真丝绸表面光接枝2-(双甲基胺)乙基甲基丙烯酸酯改性研究

真丝绸的染色性能差,是制约真丝绸市场竞争力的主要因素之一。在前人使用化学方法和高能辐射方法对真丝绸接枝共聚改性的研究基础上,本工作在不添加任何光引发剂或光敏剂的前提下,利用紫外光对真丝绸表面进行光化学接枝改性。详细研究了紫外光源类型、单体类型、单体浓度、光照时间、反应环境温度、表面活性剂、pH值等诸多因素对接枝率和相应接枝共聚物的物理化学性质的影响,探索接枝条件对接枝共聚物微观结构和性能的影响规律,并着重研究接枝单体、接枝条件与真丝绸染色性能的对应关系。     

狗牙釉质电子自旋共振剂量学的研究

对4组狗牙釉质样品分别进行不同剂量137Csγ射线的照射.使用电子自旋共振(Electron spin resonance,ESR)谱仪测量所有样品照射前的ESR固有信号强度,根据照射不同剂量后的ESR信号强度,研究不同剂量的γ射线照射后狗牙釉质所产生的ESR信号强度的变化.结果表明,137Cs γ射线照射前,狗牙釉质...     

掺杂型羟基磷灰石剂量学性能研究进展

电离辐射可在掺杂型羟基磷灰石中诱发自由基,利用电子自旋共振(ESR)技术检测自由基含量,可以进行辐射剂量测量。本文介绍掺杂型羟基磷灰石的剂量学特性及其研究现状,分析讨论其作为新型辐射剂量计材料的可行性。     

富勒烯乙二胺的抗辐射损伤性能

合成了一种水溶性富勒烯衍生物——富勒烯乙二胺,分别采用60 Co源和中子加速器等辐照装置,并结合红外光谱(FTIR)、电子自旋共振技术(ESR)和电喷雾质谱(ESI-MS)等表征手段,比较考察了富勒烯乙二胺与香兰素对受γ射线和中子等高能射线或粒子照射所产生自由基的清除性能。结果表明:对于经γ射线和中子辐照产生的自由基,所制得的富勒烯乙二胺均表现出了较好的抗辐射损伤特性;相同条件下对样品辐照所产生的自由基的清除性能明显优于市购的香兰素。     

自旋陷阱法研究γ射线照射胸腺嘧啶水溶液生成的自由基

本文用自旋陷阱法研究了γ射线照射胸腺嘧啶水溶液生成的自由基。含有胸腺嘧啶和自旋陷阱剂tNB(亚硝基特丁烧)的 H_2O或D_2O溶液经反复冰冻驱气后,用~(60)Coγ射线源在室温下照射,吸收剂量为1.3×10~5拉德。甲酸钠用来清扫辐照后水中形成的H和OH自由基,以便研究水合电子(e_(aq)~-)产生的自由基。瞬态胸腺嘧啶自由基被tNB陷获后,用电子自旋共振(ESR)谱仪测定。实验观察到三种胸腺嘧啶自由基。     

低温等离子体改性聚乙烯表面的自由基过程

以电子自旋共振波谱仪(ESR)为主要手段,研究了聚乙烯等五种聚合物等离子体改性过程中表面自由基的生成及转化。等离子体辐照的聚合物首先在表面生成烷基自由基,当与空气接触时,烷基自由基转化成过氧化自由基,在聚合物表面引入极性基因是通过过氧化自由基的反应完成的。     

2,2,6,6-四甲基哌啶-1-氧自由基对低温等离子辐射聚氨酯膜表面过氧自由基的研究

采用2,2,6,6-四甲基哌啶-1-氧自由基(2,2,6,6-Tetramethyl-1-piperidinyloxyl radical,TEMPO)法,测定了经氧气低温等离子体处理后聚氨酯膜表面过氧自由基的浓度,探讨了等离子轰击时间、等离子放电功率、在空气中放置时间等因素对等离子体处理后自由基浓度的影响.在经测定获得的自由基浓度较高的条件下,引发聚氨酯与丙烯酸的接枝聚合,验证了TEMPO法的可行性,讨论了聚合时间对接枝率的影响.丙烯酸在聚氨酯膜表面的接枝共聚由扫描电子显微镜得到确认.在等离子放电功率为600W,放电时间为180s时所测定的自由基浓度最高,相应的接枝率较高.实验结果表明,TEMPO法是一种有效的测定自由基浓度的方法.     

辐射引发的亚油酸和亚麻酸自由基产物及α-生育酚的辐射保护效应的ESR研究

用电子自旋共振波谱法,对在含氧条件下经过低温γ辐照的不饱和脂质亚油酸和亚麻酸产生的初级不稳定自由基,及其在程序升温过程中所产生的自由基变化进行了研究。由77K辐照并测定的ESR谱表明其初级不稳定产物为阴离子自由基和脂质长链上不饱和部分的抽氢自由基,在120 K附近所测得的ESR谱显示了脂质过氧自由基的波谱特征,随着温度继续上升,最后演变为戊二烯基自由基和α-碳抽氢自由基。亚油酸和亚麻酸与α-生育酚(摩尔比1:1)二元体系的ESR研究,揭示了α-生育酚对亚油酸和亚麻酸的辐射保护作用是基于氢原子转移机理。     

60Coγ射线急慢性照射对小鼠骨、牙和毛发ESR信号的影响

对昆明种雄性小白鼠给予不同剂量的急性或慢性60Co γ射线整体照射(剂量范围为0-3.0Gy),分离小鼠股骨、牙齿和毛发并进行前处理后,用电子自旋共振谱仪(ESR)测定各自的信号强度.结果表明,小鼠牙齿和毛发信号无特征性峰.小鼠股骨ESR信号呈现特征峰,无论是急性照射还是慢性照射,小鼠股骨ESR信号强度随着照射剂量的增大而增高,呈现良好的直线关系.保存在福尔马林溶液中的小鼠股骨,其ESR信号强度在保存7d时明显降低(p＜0.001),在室温干燥条件下保存453d的股骨ESR信号强度无明显改变.说明,小鼠股骨的最适保存条件为室温干燥.     

丙氨酸自由基剂量计

辐射加工技术已在工农业生产中得到广泛的应用,但是适合于这种量程范围的较简易的剂量测量手段还较少。 固体丙氨酸粉末经过辐照后,产生稳定的长寿命丙氨酸自由基。Bradshaw等在六十年代用ESR(电子自旋共振)方法测定了辐照诱发的丙氨酸自由基,并用作剂量计,以后这     

ESR signals from silk fabrics irradiated by UV -rays

ESR studies were done on UV-ray irradiated silk fabric samples at room temperature. Different types of UV lamps were used and similar ESR signals were observed. The results indicate that UV-rays can produce free radicals for graft-copolymerization of monomer onto silk fibers without external additives or co additives, Also, radicals in silk fabrics irradiated by UV-rays are purer than that irradiated by γ-rays. The study suggests that UV-lights may be a better tool to improve properties of silk fabrics by grafting monomers onto the polymer chains.     

Properties of radicals created by γ-ray irradiation of silk fabrics

The properties of radicals from γ-ray irradiated silk fabrics were studied by electron spin resonance method (ESR). The ESR spectra of silk fabrics irradiated in N2 showed a doublet at room temperature. The doublet became a singlet at g=2.0057 after placing the sample in air for 24 hours. This can be explained by formation of peroxide radicals. The radical concentration of the irradiated silk fabric and the decay rate of radicals are significantly affected by irradiation conditions, which include the absorbed dose, atmosphere, and water content of the silk fabric samples. However, no dose rate effect on the radical concentration was observed. The results are of help in our practice of property modification of silk products by radiation graft copolymerization.     

The effect of atmospheric pressure glow discharge plasma treatment on the dyeing properties of silk fabric

In this study, the effects of plasma treatment parameters on surface morphology, chemical constituent, dyeability and color fastness of silk fabric were investigated. Atmospheric pressure glow discharge plasma generated with different applied voltages(0 kV to 45 kV) was used to treat the surface of silk fabrics. C I Natural Yellow 3 was used to dye untreated and plasmatreated silk fabrics. The physical analysis based on scanning electron microscopy showed that the surface of silk fabrics was affected by plasma treatment. The chemical analysis was investigated with x-ray photoelectron spectroscopy and attenuated total reflection Fourier transform infrared spectroscopy. The results showed that the content of C 1s decreased with the increasing applied voltage, the content of N 1s and O 1s increased with the increasing applied voltage. The increasing K/S values represented that the dyeability of silk fabrics was improved after plasma treatment. The color fastness to dry and wet rubbing was decreased after plasma treatment.     

紫外线照射对羊毛织物表面理化性能的影响

利用相关表面性能测试方法对紫外线照射前后羊毛织物的表面化学组成、亲水性和微观结构进行表征。结果表明,紫外线照射过程可能是部分破坏了羊毛织物上具有疏水特性的胱氨酸和二硫键及非极性的C-C键,并同时提高了表面羟基、含N基团和C-O键的含量,使织物的亲水性能得到增强,且在紫外线照射羊毛织物静态水接触角降低、毛效提高的结果中得到证实;在低功率、短时间的处理条件下,紫外线照射羊毛织物引起的化学刻蚀未对纤维表面形貌及结晶区结构造成明显变化,仅略微提升了羊毛织物的粗糙程度。综合紫外线照射对羊毛织物表面理化性能的影响,认为该方法利于毛纺染整加工。     

丝绸的光引发丙烯酸羟丙酯接枝研究

以丙烯酸羟丙酯为单体,就丝绸的紫外光光化学接枝改性进行了系统研究。用红外光谱(FT-IR)和差示扫描量热法(DSC)等对光接枝产物进行了表征。探索了光照时间、单体浓度、pH值、温度、溶剂体系对接枝率的影响规律。研究表明,该方法较辐射接枝能获得更高的接枝率,且有无污染、设备简便、易于操作、均聚物较少等优点,不失为一种更有效的丝绸改性方法。     

Radiation effect of Apocynum fiber

1 Introduction Apocynum fiber is known for its softness, luster, coolness, good moisture absorption, and air perme-ability. Still, it has some faults such as smooth on sur-face, less curves, and inferior quality for spinning. The physical properties of Apocynum fiber was studied by Zhang Yi et al,[1] and Ce induced graft Apocynum fiber was studied by Chen Bowen et al.[2] Hassanpour and coworkers studied the modification of the cellu-lose.[3,4] We primarily focused on the concentration and…     

Spectroscopic analysis and mechanical properties of electron beam irradiated polypropylene/epoxidized natural rubber (PP/ENR) polymer blends

Polymer blends based on different ratios of polypropylene (PP) and epoxidized natural rubber (ENR) were prepared by melt extrusion into sheets. The PP/ENR blends were exposed to various dose of accelerated electrons. The formation of free radicals during and after electron beam irradiation was illustrated by electron spin resonance (ESR). Also, the effect of electron beam irradiation on the mechanical and structural morphology was investigated by stress-strain behavior and scanning electron microscope (SEM). The ESR spectra indicated the formation of alkyl and allyl radicals during electron beam irradiation and peroxyl radicals during the post effect. The rate of radical decay was found to be second-order kinetics. The improvement in mechanical properties and structural morphology was confirmed to be due to the effect of electron beam irradiation.     

γ射线辐照后木荷粉自由基的ESR和XPS分析

利用电子自旋共振波谱（ESR）和X射线光电子能谱（XPS）技术分别测量γ射线辐照后木荷粉体的自由基波谱和X射线光电子能谱。分析木荷粉体在60Coγ射线辐照下自由基的变化规律、化学组成和结构变化。结果表明：木荷自由基的光谱分裂因子g=2．0033,自由基的强度随吸收剂量按指数规律,I=1-e40增加;经过200kGy剂量的辐照后木荷表面O／C原子比稍有增加,C—C、C—H和C-O键含量增加,C=O双键含量减少,-O—C=O含量增加为原来的2．5倍,说明木材表面生成了一些含氧官能团,或碳的氧化态增高。     

60Co γ辐照下毛竹的自由基与化学结构的变化

绝干的毛竹粉体在⁶⁰Co γ辐照下产生自由基的同时还发生化学组成和结构的变化。利用电子自旋共振波谱（ESR）和X射线光电子能谱（XPS）技术分别测量γ射线辐照后毛竹粉体的自由基波谱和X射线光电子能谱。经测试,毛竹自由基的光谱分裂因子g=2.003 3,自由基的强度随吸收剂量按指数规律增加;经200 kGy剂量的辐照后毛竹表面的O/C原子个数比稍有增加,C-C和C-H含量增加,C-O和C[CDS1]O含量减少,-O-C[CDS1]O含量增加为原来的2.5倍,说明毛竹表面生成了一些含氧官能团或碳的氧化态增高。