直接焚烧核燃料后处理过程中产生的磷酸三丁酯(TBP)和煤油(OK)有机废液会产生磷酸,会对设备造成一定程度的腐蚀,因此在采用热解焚烧工艺处理该废液时,需掺入合适比例的中和剂和表面活性剂等添加剂,将废液配制成均匀稳定的悬浮液。中和...直接焚烧核燃料后处理过程中产生的磷酸三丁酯(TBP)和煤油(OK)有机废液会产生磷酸,会对设备造成一定程度的腐蚀,因此在采用热解焚烧工艺处理该废液时,需掺入合适比例的中和剂和表面活性剂等添加剂,将废液配制成均匀稳定的悬浮液。中和剂在热解过程中可以固定P2O5,避免磷酸生成后对设备的腐蚀。本文通过不同单因素实验研究以Ca(OH)_(2)和Mg(OH)_(2)为中和剂对配制成的TBP/OK悬浮液性能的影响,为后处理厂热解焚烧系统提供新的悬浮液配方思路。试验结果显示:当TBP含量为30%和60%时,Mg(OH)_(2)在相同TBP含量下配制成的悬浮液的最终表面黏度远大于Ca(OH)_(2),Mg(OH)_(2)和Ca(OH)_(2)在30%TBP时的最终表面黏度分别为90.36 m Pa·s和43.42 mPa·s,在60%TBP时的最终表面黏度分别为95.24 m Pa·s和75.09 m Pa·s,同时Mg(OH)_(2)的乳化速度明显优于Ca(OH)_(2),并具有更好的流动性。以Mg(OH)_(2)为中和剂的悬浮液在不同核素和DBP含量下整体稳定性更好。展开更多
In this paper we describe a route to produce crystalline Mg(OH)2 nanopowders from serpentinite ore distributed in the Halilovskiy array(Russia, Orenburg region). An efficient extraction route consisting of treatment o...In this paper we describe a route to produce crystalline Mg(OH)2 nanopowders from serpentinite ore distributed in the Halilovskiy array(Russia, Orenburg region). An efficient extraction route consisting of treatment on serpentinite in 40% HNO_3 at 80 °C followed by NH_4OH titration for Mg(OH)_2 precipitation was demonstrated. In this study, crystalline Mg(OH)2 nanopowders have been synthesized by solvothermal reaction method using(Mg(NO_3)_2á6H_2O) which were obtained from serpentinite, NH4 OH as a precipitator, and hydroxyethylated nonylphenol as surface-active substance. Microstructure and phase composition of samples were investigated employing scanning electron microscopy(SEM) and transmission electron microscopy(TEM), X-ray phase analysis(XRD), and inductively coupled plasma optical emission spectroscopy(ICP-OES). XRD reveals that Mg(OH)2 nanopowder with high purity has the brucite structure. It was found that crystalline Mg(OH)_2 nanopowders exclusively consist of lamellar-like structures and the sizes of Mg(OH)_2 are 30–265 nm length or width.展开更多
The high activity of metallic magnesium and alloys limits its potential in biomedical applications;in recent years,extensive efforts have been devoted to modulating this reactivity.In this work,we present Mg(OH)_(2) a...The high activity of metallic magnesium and alloys limits its potential in biomedical applications;in recent years,extensive efforts have been devoted to modulating this reactivity.In this work,we present Mg(OH)_(2) and TiO_(2)barrier coatings to reduce the degradation of magnesium alloy(Mg-Ca-Zn)surfaces.These coatings were deposited by the anodization method and the spin-coating technique,respectively.The anodized layer was coated with TiO_(2)generated from the hydrolysis of 3%weight of TTIP(Ti[OCH(CH_(3))_(2)]_(4),Titanium(IV)isopropoxide)in 2-Propanol deposited by the spin-coating method.Studying the degradation in Ringer’s solution by electrochemical impedance spectroscopy and OCP revealed a 98%reduction in pittings in uncoated samples after 14 days of immersion.The p H measurements revealed that the TiO_(2)coating reduced the alkalization of the physiological environment,keeping the pH at 6.0 values.In vitro studies of two types of bacteria(E.coli and S.aureus)exhibited zones of inhibition in the agar and activity bactericidal(kill time test).The mechanisms behind the improved degradation resistance and enhanced antibacterial activity are presented and discussed here.Surface modification with Mg(OH)_(2)/TiO_(2)coatings is a promising strategy to control the biodegradation of magnesium implants for bone regeneration.展开更多
Commercially available niobium (V) oxide [Nb2O5], with barium acetate [Ba(CH3COO)2] and magnesium acetate [Mg(CH3COO)2-4H2O] was used as the starting material in the sol-gel process for preparing Ba(Mg1/3Nb2/3)O3 (BMN...Commercially available niobium (V) oxide [Nb2O5], with barium acetate [Ba(CH3COO)2] and magnesium acetate [Mg(CH3COO)2-4H2O] was used as the starting material in the sol-gel process for preparing Ba(Mg1/3Nb2/3)O3 (BMN) nanopowders. At first, Nb2O5 reacted with melting sodium hydroxide and transformed into dispersible oxide. The resulting glassy substance after cooling was dispersed and washed several times in distilled water to remove the Na+ ions. The as-prepared colloidal Nb2O5-nH2O was subsequently mixed with acetic solution of barium acetate and magnesium acetate according to the required molar proportions and followed by gelation. The ultrafine BMN powders were finally obtained after heat-treating the gel at 820℃for 1 h, and the as-sintered nanoceramics revealed a high relative density of 98.2%, and a high microwave Q-factor, of 10397 at 1.45GHz.展开更多
文摘直接焚烧核燃料后处理过程中产生的磷酸三丁酯(TBP)和煤油(OK)有机废液会产生磷酸,会对设备造成一定程度的腐蚀,因此在采用热解焚烧工艺处理该废液时,需掺入合适比例的中和剂和表面活性剂等添加剂,将废液配制成均匀稳定的悬浮液。中和剂在热解过程中可以固定P2O5,避免磷酸生成后对设备的腐蚀。本文通过不同单因素实验研究以Ca(OH)_(2)和Mg(OH)_(2)为中和剂对配制成的TBP/OK悬浮液性能的影响,为后处理厂热解焚烧系统提供新的悬浮液配方思路。试验结果显示:当TBP含量为30%和60%时,Mg(OH)_(2)在相同TBP含量下配制成的悬浮液的最终表面黏度远大于Ca(OH)_(2),Mg(OH)_(2)和Ca(OH)_(2)在30%TBP时的最终表面黏度分别为90.36 m Pa·s和43.42 mPa·s,在60%TBP时的最终表面黏度分别为95.24 m Pa·s和75.09 m Pa·s,同时Mg(OH)_(2)的乳化速度明显优于Ca(OH)_(2),并具有更好的流动性。以Mg(OH)_(2)为中和剂的悬浮液在不同核素和DBP含量下整体稳定性更好。
基金the state on behalf of the Ministry of Education and Science of the Russian Federation of the Agreement (No. 14.577.21.0111 (22 September 2014))The unique identifier of the applied research (No. RFMEFI57714X0111)
文摘In this paper we describe a route to produce crystalline Mg(OH)2 nanopowders from serpentinite ore distributed in the Halilovskiy array(Russia, Orenburg region). An efficient extraction route consisting of treatment on serpentinite in 40% HNO_3 at 80 °C followed by NH_4OH titration for Mg(OH)_2 precipitation was demonstrated. In this study, crystalline Mg(OH)2 nanopowders have been synthesized by solvothermal reaction method using(Mg(NO_3)_2á6H_2O) which were obtained from serpentinite, NH4 OH as a precipitator, and hydroxyethylated nonylphenol as surface-active substance. Microstructure and phase composition of samples were investigated employing scanning electron microscopy(SEM) and transmission electron microscopy(TEM), X-ray phase analysis(XRD), and inductively coupled plasma optical emission spectroscopy(ICP-OES). XRD reveals that Mg(OH)2 nanopowder with high purity has the brucite structure. It was found that crystalline Mg(OH)_2 nanopowders exclusively consist of lamellar-like structures and the sizes of Mg(OH)_2 are 30–265 nm length or width.
基金financed by the FOMIX-Yucatán 2008-108160,CONACYT LAB-2009-01-123913,292692,294643,188345,and 204822 projectsthe financial support received from CONACYT。
文摘The high activity of metallic magnesium and alloys limits its potential in biomedical applications;in recent years,extensive efforts have been devoted to modulating this reactivity.In this work,we present Mg(OH)_(2) and TiO_(2)barrier coatings to reduce the degradation of magnesium alloy(Mg-Ca-Zn)surfaces.These coatings were deposited by the anodization method and the spin-coating technique,respectively.The anodized layer was coated with TiO_(2)generated from the hydrolysis of 3%weight of TTIP(Ti[OCH(CH_(3))_(2)]_(4),Titanium(IV)isopropoxide)in 2-Propanol deposited by the spin-coating method.Studying the degradation in Ringer’s solution by electrochemical impedance spectroscopy and OCP revealed a 98%reduction in pittings in uncoated samples after 14 days of immersion.The p H measurements revealed that the TiO_(2)coating reduced the alkalization of the physiological environment,keeping the pH at 6.0 values.In vitro studies of two types of bacteria(E.coli and S.aureus)exhibited zones of inhibition in the agar and activity bactericidal(kill time test).The mechanisms behind the improved degradation resistance and enhanced antibacterial activity are presented and discussed here.Surface modification with Mg(OH)_(2)/TiO_(2)coatings is a promising strategy to control the biodegradation of magnesium implants for bone regeneration.
文摘Commercially available niobium (V) oxide [Nb2O5], with barium acetate [Ba(CH3COO)2] and magnesium acetate [Mg(CH3COO)2-4H2O] was used as the starting material in the sol-gel process for preparing Ba(Mg1/3Nb2/3)O3 (BMN) nanopowders. At first, Nb2O5 reacted with melting sodium hydroxide and transformed into dispersible oxide. The resulting glassy substance after cooling was dispersed and washed several times in distilled water to remove the Na+ ions. The as-prepared colloidal Nb2O5-nH2O was subsequently mixed with acetic solution of barium acetate and magnesium acetate according to the required molar proportions and followed by gelation. The ultrafine BMN powders were finally obtained after heat-treating the gel at 820℃for 1 h, and the as-sintered nanoceramics revealed a high relative density of 98.2%, and a high microwave Q-factor, of 10397 at 1.45GHz.
