New methacrylic imidazolium poly(ionic liquid) gel with super swelling capacity for oil-in-water emulsions

A new polymeric ionic liquid gel was prepared with 1-[(2-methacryloyloxy)ethyl]-3-methylimidazolium bromide(MEMImBr) via radiation-induced polymerization and cross-linking at room temperature.The resultant PMEMImBr gel exhibits high strength and flexibility as well as special swelling behavior in oil-in-water(O/W)emulsions.The swelling behavior of PMEMImBr gel in emulsions is similar to that in water except that the swelling rate in emulsions is slightly smaller than that in water.The organic solvents with higher polarity in the emulsions contribute to the swelling of PMEMImBr gels,and the O/W proportion of emulsion in the swollen gel equals approximately that of original emulsion when the concentration of organic solvent is lower than 0.2 g/g.     

一元烷基磷（膦）酸对镅,钕,铕的萃取

测定了８种一元烷基磷（膦）酸（ＨＬ）在不同ｐＨ和不同萃取剂浓度下对示踪量三价镅、钕、铕的萃取分配比Ｄ。萃取剂包括２种二烷基磷酸（ＲＯ）２ＰＯＯＨ、５种烷基膦酸单烷基酯（ＲＯ）ＲＰＯＯＨ和１种二烷基次膦酸Ｒ２ＰＯＯＨ，其中Ｒ是正辛基、仲辛基或异辛基。由ｌｇＤ－ｐＨ和ｌｇＤ－ｌｇｃＨ２Ｌ２直线的斜率分析可知，这３种元素的萃取反应是相同的。计算了各萃取反应的表观平衡常数Ｋｅｘ。铕的被萃取能力最强，镅和钕的被萃取能力接近，在大多数情况下，镅稍低于钕。随着萃取剂分子中ＲＯ基团被Ｒ基团取代及正辛基被仲辛基或异辛基取代，萃取能力明显下降，分离因数βＥｕ／Ａｍ和βＮｄ／Ａｍ略呈上升趋势。     

辐射法制备聚丙烯酸-改性壳聚糖体系的两性凝胶

以O-马来酸酐化N-邻苯二甲酰化壳聚糖(MPCS)为中间产物,通过γ射线引发,在均相溶液体系制备含有改性壳聚糖.聚丙烯酸的两性凝胶.用红外光谱证实了接枝反应的发生.同时还系统地研究了接枝反应的影响因素,结果表明,接枝率依赖于单体浓度和所用的剂量.通过研究了接枝产物在不同pH值缓冲溶液中溶胀度的变化,结果发现,接枝产物在酸性条件(Ph<7)下溶胀较小,在碱性条件(pH>7)下溶胀度较大.而且还测试了接枝产物在DMF溶剂中的溶胀情况.     

In situ X-ray diffraction observation of smectite hydration under constant volume

Smectite (especially, montmorillonite) is the major clay mineral constituent of bentonite, which is designed to play a key role as a buffer material in geological repositories for the final disposal of radioactive waste in Japan. It is therefore crucial to understand the hydration behavior of smectite in terms of swelling during hydration and saturation processes.

Against such a background, the authors simultaneously observed behaviors of smectite swelling at the micro-level (i.e., both the generation of swelling pressure and the change of hydration state). In the experiments, deionized water was allowed to permeate into a dried specimen of smectite (named Kunipia-F®) with different dry densities (ρ_d: 0.97, 1.23, 1.43, 1.64 and 1.88 Mg/m³) under conditions of constant temperature and volume. The swelling pressure was measured using an in situ uniaxial consolidation apparatus during the water feeding process. Changes in local hydration states (i.e., one-molecular-layer hydration states to three-molecular-layer hydration states) were also simultaneously observed. Hydration among these different states propagated from the inlet side to the outlet side of the specimen. The authors discussed the relationships governing the hydration state, swelling pressure, the number of hydration moles, dry density, equilibrium final pressure, and then the dynamic mechanism behind pressure propagation.     

PVA/PVP/ws-chitosan水凝胶伤口敷料的辐射制备及性能表征

采用γ射线辐射法制备了聚乙烯醇(PVA)/聚乙烯基吡咯烷酮(PVP)脉溶性壳聚糖(ws-chitosan)共混水凝胶.研究了辐射剂量、ws-chitosan含量及增塑剂(聚乙二醇(PEG)或甘油)对水凝胶性能的影响.实验发现,随着辐射剂量的增大,凝胶分数增大,并在剂量大于27 kGy时达到饱和;ws-chitosan含量增大及加入增塑剂PEG或甘油后,水凝胶的凝胶分数和强度都会减小,而相应的溶胀度会显著增大.通过高级流变仪(ARES)对水凝胶弹性模量的测试显示,随吸收剂量的增加,凝胶强度会相应增大,但在27 kGy以上出现饱和.     

层状壳聚糖水凝胶的制备与性能

通过两步低温辐射和冷冻/解冻循环相结合的方法制备聚乙烯醇/聚氧乙烯(PVA/PEO)为基层,聚乙烯醇/壳聚糖(PVA/CS)为上层抗菌功能层的层状壳聚糖水凝胶。通过对吸收剂量、电子束流、聚合物溶液浓度等的研究确定最佳制备工艺,并通过溶胀性能、力学性能、抗菌性能及红外光谱和扫描电镜表征所得层状水凝胶的结构与性能。结果表明,该方法制备的层状壳聚糖水凝胶具有明显的层状结构,层间结合紧密,壳聚糖结构未改变;层状水凝胶的溶胀性能随着壳聚糖含量增大而逐渐增大,60%CS含量平衡溶胀度达到2 200%;层状水凝胶力学强度随着壳聚糖含量增加而先增大后减小,40%CS含量下层状水凝胶从PVA/PEO凝胶的0.35MPa提高到0.47 MPa;抗菌性能测试表明层状水凝胶对大肠杆菌和金黄色葡萄球菌均具有明显的抑菌效果,抑菌性能随着壳聚糖含量的提高而增大。     

U-10Mo/Al-Si固体扩散行为

采用扩散偶方法研究U-10Mo合金与Al-xSi(x＝0,1,2,5,7,9,质量分数)合金的固体扩散行为。实验在真空热压炉中完成,退火温度为555、570、580、590和595℃,时间为5～10h。实验结果表明：退火条件对扩散行为有显著影响,580℃是U-10Mo/Al-xSi扩散行为的重要分界点;当温度低于580℃热压退火处理时,扩散层厚度随Si含量的增加先急剧减小然后缓慢增大;当温度高于580℃时,扩散层的厚度随Si含量的增加而增加。Si含量较高(≥2%)的扩散偶扩散层厚度比低Si含量的小,扩散层呈3层结构,靠近Al-Si侧出现贫Si区。成分分析显示：Si含量较高的扩散偶,靠近U-Mo侧的扩散薄层中出现Si的富集,其成分为(U,Mo)(Al,Si)_x (x≤3);靠近Al-Si合金侧的扩散层成分为(U,Mo)(Al,Si)_x (x＞3)。     

Improvement of poly(vinyl alcohol)/poly(vinylpyrrolidone) blended hydrogel by radiation crosslinking

1IntroductionHydrogelisapolymericmaterial(syntheticornaturaJ)whichswellswhenplacedincontactwithwaterbutisnotsolubleandhastheabililtytoretainwaterwithinitsstructare.InIecentyears,muchattentionhasbeenfocusedontheresearchanddevelopmentofthepolymerhydIogelsforbiomaterials,suchascontactlenses,wounddressing,enzymeimmunoassay,cathetersanddIugdeliverysystems[1~3].Adressingisoftencoveredonthewotmdtoaccelerateitshealing.TheIearetwokindsofdiessings:drytypeandwettype.Ithasbeenreportedthatheallngwithawe…     

Influences of surfactants on the preparation of copper nanoparticles by electron beam irradiation

Electron beam radiation was applied to prepare nano-size copper in water system using polyvinyl alcohol, sodium dodecyl benzene sulfonate, gluten and polyethylene glycol as the surfactants, respectively. The irradiated products were characterized by XRD, TEM and LSPSDA. The XRD and TEM showed that relative pure copper products with an average size of 20 nm, 40 nm and 20 nm can be obtained by using gluten, PEG and SDBS as surfactant, respectively. An admixture of copper and cuprous oxide was obtained in PVA system. The LSPSDA showed that the size of the Cu nanoparticles decreased with increasing the glutin concentration.     

Assessment on radiochemical recycling of butyl rubber

The behavior of butyl rubber samples subjected to accelerated electron beams or γ-rays was studied in order to characterize its availability to radiation processing. Changes in some main properties such as average weight, molecular weight, gel content, Mooney viscosity, unsaturation level and degradation index were determined at various doses. Vulcanized butyl rubber starts significant radiodegradation at about 45 kGy. An advanced irradiation of IIR will decrease sharply the molecular weight of vulcanizates providing suitable plasticization matter for other kinds of synthetic rubbers.     

Effect of curing agent polarity on water absorption and free volume in epoxy resin studied by PALS

Microstructure and water absorption were systematically studied by positron annihilation lifetime spectroscopy (PALS), gravimetric measurements and Differential Scanning Calorimetry (DSC) for epoxy resins DER331 (E51) cured with three different kinds of amine curing agents DDS, DDM and MOCA. Experimental results indicated that the water absorption as a function of immersed time could be well fitted to Fick’s second law. Based on the gravimetric measurement, we found that the equilibrium water sorption M_∞ and the diffusion coefficients D of the epoxy resins have an order: E51-DDS > E51-DDM > E51-MOCA, which indicated that the curing agent plays an important role in determining the content of the water absorbed. Positron experimental results showed that the o-Ps lifetime dramatically decreased with the immersed time from 0 to 6 h, which suggested that water molecules were filled into free-volume holes and the interaction between the water-polymer decreased the mobility of molecular chains. In order to deeply discern the influence of water absorption upon the free volume, the continuous lifetime analysis, i.e. the maximum entropy lifetime method (MELT) was employed to obtain the distributions of the ortho-positronium (o-Ps) lifetime and the of the free-volume holes. From MELT analyses, we found the existences of two the long-lived components (τ₃ and τ₄), which indicated that two kinds of different o-Ps states exist. The shorter long-lived component (τ₃) is related to the segmental packing density in local ordered region. Compared to dry sample, two peaks of the o-Ps lifetime and the free-volume hole in the wet samples all drift to low values, especially, this drifts is more marked for the water sorption occurring at higher temperature 75 °C. This fact suggested that when the epoxy resin is in the glassy state, the interaction between the water and matrix restricts the motion of segmental chains and prevents from the free-volume hole swelling.     

聚乙烯醇水溶液的辐射效应及某些添加剂的影响

测定了几种浓度的聚乙烯醇（ＰＶＡ）水溶液辐照后的凝胶含量，随着吸收剂量的增大，凝胶含量增加，同一吸收测量下，随着ＰＶＡ浓度的增加，其凝胶含量先上升后趋于饱和，三聚氰酸，Ｎ，Ｎ′－亚甲基双丙烯酰胺和和六次甲基四胺等对ＰＶＡ水溶液的辐射交联有敏化作用，可使凝胶剂量降低。样品的电镜图也表明加入添加剂的ＰＶＡ水凝胶结构的差异。还测定了水凝胶的含水量与浸泡时间的关系及水凝胶的饱和含水量与吸收剂量的关系。     

超临界CO2环境下Fe-22Cr-25Ni奥氏体耐热钢的腐蚀行为研究

研究了Fe-22Cr-25Ni奥氏体耐热钢在600℃/700℃、15 MPa超临界CO₂环境中的高温腐蚀行为。采用拉曼光谱仪、辉光放电光谱仪、扫描电镜和能谱分析仪对腐蚀产物的成分、含量和元素分布进行表征。实验结果表明:Fe-22Cr-25Ni奥氏体耐热钢在600℃/700℃下的腐蚀动力学符合类抛物线规律,腐蚀增重的变化量随温度的升高而增大;通过观察表征结果和热力学计算得出腐蚀产物成分主要为Cr₂O₃,从气体侧到基体侧依次为最外侧的是Mn的氧化物、内部的Cr₂O₃和Mn-Cr氧化物、氧化层/基体界面处的SiO₂层,以及基体内的碳化物和内氧化物;C主要沉积于腐蚀产物表面,贫Cr区的宽度和深度随时间的增大而增大。同时根据O元素和C元素的质量比及热力学计算结果,提出C极有可能以离子状态发生内扩散。      

破损燃料棒二次氢化行为观察与分析

燃料棒在堆内运行时,由于初次破口会导致包壳发生二次氢化现象,二次氢化是导致燃料棒发生严重破损的重要因素。针对实际工况下的破损燃料棒,在中国原子能科学研究院燃料与材料检验设施（303热室）上开展了相关辐照后检验,并采用热室金相手段,对燃料棒二次氢化行为进行了观察分析。结果表明：二次氢化破口有明显的氢化肿胀现象;氢化物分阶段从内壁扩散到外壁,并形成“日爆”现象;二次氢化部位芯块温度明显升高,并会导致芯块气孔迁移、芯块晶粒长大、柱状晶生长等现象发生;相比未破损棒,破损棒二次氢化部位水侧氧化膜厚度有增加现象,但仍处于正常范围内。     

Preparation of macroporous poly(acrylamide) hydrogels by radiation induced polymerization technique

Macroporous poly(acrylamide) [poly(AAm)] hydrogels were prepared by using poly(ethylene glycol) (PEG) with three different molecular weight as the pore-forming agent during the radiation induced polymerization reaction. Scanning electron microscope graphs reveal that the macroporous network structure of the hydrogels can be adjusted by applying different molecular weights of PEG during the polymerization reaction. The swelling ratios of the PEG-modified hydrogels were much higher than those for the same type of hydrogel prepared via traditional method. However, the pulsatile swelling behavior of the PEG-modified hydrogels in water and in acetone was affected slightly by the change in the amount of the PEG.     

用辐射技术制备丙烯酰胺与丙烯酸钠共聚物水凝胶——超级吸水材料

本文描述了丙烯酰胺—丙烯酸钠水溶液辐射共聚—交联制备共聚物水凝胶的研究。在共聚体系中加入少量非离子型表面活性剂,可把单体浓度由通常的20％上下提高到50％,聚合转化率和共聚物的特性粘数也都有相当程度的提高。这一体系经辐射共聚—交联后,可得到溶胀比>1,000的共聚物水凝胶——超级吸水材料。这种共聚物水凝胶的溶胀比不仅受吸收剂量即交联密度的制约,而且与共聚物中羧钠基的含量有密切关系。     

P(AA-co-DMMC)水凝胶的γ辐射合成及pH响应行为

研究了ＤＭＭＣ：ＡＡ不同单体比值时辐射合成的Ｐ（ＡＡ－ｃｏ－ＤＭＭＣ）水凝胶在不同ｐＨ值溶液中的行为,发现了该凝胶对ｐＨ值有响应,凝胶的响应还与其组成单体的比例在关,表现为汉ＤＭＭＣ：ＡＡ为１：３、１：４、１：５、１：６时,其响应行为基本一致,在高和低ｐＨ值时,溶胀较小,在ｐＨ值等于７左右时溶胀较大,但当比例为１：２时,结果正好相反。     

The effect of grain boundary engineering on the oxidation behavior of INCOLOY alloy 800H in supercritical water

Grain boundary engineering (GBE) was applied to INCOLOY alloy 800H by means of thermomechanical processing. The oxidation behavior of GBE-treated alloy 800H exposed in supercritical water (SCW) with 25 ppb dissolved oxygen at 500 °C and 25 MPa was significantly improved as compared to 800H in the annealed condition. Gravimetry, optical microscopy, scanning electron microscopy/energy dispersive X-ray spectroscopy (SEM/EDS), X-ray diffraction (XRD), and electron backscatter diffraction (EBSD) were employed in this study to analyze the oxidation behavior of control (annealed) and GBE-treated samples. GBE improves the protective oxidation behavior by enhancing spallation resistance and reducing oxidation rate. Spallation resistance correlates with a reduction in texture of the oxide layers.     

~(60)Co-γ射线辐照合成P(AA-co-AM)/FA高吸水性复合材料

利用~(60)Co-γ射线引发合成聚丙烯酸/丙烯酰胺/黄腐酸(P(AA-co-AM)/FA)高吸水性复合材料。探讨了在室温下,吸收剂量、黄腐酸的添加量对高吸水性复合材料吸水倍率的影响,研究在60℃环境下的保水率,同时利用红外分析(FTIR)、扫描电镜(SEM)对复合材料进行结构分析。结果表明:高吸水复合材料在去离子水和w=0.9%NaCl溶液中最好吸水倍率分别为437倍、61倍,当黄腐酸添加质量分数为15%时,在60℃环境下放置12h,其保水率为54%。该方法提高了材料的吸水保水性能,克服了传统合成方法污染大、能耗高等问题,合成的高吸水性材料适合制作农林保水剂。     

Electroless nickel-plating for the PWSCC mitigation of nickel-base alloys in nuclear power plants

The feasibility study has been performed as an effort to apply the electroless nickel-plating method for a proposed countermeasure to mitigate primary water stress corrosion cracking (PWSCC) of nickel-base alloys in nuclear power plants. In order to understand the corrosion behavior of nickel-plating at high temperature water, the electrochemical properties of electroless nickel-plated alloy 600 specimens exposed to simulated pressurized water reactor (PWR) primary water were experimentally characterized in high temperature and high pressure water condition. And, the resistance to the flow accelerated corrosion (FAC) test was investigated to check the durability of plated layers in high-velocity water-flowing environment at high temperature. The plated surfaces were examined by using both scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS) after exposures to the condition. From this study, it is found that the corrosion resistance of electroless nickel-plated Alloy 600 is higher than that of electrolytic plating in 290 °C water.