- alkoxysilanes to TEOS ratio, the size of alkyl groups of the organo-alkoxysilanes had little effect on the mechanical properties. In series of MTES and TEOS, the lowest elastic modulus of silica skeleton and the highest compressive strength of silica skeleton were observed at MTES to TEOS ratio of around 50:50. At a certain organo-alkoxysilanes to TEOS ratio, the elastic modulus of silica skeleton increased and the compressive strength of silica skeleton decreased with the size increase of the alkvl grouns.展开更多
Organo-soluble alicyclic polyimides (ALPIs) were synthesized from an alicyclic dianhydride, 1,8-dimethyl-bicyclo[2.2.2]oct-7-ene-2,3,5,6-tetracarboxylic dianhydride (DMEA) and several multialkyl-substituted 4,4'-d...Organo-soluble alicyclic polyimides (ALPIs) were synthesized from an alicyclic dianhydride, 1,8-dimethyl-bicyclo[2.2.2]oct-7-ene-2,3,5,6-tetracarboxylic dianhydride (DMEA) and several multialkyl-substituted 4,4'-diaminodiphenylmethane compounds, including 3,3'-dimethyl-4,4'-diaminodiphenyt methane (DMDA), 3,31,5,5'-tetramethyl-4,4'-diaminodiphenyl methane (TMDA) and 3,3',5,5'-tetraethyl-4,4'-diaminodiphenylmethane (TEDA). For comparison, the aromatic polyimides (ARPIs) were synthesized from the aromatic dianhydride, 3,3',4,4'-benzophenonetetracarboxylic dianhydride (BTDA) and the same diamines. The ALPIs exhibited better solubility and transparency, but worse thermal stabilities and mechanical properties than those of the ARPIs. And the ALPIs could be dissolved in common organic solvents, such as N-methyl-2-pyrrolidinone (NMP), N,N-dimethylformamide (DMF), N,N-dimethylacetamide (DMAc), chloroform, tetrahydrofuran, m-cresol and so on. The ALPI films had an UV-Vis cut-off at 320 nm and a transmittance of higher than 80% in the visible region. In addition, the ALPIs showed thermal decomposition temperatures (T-d) of about 450degreesC, which was nearly 100degreesC lower than that of the ARPIs.展开更多
We studied the effects of nanoparticles of organo-silane(NOS) compounds in the size range of20–80 nm on physical and mechanical properties in medium density fiberboard,and used NOS at four consumption levels of 0,5...We studied the effects of nanoparticles of organo-silane(NOS) compounds in the size range of20–80 nm on physical and mechanical properties in medium density fiberboard,and used NOS at four consumption levels of 0,50,100,and 150 g kg-1dry wood fibers.Density of all treatments was kept constant at 0.67 g cm-3.The water-repellent property of organo-silane significantly reduced water absorption(WA) and thickness swelling but mechanical properties declined due to the reduced proportion of wood-fiber as organo-silane was added to the matrix:the compression ratio of MDF panels and the integrity among wood-fibers both declined,resulting in reduced mechanical properties.We recommend use of 50 g of NOS/kg wood-fiber to improve WA and thickness swelling while retaining acceptable mechanical properties.展开更多
The incorporation of clay nanoplatelets into biodegradable polymers is considered to be one of the best combinations for developing environmentally-benign high-performance materials. We utilized organo-montmorillonite...The incorporation of clay nanoplatelets into biodegradable polymers is considered to be one of the best combinations for developing environmentally-benign high-performance materials. We utilized organo-montmorillonite (OMMT) in ring-opening polymerization of bisphenol A diglycidyl ether and adipic acid to prepare biodegradable linear poly ( bisphenol A diglycidyl adipate ) / organomontmorillonite (PBA/OMMT) nanocomposites. The products were analyzed by XRD, TEM, 1H NMR, GPC, DSC and TGA. The results demonstrated that PBA/OMMT nanocomposites were successfully formed and sufficient for the ordinary heating process. OMMT was beneficial for the modification of PBA hydroxyl polyesters on branched rate and polydispersity.展开更多
FeOOH supported on organo-bentonite was prepared by organo-bentonite with good absorptive property,and the effects of dosage of the composite adsorbent,temperature,and Cr(Ⅵ)concentration on the removal rate of Cr(Ⅵ)...FeOOH supported on organo-bentonite was prepared by organo-bentonite with good absorptive property,and the effects of dosage of the composite adsorbent,temperature,and Cr(Ⅵ)concentration on the removal rate of Cr(Ⅵ)in the simulated wastewater were studied.The results indicated that the removal effect of Cr(Ⅵ)was good when the mass fraction of organo-bentonite was 3‰.The removal rate of Cr(Ⅵ)from the simulated wastewater could reach the maximum 98.37% under the following conditions:the dosage of the composite adsorbent was 1.0g;the temperature was 25℃;Cr(Ⅵ)concentration was 10mg/L;the oscillating time was 4h.展开更多
The adsorption of sulfate in aqueous solutions onto organo-nano-clay prepared by natural zeolite and cationic surfactant cetyltrimethylammonium bromide(CTAB)was studied.Parameters such as adsorbent dosage,contact time...The adsorption of sulfate in aqueous solutions onto organo-nano-clay prepared by natural zeolite and cationic surfactant cetyltrimethylammonium bromide(CTAB)was studied.Parameters such as adsorbent dosage,contact time and temperature were investigated using batch adsorption studies.The results show that the uptake of sulfate increases with the increase of contact time and temperature,and decreases with the increase of dosage.The Freundlich isotherm model is fit to explain the sulfate adsorption onto organo-nano-clay.The maximum adsorption capacity is found to be 38.02 mg/g at 40 °C.The kinetic data fit well the pseudo-second-order and Elovich models with a R2 more than 0.98.It is suggested that chemisorption is the rate-controlling step for adsorption of sulfate onto organo-nano-clay,meanwhile both intraparticle diffusion and boundary layer diffusion also contribute as well.Ion-exchange between sulfate anions and bromide ions and complexation between sulfate anions and CTAB cations are responsible for the mechanism of sulfate adsorption.展开更多
The kinetic characteristics of P adsorption and desorption by organo-mineral colloidal complexes (OMC)were studied using acid, calcareous and neutral purple paddy soils taken from Chongqing and Sichuan, China.The resu...The kinetic characteristics of P adsorption and desorption by organo-mineral colloidal complexes (OMC)were studied using acid, calcareous and neutral purple paddy soils taken from Chongqing and Sichuan, China.The results showed that the P adsorption capacity of the organo-mineral colloidal complexes differed with the soil types, being higher for the acid and calcareous purple soils than for the neutral purple soils. Partial removal of the organic matter increased the adsorption capacity of the colloidal complexes. A very significant positive correlation was found between the amounts of P desorbed from OMC and the P saturation degrees.The P adsorption reaction was quick at the early stage and slowed later. The raise of temperature increased P adsorption capacity and P adsorption rate of the colloidal complexes. The adsorption processes could be described by the Elovich equation.展开更多
The objective of the present study is to reveal the composition and characteristics of organo-mineral complexes in red soils (red soil,lateritic red soil and latosol) of south China in terms of chemical dissolution an...The objective of the present study is to reveal the composition and characteristics of organo-mineral complexes in red soils (red soil,lateritic red soil and latosol) of south China in terms of chemical dissolution and fractional peptization methos.In the combined humus,most of the extractable humus could dissolve in 0.1 M NaOH extractant and belonged to active humus (H1),and there was only a small amount of humus which could be further dissolved in 0.1 M Na4P2O7 extractant at pH 13 and was stably combined humus (H2).The H1/H2 ratio ranged from 3.3 to 33.8 in red soils,and the proportions of both H1 and total extractable organic carbon (H1+H2) in total soil organic carbon and the ratios of H1 to H2 and H1 to (H1+H2) were all higher in lateritic red soil and latosol than in red soil.The differences of combined humus composition in various red soils were directly related to the content of Fe and Al oxides.In organo-mineral complexes,the ratio of Na-dispersed fraction (G1) to Na-ground-dispersed fraction (G2) was generally smaller than 1 for red soils,but there was a higher G1/G2 ratio in red soil than in lateritic red soil and latosol.G1 fraction had a higher content of fulvic acid (FA),but G2 fraction had a higher content of humic acid (HA).The ratios of H1 to H2 and HA to FA were higher in G2 than in G1.The differences in the composition and activity of humus between G1 and G2 fractions were related to the content of free Fe and Al oxides.The quantities of complex Fe and Al,the Fe/C and Al/C atomic ratios were higher in G2 than in G1,and the ratio of Al/C was much higher than that of Fe/C.It may be deduced that aluminum plays a more important role than iron in the formation process of organo-mineral complexes in red soils.展开更多
Five soil sapmles collected from China and two soil samples from Pakistan with widely different origin and characterstics were used to study the zero point of charge(ZPC) of soil colloids.The results showed that the v...Five soil sapmles collected from China and two soil samples from Pakistan with widely different origin and characterstics were used to study the zero point of charge(ZPC) of soil colloids.The results showed that the value of zero point of charge of H-clay complexes was lower than that of H-clays in all the samples.Natural clay complexes had the highest ZPC as compared to -Hclay complex and H-clay in alfisol,closer to H-clays rather than H-clay complexes in oxisol and udult.The Delta Value of ZPT(zero point of titration )to ZPC was higher in H-Clay complexes than in H-Clays.展开更多
Different organo-montmorillonites (OMMTs) are preparedby modifying montmorillonites (MMTs) with CTAB, PA1010 salts/CTAB, PEG/CTAB, PVA/CTAB, PVP, PVP/CTAB and PA 6/CTAB, respectively. These OMMTs were studied by X-ray...Different organo-montmorillonites (OMMTs) are preparedby modifying montmorillonites (MMTs) with CTAB, PA1010 salts/CTAB, PEG/CTAB, PVA/CTAB, PVP, PVP/CTAB and PA 6/CTAB, respectively. These OMMTs were studied by X-ray diffraction and TG. The gallery sizes of them are all larger than that of sodium MMTs. And the decomposition temperatures of them are all much higher than that of MMT and the processing temperature of PA 66,especially OM- 6 and OM- 7, the decomposition temperatures of which are 451.6℃ and 439.1℃, almost the collapse temperature of the native MMT crystal lattice which is more than 500℃. Then PA 66/Clay nanocomposites were synthesized by mixing these OMMTs with PA 66 matrix via melt intercalation. Experimental results indicate that the tensile and flexural properties increase significantly,especially those of PCN - 08. The combination property of PCN- 08 is the best. TEM photos show that some clay platelets are present in the matrix as exfoliated layers, while most of the clay platelets are present as intercalated layers.展开更多
Three organo-montmorillonites were prepared using surfactants, and their adsorption behaviors toward sulfamethoxazole(SMX) were investigated. The surfactants used were cetyltrimethyl ammonium bromide(CTMAB), 3-(N...Three organo-montmorillonites were prepared using surfactants, and their adsorption behaviors toward sulfamethoxazole(SMX) were investigated. The surfactants used were cetyltrimethyl ammonium bromide(CTMAB), 3-(N,N-dimethylhexadecylammonio) propane sulfonate(HDAPS) and 1,3-bis(hexadecyldimethylammonio)-propane dibromide(BHDAP). The properties of the organo-montmorillonites were characterized by X-ray diffraction, scanning electron microscopy and N2adsorption–desorption isotherm measurements. Results showed that the interlayer spacing of montmorillonite was increased and the surface area as well as the morphology were changed. Batch adsorption experiments showed that the surfactant loading amount had a great effect on the adsorption of SMX. The adsorption process was p H dependent and the maximum adsorption capacity was obtained at p H 3 for HDAPS-Mt, while CTMAB-Mt and BHDAP-Mt showed a high removal efficiency at 3–11. The adsorption capacity increased with the initial SMX concentration and contact time but decreased with increasing solution ionic strength.Kinetic data were best described by the pseudo second-order model. Equilibrium data were best represented by the Langmuir model, and the Freundlich constant(n) indicated a favorable adsorption process. The maximum adsorption capacity of SMX was 235.29 mg/g for CTMAB-Mt, 155.28 mg/g for HDAPS-Mt and 242.72 mg/g for BHDAP-Mt. Thermodynamic parameters were calculated to evaluate the spontaneity and endothermic or exothermic nature. The adsorption mechanism was found to be dominated by electrostatic interaction,while hydrophobic interaction played a secondary role.展开更多
A novel hydrogel composite was prepared via inverse suspension polymerization using starch, acrylic acid and organo-mordenite micropowder with the cross- linker, N,N'-methylenebisacrylamide and the initiator, potassi...A novel hydrogel composite was prepared via inverse suspension polymerization using starch, acrylic acid and organo-mordenite micropowder with the cross- linker, N,N'-methylenebisacrylamide and the initiator, potassium persulfate. Fourier transform infrared spectro- scopy, X-ray diffraction spectroscopy, scanning electron microscopy, and energy dispersive spectroscopy confirmed that the acrylic acid was grafted onto the backbone of the corn starch, that the organo-mordenite participated in the polymerization, and that the addition of organo-mordenite improved the surface morphology of the hydrogel composite. The swelling capacity of the hydrogel compo- site was evaluated in distilled water, and solutions with different pH values, and various salt solutions. It was found that the incorporation of 10wt-% organo-mordenite enhanced the water absorbency by 144% (from 268 to 655 g-gl) and swelling was extremely sensitive to the pH values, the concentration of the salt solution and cation type. Swelling kinetics and water diffusion mechanism of the hydrogel composite in distilled water were also discussed. Moreover, the hydrogel composite showed excellent reversibility of water absorption even after five repetitive cycles and the hydrogel composite exhibited significant environmental-responsiveness by changing the swelling medium from distilled water to 0.1 mol. L-1 NaC1 solution. In addition, the loading and release of urea by the hydrogel composite were tested and the nutrient-slow- release capability of this material was found to be suitable for many potential applications.展开更多
基金supported by the Xinjiang Tianchi Talents Program(E33B9401)the Natural Science Foundation of Xinjiang Uygur Autonomous Region(2023D01E15)+1 种基金the National Natural Science Foundation of China(62302495)the National Natural Science Foundation of China(62373348)。
文摘Dear Editor,This letter presents an organoid segmentation model based on multi-axis attention with convolution parallel block.MACPNet adeptly captures dynamic dependencies within bright-field microscopy images,improving global modeling beyond conventional UNet.
基金This research was supported by the Science and Technology Key Project of Guangdong(A1070203).
文摘Unsaturated polyester resin (UPR)/acrylate-terminated polyurethane (ATPU)/organo-modified montmorillonite (OMMT) nanocomposites were prepared by the in situ intercalative polymerization method. Samples were prepared by the sequential mixing, i.e. mixture of the ATPU and styrene (S) and OMMT were prepared in the first step; UPR was then added to the pre-intercalates of ATPU/S/OMMT. Results indicate that the mechanical properties and thermal properties of UPR/ATPU/OMMT nanocomposites greatly depend on the amount of ATPU and OMMT. Results show that the addition of ATPU could increase the impact strength of UPR/ATPU composites, but the tensile strength, flexural strength and heat resistance of the materials are obviously decreased. When the weight ratio between UPR, ATPU and OMMT were 82:15:3, the impact strength and heat distortion-temperature of nanocomposite were greatly improved, meanwhile there was little change for other properties of the nanocomposites. The synergistic enhancement effects of ATPU and OMMT on the composites were observed. The structures and morphology of the composites were investigated by X-ray diffraction, scanning electron microscopy and transmission electron microscopy.
基金Funded by the National Natural Science Foundation of China (50773061)Self-determined and Innovative Research Funds of WUT
文摘Effect of organo-montmorillonite (OMMT) on the morphology and aging properties of various bitumens was studied. The morphology of the binders was characterized by atomic force microscopy (AFM). The influence of OMMT on physical properties of the binders before and after long-term aging and ultraviolet (UV) aging was investigated. It was observed that the effect of OMMT on the morphology and aging properties of bitumens depended on the base bitumen. In one case, OMMT affected the dispersed phase in bitumen. In the other case, OMMT affected the bitumen matrix. In both cases, OMMT caused stiffening of the modified phase. Compared with modification of the dispersed phase, modification of the matrix phase showed an obvious improvement on the physical properties as well as the better UV aging properties of bitumens, which was opposite to the long-term aging result.
文摘Biosolids were applied with urea to produce a granulated organo-mineral fertiliser (OMF) for application by farm fertiliser equipment to a range of agricultural crops. The recommended rates of nitrogen, phosphate and potash were calculated for the test crops using “The Fertiliser Manual”, which assesses the nutrient requirement based on previous cropping, rainfall and soil index. The OMF produced similar crop yields compared to ammonium nitrate fertiliser when applied as a top-dressing to winter wheat, forage maize and grass cut for silage in the cropping years 2010 to 2014. In 2012 the grain yield of spring barley top-dressed with OMF was significantly lower than the conventional fertiliser treatment, due to dry conditions following application. For this reason it is recommended that OMF is incorporated into the seedbed for spring sown crops and The Safe Sludge Matrix guidelines followed. The experimental work presented shows that OMF can be used in sustainable crop production systems as a source of nitrogen and phosphorus for a range of agricultural crops.
基金Funded by the National Natural Science Foundation of China(No.50802050)Science and Technology Research Project of Chinese Ministry of Railways
文摘Silica aerogels were prepared from a mixture of tetraethylorthosilicate and organo- alkoxysilanes. The effects of organo-alkoxysilanes on the mechanical properties of the silica aerogels were studied. The flexibility of silica aerogels was significantly improved by incorporation of organo-alkoxysilanes. When MTES and TEOS were combined as precursors of silica areogels, with the increased amount of MTES, the apparent elastic modulus and apparent compressive strength monotonously rose. At the same organo- alkoxysilanes to TEOS ratio, the size of alkyl groups of the organo-alkoxysilanes had little effect on the mechanical properties. In series of MTES and TEOS, the lowest elastic modulus of silica skeleton and the highest compressive strength of silica skeleton were observed at MTES to TEOS ratio of around 50:50. At a certain organo-alkoxysilanes to TEOS ratio, the elastic modulus of silica skeleton increased and the compressive strength of silica skeleton decreased with the size increase of the alkvl grouns.
基金This work was supported by the National Natural Science Foundation of China under the Grant for Distinguished YoungScholars (No. 59925310).
文摘Organo-soluble alicyclic polyimides (ALPIs) were synthesized from an alicyclic dianhydride, 1,8-dimethyl-bicyclo[2.2.2]oct-7-ene-2,3,5,6-tetracarboxylic dianhydride (DMEA) and several multialkyl-substituted 4,4'-diaminodiphenylmethane compounds, including 3,3'-dimethyl-4,4'-diaminodiphenyt methane (DMDA), 3,31,5,5'-tetramethyl-4,4'-diaminodiphenyl methane (TMDA) and 3,3',5,5'-tetraethyl-4,4'-diaminodiphenylmethane (TEDA). For comparison, the aromatic polyimides (ARPIs) were synthesized from the aromatic dianhydride, 3,3',4,4'-benzophenonetetracarboxylic dianhydride (BTDA) and the same diamines. The ALPIs exhibited better solubility and transparency, but worse thermal stabilities and mechanical properties than those of the ARPIs. And the ALPIs could be dissolved in common organic solvents, such as N-methyl-2-pyrrolidinone (NMP), N,N-dimethylformamide (DMF), N,N-dimethylacetamide (DMAc), chloroform, tetrahydrofuran, m-cresol and so on. The ALPI films had an UV-Vis cut-off at 320 nm and a transmittance of higher than 80% in the visible region. In addition, the ALPIs showed thermal decomposition temperatures (T-d) of about 450degreesC, which was nearly 100degreesC lower than that of the ARPIs.
基金conducted as a joint research projectfinanced by SRTTU(Iran)UPM(Malaysia)
文摘We studied the effects of nanoparticles of organo-silane(NOS) compounds in the size range of20–80 nm on physical and mechanical properties in medium density fiberboard,and used NOS at four consumption levels of 0,50,100,and 150 g kg-1dry wood fibers.Density of all treatments was kept constant at 0.67 g cm-3.The water-repellent property of organo-silane significantly reduced water absorption(WA) and thickness swelling but mechanical properties declined due to the reduced proportion of wood-fiber as organo-silane was added to the matrix:the compression ratio of MDF panels and the integrity among wood-fibers both declined,resulting in reduced mechanical properties.We recommend use of 50 g of NOS/kg wood-fiber to improve WA and thickness swelling while retaining acceptable mechanical properties.
文摘The incorporation of clay nanoplatelets into biodegradable polymers is considered to be one of the best combinations for developing environmentally-benign high-performance materials. We utilized organo-montmorillonite (OMMT) in ring-opening polymerization of bisphenol A diglycidyl ether and adipic acid to prepare biodegradable linear poly ( bisphenol A diglycidyl adipate ) / organomontmorillonite (PBA/OMMT) nanocomposites. The products were analyzed by XRD, TEM, 1H NMR, GPC, DSC and TGA. The results demonstrated that PBA/OMMT nanocomposites were successfully formed and sufficient for the ordinary heating process. OMMT was beneficial for the modification of PBA hydroxyl polyesters on branched rate and polydispersity.
文摘FeOOH supported on organo-bentonite was prepared by organo-bentonite with good absorptive property,and the effects of dosage of the composite adsorbent,temperature,and Cr(Ⅵ)concentration on the removal rate of Cr(Ⅵ)in the simulated wastewater were studied.The results indicated that the removal effect of Cr(Ⅵ)was good when the mass fraction of organo-bentonite was 3‰.The removal rate of Cr(Ⅵ)from the simulated wastewater could reach the maximum 98.37% under the following conditions:the dosage of the composite adsorbent was 1.0g;the temperature was 25℃;Cr(Ⅵ)concentration was 10mg/L;the oscillating time was 4h.
基金Project(51178159)supported by the National Natural Science Foundation of ChinaProject(CXZZ12_0236)supported by the Postgraduate Technological Innovation Program of Jiangsu Province Education Department,China
文摘The adsorption of sulfate in aqueous solutions onto organo-nano-clay prepared by natural zeolite and cationic surfactant cetyltrimethylammonium bromide(CTAB)was studied.Parameters such as adsorbent dosage,contact time and temperature were investigated using batch adsorption studies.The results show that the uptake of sulfate increases with the increase of contact time and temperature,and decreases with the increase of dosage.The Freundlich isotherm model is fit to explain the sulfate adsorption onto organo-nano-clay.The maximum adsorption capacity is found to be 38.02 mg/g at 40 °C.The kinetic data fit well the pseudo-second-order and Elovich models with a R2 more than 0.98.It is suggested that chemisorption is the rate-controlling step for adsorption of sulfate onto organo-nano-clay,meanwhile both intraparticle diffusion and boundary layer diffusion also contribute as well.Ion-exchange between sulfate anions and bromide ions and complexation between sulfate anions and CTAB cations are responsible for the mechanism of sulfate adsorption.
基金the Applied Science Foundation of the Science and Technology Commission of Chongqing,China.
文摘The kinetic characteristics of P adsorption and desorption by organo-mineral colloidal complexes (OMC)were studied using acid, calcareous and neutral purple paddy soils taken from Chongqing and Sichuan, China.The results showed that the P adsorption capacity of the organo-mineral colloidal complexes differed with the soil types, being higher for the acid and calcareous purple soils than for the neutral purple soils. Partial removal of the organic matter increased the adsorption capacity of the colloidal complexes. A very significant positive correlation was found between the amounts of P desorbed from OMC and the P saturation degrees.The P adsorption reaction was quick at the early stage and slowed later. The raise of temperature increased P adsorption capacity and P adsorption rate of the colloidal complexes. The adsorption processes could be described by the Elovich equation.
文摘The objective of the present study is to reveal the composition and characteristics of organo-mineral complexes in red soils (red soil,lateritic red soil and latosol) of south China in terms of chemical dissolution and fractional peptization methos.In the combined humus,most of the extractable humus could dissolve in 0.1 M NaOH extractant and belonged to active humus (H1),and there was only a small amount of humus which could be further dissolved in 0.1 M Na4P2O7 extractant at pH 13 and was stably combined humus (H2).The H1/H2 ratio ranged from 3.3 to 33.8 in red soils,and the proportions of both H1 and total extractable organic carbon (H1+H2) in total soil organic carbon and the ratios of H1 to H2 and H1 to (H1+H2) were all higher in lateritic red soil and latosol than in red soil.The differences of combined humus composition in various red soils were directly related to the content of Fe and Al oxides.In organo-mineral complexes,the ratio of Na-dispersed fraction (G1) to Na-ground-dispersed fraction (G2) was generally smaller than 1 for red soils,but there was a higher G1/G2 ratio in red soil than in lateritic red soil and latosol.G1 fraction had a higher content of fulvic acid (FA),but G2 fraction had a higher content of humic acid (HA).The ratios of H1 to H2 and HA to FA were higher in G2 than in G1.The differences in the composition and activity of humus between G1 and G2 fractions were related to the content of free Fe and Al oxides.The quantities of complex Fe and Al,the Fe/C and Al/C atomic ratios were higher in G2 than in G1,and the ratio of Al/C was much higher than that of Fe/C.It may be deduced that aluminum plays a more important role than iron in the formation process of organo-mineral complexes in red soils.
文摘Five soil sapmles collected from China and two soil samples from Pakistan with widely different origin and characterstics were used to study the zero point of charge(ZPC) of soil colloids.The results showed that the value of zero point of charge of H-clay complexes was lower than that of H-clays in all the samples.Natural clay complexes had the highest ZPC as compared to -Hclay complex and H-clay in alfisol,closer to H-clays rather than H-clay complexes in oxisol and udult.The Delta Value of ZPT(zero point of titration )to ZPC was higher in H-Clay complexes than in H-Clays.
基金Supported by Training Project For Innovitive Talents of Universities of Henan Province and Scientific Starting Funds For Returned Personnel From Abroad of Ministry of Education of China P. R.
文摘Different organo-montmorillonites (OMMTs) are preparedby modifying montmorillonites (MMTs) with CTAB, PA1010 salts/CTAB, PEG/CTAB, PVA/CTAB, PVP, PVP/CTAB and PA 6/CTAB, respectively. These OMMTs were studied by X-ray diffraction and TG. The gallery sizes of them are all larger than that of sodium MMTs. And the decomposition temperatures of them are all much higher than that of MMT and the processing temperature of PA 66,especially OM- 6 and OM- 7, the decomposition temperatures of which are 451.6℃ and 439.1℃, almost the collapse temperature of the native MMT crystal lattice which is more than 500℃. Then PA 66/Clay nanocomposites were synthesized by mixing these OMMTs with PA 66 matrix via melt intercalation. Experimental results indicate that the tensile and flexural properties increase significantly,especially those of PCN - 08. The combination property of PCN- 08 is the best. TEM photos show that some clay platelets are present in the matrix as exfoliated layers, while most of the clay platelets are present as intercalated layers.
文摘Three organo-montmorillonites were prepared using surfactants, and their adsorption behaviors toward sulfamethoxazole(SMX) were investigated. The surfactants used were cetyltrimethyl ammonium bromide(CTMAB), 3-(N,N-dimethylhexadecylammonio) propane sulfonate(HDAPS) and 1,3-bis(hexadecyldimethylammonio)-propane dibromide(BHDAP). The properties of the organo-montmorillonites were characterized by X-ray diffraction, scanning electron microscopy and N2adsorption–desorption isotherm measurements. Results showed that the interlayer spacing of montmorillonite was increased and the surface area as well as the morphology were changed. Batch adsorption experiments showed that the surfactant loading amount had a great effect on the adsorption of SMX. The adsorption process was p H dependent and the maximum adsorption capacity was obtained at p H 3 for HDAPS-Mt, while CTMAB-Mt and BHDAP-Mt showed a high removal efficiency at 3–11. The adsorption capacity increased with the initial SMX concentration and contact time but decreased with increasing solution ionic strength.Kinetic data were best described by the pseudo second-order model. Equilibrium data were best represented by the Langmuir model, and the Freundlich constant(n) indicated a favorable adsorption process. The maximum adsorption capacity of SMX was 235.29 mg/g for CTMAB-Mt, 155.28 mg/g for HDAPS-Mt and 242.72 mg/g for BHDAP-Mt. Thermodynamic parameters were calculated to evaluate the spontaneity and endothermic or exothermic nature. The adsorption mechanism was found to be dominated by electrostatic interaction,while hydrophobic interaction played a secondary role.
文摘A novel hydrogel composite was prepared via inverse suspension polymerization using starch, acrylic acid and organo-mordenite micropowder with the cross- linker, N,N'-methylenebisacrylamide and the initiator, potassium persulfate. Fourier transform infrared spectro- scopy, X-ray diffraction spectroscopy, scanning electron microscopy, and energy dispersive spectroscopy confirmed that the acrylic acid was grafted onto the backbone of the corn starch, that the organo-mordenite participated in the polymerization, and that the addition of organo-mordenite improved the surface morphology of the hydrogel composite. The swelling capacity of the hydrogel compo- site was evaluated in distilled water, and solutions with different pH values, and various salt solutions. It was found that the incorporation of 10wt-% organo-mordenite enhanced the water absorbency by 144% (from 268 to 655 g-gl) and swelling was extremely sensitive to the pH values, the concentration of the salt solution and cation type. Swelling kinetics and water diffusion mechanism of the hydrogel composite in distilled water were also discussed. Moreover, the hydrogel composite showed excellent reversibility of water absorption even after five repetitive cycles and the hydrogel composite exhibited significant environmental-responsiveness by changing the swelling medium from distilled water to 0.1 mol. L-1 NaC1 solution. In addition, the loading and release of urea by the hydrogel composite were tested and the nutrient-slow- release capability of this material was found to be suitable for many potential applications.