核孔膜孔径测量和过滤效果研究

利用兰州重离子加速器提供的25 MeV·u~(-1) ~(86)Kr~(26+)离子辐照厚度为12μm和25μm的聚对苯二甲酸乙二酯(Poly(ethylene terephthalate),PET)薄膜,注量分别为1×10~6 ions·cm~(-2)和5×107 ions·cm~(-2)。将辐照后的PET薄膜浸入5 mol·L~(-1)、60oC的NaOH溶液蚀刻,制得不同孔径的核孔膜样品。分析了测厚法、光学显微镜观察法和泡点法三种孔径测量法的优劣,实验对比结果表明,对于孔径小于1μm的纳米孔径核孔膜,适合利用泡点分析法测量有效截留孔径,测量误差小于5%;对于孔径大于3μm的微米孔径或直筒孔核孔膜,优先选择光学显微镜观察法测量表面孔径,测量误差小于10%。制备孔径为2μm和450 nm的核孔膜样品,用其进行黄河水过滤,探究过滤效果。进一步证明微米孔径核孔膜去除水样中一般颗粒物有明显效果(微粒数目平均减少99.12%),450 nm孔径或更小孔径的核孔膜可绝大部分清除水样中的细菌(微粒数目减少99.90%)。实验结果对今后核孔膜孔径的测量和定标及水质净化具有参考意义。     

PET核孔膜蚀刻速率影响因素的研究

核孔膜是通过重离子照射薄膜后进行化学蚀刻所得到的高性能过滤材料,蚀刻速率是影响高质量核孔膜制备的重要因素。本文探讨了不同蚀刻液浓度、温度以及重离子辐照能量对蚀刻速率的影响。利用140 MeV的32S离子在室温和真空条件下对4层堆叠的PET(polyethylene terephthalate)薄膜进行了辐照。在对辐照样品进行化学蚀刻期间采用电导法确定了径迹蚀刻速率Vt。结果表明:蚀刻速率与蚀刻温度呈指数相关,随蚀刻液浓度增加而线性增大;径迹蚀刻速率随能量损失率(离子能损)增大。研究确定,在入射32S能量为1.6 MeV·u-1时,NaOH浓度为1mol·L-1、蚀刻温度为85°C时最有利于形成圆柱形微孔。     

电导法研究紫外光预辐照对核孔膜径迹蚀刻的影响

利用紫外光辐照聚碳酸酯（PC）离子径迹膜,研究光辐照对于核孔膜蚀刻过程的影响。实验结果显示,紫外光照射对核孔膜的蚀刻有着重要的作用,它可以有效地增加径迹的蚀刻速率,并且径迹蚀刻速率随紫外光照时间的增加呈线性增长关系,此现象是由于光降解作用引起的。本文还介绍了用于监测核孔膜蚀刻过程的电导测量方法,利用此方法可以得出核孔膜径迹蚀刻速率、孔径随蚀刻时间变化等关系。     

纳米孔径重离子微孔膜的制备

应用中国原子能科学研究院HI 13串列加速器产生的重离子32S和79Br轰击聚对苯二甲酸乙二醇酯（PET）薄膜,再对薄膜进行化学蚀刻处理使由重离子辐照损伤产生的潜径迹形成微孔,制备出孔径为100～900nm的重离子微孔膜。为增加径迹蚀刻速率与体蚀刻速率之比,化学蚀刻前采用紫外光辐照薄膜。蚀刻过程中采用电导蚀刻法监测膜孔径生长过程。对32S和79Br辐照制备的重离子微孔膜进行了比较,79Br离子辐照制备的微孔膜与32S离子辐照制备的微孔膜相比,孔型圆整,锥角更小;在制备纳米微孔膜方面79Br离子优于32S离子。     

聚酯膜在NaOH溶液中的蚀刻速率

木文研究了蚀刻剂对聚酯(PET)基膜的蚀刻速率及径迹蚀刻速率,以制备精确孔径的核孔膜。测定了PET基膜在不同浓度、温度的NaOH溶液中的蚀刻速率,经回归得到它们之间的经验关联式,提出了几种增大PET膜径迹蚀刻速率的有效方法。     

HI-13串列加速器重离子辐照核孔膜的实验研究

扼要介绍了几年来在HI-13串列加速器上开展的辐照核孔膜的实验研究的一些结果,包括重离子种类的选择,能量和束流强度对核孔膜指标的影响以及提高辐照均匀性的措施等。实验用膜材为10～30μm厚PET(聚酯)薄膜,束流为3.5～4.5MeV/N的S束,核孔膜孔密度为10~5～10~8cm~(-2),均匀性为80％左右。     

核孔膜在茶汤过滤中的应用

利用兰州重离子加速器提供的25 MeV·u~(-186)Kr~(26+)离子辐照的聚对苯二甲酸乙二醇酯薄膜蚀刻制备了多种规格核孔膜;针对饮茶时残存杯底的茶垢,用核孔膜开展了一系列茶汤过滤实验及滤后分析。过滤方法为螺旋平板小试仪上进行的死端过滤。对过滤后的茶汤和滤后膜表面分别进行了激光粒度、浊度色度、扫描电镜等分析,证明对茶汤除杂的有效性,观察截留的颗粒物形态;用流速测定的方法记录了滤膜的流速衰减过程;对流速和过滤效果俱佳的15μm核孔膜进行了在水壶中冲泡的耐久性测试,提出了核孔膜污染后可能的清洗方法。本文探讨了过滤过程初始流速对滤膜寿命的影响,指出控制初始流速是一种核孔膜过滤的优化操作,具有一定参考意义。     

HI-13串列加速器重离子辐照核孔膜的实验研究

扼要介绍了几年来在HI-13串列加速器上开展的辐照核孔膜的实验研究的一些结果,包括重离子种类的选择,能量和束流强度对核孔膜指标的影响以及提高辐照均匀性的措施等。实验用膜材为10～30μm厚PET(聚酯)薄膜,束流为3.5～4.5MeV/N的S束,核孔     

紫外光照射对聚丙烯核孔膜蚀刻的影响

采用主峰波长为365 nm的紫外光灯对经³²S离子和⁷⁹Br离子辐照过的16 μm厚的聚丙烯（PP）膜正反面分别敏化6、8、10、12 h。选取重铬酸钾和硫酸的混合溶液作为蚀刻液对样品膜进行蚀刻,采用电导法监测电流随蚀刻时间的变化,确定不同敏化时间下样品膜的导通时间。同种离子辐照后敏化时间越长,膜导通时间越短,径迹蚀刻速率也越快,且辐照离子的原子序数越大,该影响越明显。相同敏化时间（12 h）和蚀刻条件下,³²S离子辐照后膜的导通时间是⁷⁹Br离子辐照后的4.8倍。     

聚酯在红外区的反射性能研究

用串列加速器提供的^32S离子（能量160MeV，流强20nA）辐照厚度为20和50μm的聚酯膜。用不同的蚀刻溶液和敏化剂敏化过程，得到孔径为1和3μm的圆柱形和圆锥形的径迹孔。在红外区1．3-10．0μm波段测量反射率，在3．3-10．0μm波段反射率小于5％。     

Radiation grafting of NIPAAm on PVDF nuclear track membranes

Polymer surface modifications are obtained by the application of radiation treatments and other physico-chemical methods: fragment fission (ff) or ion implantation, etching and grafting procedure. Poly vinylidene fluoride (PVDF) foils were irradiated during different times to produce pores of different diameters through the foils. In this way, nuclear track membranes (NTM) were produced with different track diameters and track numbers. Active sites were formed using a γ-ray Co-60 source and then contacted with N-isopropylacrylamide (NIPAAm) to obtain a graft copolymer that responds to environmental conditions. The present work shows the grafting yield as a function of: γ-dose, NIPAAm concentration, pore diameter, track density, etc.     

PET核孔膜制备纳米钯及其形貌观测

采用径迹蚀刻的聚酯（PET）膜制作核孔膜模板,辅助电化学沉积法制备了纳米钯。利用扫描电子显微镜（SEM）和能量色散X射线光谱仪（EDX）对纳米钯的形貌和成分进行了表征。结果显示,在沉积电位为-0.65 V时,此法制备的纳米钯颗粒均匀,且呈阵列分布,长径比分布范围为5～70。     

Study on Transmission of Near-infrared Light Through Polyester Films Modified by Nuclear Pores

Polyester membranes were irradiated by energetic ^32S ion beams from the HI-13 tandem accelerator, and then etched by NaOH solutions with different concentration, temperature, and etching time. These nuclear pore-modified membranes were studied on pore size, pore shape, and the transmission properties for near infrared light. Preliminary results show that the membranes produced with optimized pore density and etching conditions have higher transmission rate.     

Developing anti-metallic contamination polyester membranes with nuclear pore technique

Surface contamination by conducting materials,metals in particular,is one of the important causes for electric breakdown of insulators under high voltage.In order to explore the feasibility of nuclear track modification for anti-metallic contamination,polyester membranes with different thickness were bombarded by 32S ions from the HI-13 tandem accelerator of CIAE.The tracks formed on the surface of the membranes were etched under different conditions.The insulating capability of the treated membranes was evaluated by using silver coatings to simulate the surface metallic contamination.The results indicated insulators with the surface modified by nuclear pore technique have an improved capability of anti-contaminatiun of metals.The sample with 144 nm Ag coating is not breakdown under 1000 V.     

聚丙烯核孔膜化学蚀刻工艺研究

探讨了蚀刻剂中重铬酸钾浓度、硫酸浓度及蚀刻温度、蚀刻时间等因素对聚丙烯膜基体蚀刻速率的影响；建立了基体蚀刻速率与重铬酸钾浓度，硫酸浓度、蚀刻温度的数学关联式；并选择一定的蚀刻条件对辐照过的聚丙烯膜进行蚀刻，得到了预期孔径的聚丙烯核孔膜。     

Etched heavy ion tracks in polycarbonate as template for copper nanowires

30 and 40 μm thick polycarbonate foils were irradiated with Au¹⁹⁷ and Pb²⁰⁸ ions of kinetic energy 1–2 GeV with fluences between 10⁶ and 10⁹ ions/cm². The latent tracks generated by the heavy ions were chemically etched providing membranes with cylindrical pores of diameters between 30 and 200 nm. These membranes have been used as templates for the creation of metallic nanowires of very high aspect ratio. A thin metal film deposited on one side of the membrane acted as cathode in the two-electrode electrochemical cell, while a copper cone served as anode. The wires were grown potentiostatically. The electrochemical process was monitored by registering chronoamperometric curves for different cathode overvoltages, temperatures and concentrations of the electrolyte. Under suitable conditions, single-crystalline needles were produced. The morphology and crystallinity of the copper nanowires were studied by means of scanning electron microscopy (SEM), transmission electron microscopy (TEM) and X-ray diffraction.     

电子束刻蚀聚碳酸酯制备微孔分离膜

以电子束刻蚀技术和聚碳酸酯(Polycarbonate,PC)材料本身的辐照裂解特性,结合微孔掩膜和溶液氧化腐蚀的方法,成功制备了具有规则垂直孔道的PC微孔分离膜。用乌氏粘度计、凝胶渗透色谱仪、仪和傅里叶红外光谱分析仪表征辐照PC的结构和性能变化。结果表明,PC材料的黏均相对分子量、数均分子质量、玻璃化温度、黏均聚合度均随吸收剂量的增加而下降;红外分析表明PC在电子束照射下发生主链断裂;动力学分析表明其辐照降解属于无规降解类型,为电子束刻蚀制备PC微孔分离膜技术提供了理论依据。