二甲基丙烯酸聚乙二醇酯的原子转移自由基交联聚合

对二甲基丙烯酸酯进行原子转移自由基（ATRP）交联聚合,通过示差扫描量热方法研究了过渡金属卤化物、配体和反应温度对二甲基丙烯酸酯ATRP交联聚合动力学的影响.结果表明CuBr、CuCl和FeCl 2可以催化二甲基丙烯酸酯的ATRP交联聚合,催化活性的顺序从大到小为FeCl 2、CuBr、CuCl.配体对二甲基丙烯酸酯ATRP交联聚合具有较大的影响,TEDETA作为配体时聚合速率最快,双键转化率最高.升高温度可以提高聚合反应速率和双键转化率,其表观活化能为81.5 kJ/mol.     

含负折射率介质布拉格微腔的缺陷模

研究了由正和负两种折射率介质交替排列构成的一维光子晶体布拉格微腔的透射谱和缺陷模性质,并将传输矩阵各矩阵元在中心频率附近采用泰勒展开并取一级近似,得到了中心频率附近缺陷模的透射率公式和品质因子公式。研究结果表明:一级近似法能很好地解释由于缺陷层厚度变化而引起的中心频率附近缺陷模频率变化的规律,缺陷模品质因子公式与数值计算结果十分吻合;处于中心频率处的缺陷模具有较高的品质因子,增大缺陷层厚度和布拉格镜周期数可提高缺陷模的品质因子。     

异臂星状聚甲基丙烯酸甲酯-苯乙烯的合成与表征

以α-溴代异丁酸叔丁酯(BIBTB)为引发剂,CuBr/Bpy为催化体系引发甲基丙烯酸甲酯(MMA)聚合得到大分子引发剂PMMA-Br,利用电荷转移络合物效应以PMMA-Br引发支化单体二苯甲烷双马来酰亚胺(BMI)和苯乙烯就地优先生成双官能团大分子引发剂再继续引发苯乙烯得异臂星状聚合物。采用1H-NMR、GPC、MALLS、FT-IR和DSC等方法对聚合反应过程、聚合物及其水解产物进行分析测试。研究结果表明:利用电荷转移络合物效应就地生成双官能团大分子引发剂合成异臂星状聚合物是可行的。     

The effect of annealing and gold deposition on the performance of magnetoelastic biosensors

Magnetoelastic materials have a mass-sensitive, characteristic, resonant frequency that make them an ideal choice for application as the platform for a biosensor. The biosensor is formed by immobilizing a bio-molecular recognition element directly onto the surface of the magnetoelastic material. When exposed to the analyte, this bio-molecular recognition element binds the target species (spore or bacteria of interest), thereby increasing the mass and decreasing the resonance frequency of the sensor. This change in characteristic resonance frequency can be determined by monitoring remotely the magnetic flux in response to an applied, time varying, magnetic field with a pick-up coil. However, the environmental stability and bioactivity of the biosensor platform material are very important to performance of the overall biosensor. This research investigates the effects of annealing and deposition of a gold layer on the environmental stability and detection sensitivity of a magnetoelastic biosensor platform. The results show that deposition of a gold layer by sputtering additionally improved bioreactivity while maintaining a balance of environmental stability and detection sensitivity. Two annealing steps in a vacuum oven, one before and one after gold deposition, can effectively increase the magnetoelastic platform's environmental stability, as well as the Q-factor of the resonance signal.     

Preparation of hyperbranched copolymers of maleimide inimer and styrene by ATRP

Novel hyperbranched copolymers were prepared by the atom transfer radical copolymerization of N-(4-α-bromobutyryloxy phenyl) maleimide (BBPMI) with styrene in 1-methyl-2-pyrrolidone (NMP) using the complex of CuBr/2,2′-bipyridine as catalyst. The copolymerization behavior was investigated by comparison of the conversion of double bond of BBPMI determined by ¹H NMR with that of styrene. The hyperbranched structure of resulting copolymers was verified by gel permeation chromatography (GPC) coupled with multi-angle laser light scattering (MALLS). The influences of dosage of catalyst and monomer ratio on the polymerization rate and structure of the resulting polymers were also investigated. The glass transition temperature of the resulting hyperbranched copolymer increases with increasing mole fraction of BBPMI, f_BBPMI. The resulting copolymers exhibit improved solubility in organic solvents; however, they show lower thermal stabilities than their linear analogues.     

室温ARB技术制备超细晶铜板的研究

通过等效应变、轧制压下量和轧制温升的理论分析以及纯铜的变形试验，研究室温累积叠轧变形（accumulative roll bonding，ARB）制备超细晶铜板。结果表明，室温ARB变形可以获得超细晶板带材，纯铜6道次ARB变形后．平均晶粒大小约为0．5μm。     

Enhanced magnetoelectrical coupling in cobalt ferrite/lead lanthanum zirconate titanate 0-3 composites through phase boundary modification

We have developed a processing technique for producing cobalt ferrite (CFO)/lead lanthanum zirconate titanate (PLZT) 0-3 composites with enhanced piezoelectric, ferroelectric and magnetoelectrical (ME) coupling properties. It includes modifying the phase boundary with zirconia barrier layer and decreasing the sintering temperature with Li₂O + 0.5Bi₂O₃ additives. The CFO/PLZT 0-3 composites were successfully fabricated via conventional co-firing procedures. The obtained 0-3 composite ceramics can withstand a DC electric field of 6 kV mm⁻¹. The effects of CFO/PLZT ratio on the crystalline structure, piezoelectric, ferroelectric, dielectric and M–E properties were investigated. The M–E coefficients of the composites with CFO:PLZT volume ratio of 14.4:85.6, 27.4:72.6 and 39.3:60.7 were found to be 31, 52 and 143 mV (Oe cm)⁻¹ at 100 kHz under a bias field of ∼1 kOe.     

二甲基丙烯酸酯原子转移自由基聚合行为和交联结构

通过差示扫描量热法研究了二甲基丙烯酸酯原子转移自由基(ATRP)交联聚合的反应动力学,用平衡溶胀法跟踪了交联结构的形成和发展。结果表明,二甲基丙烯酸酯ATRP的聚合速率比通常自由基聚合慢得多,不出现明显的自加速效应,交联网络结构更疏松。单体双键之间的链段长度对其ATRP交联聚合行为和交联结构有较大影响,随链段长度增加,聚合反应速率放慢,双键的转化率下降,交联网络结构更加均匀和疏松。     

氯化聚氯乙烯的热稳定性配方研究

利用刚果红法研究热稳定剂三盐、两盐、钙锌复合稳定剂、有机锡、硬脂酸钙对氯化聚氯乙烯（CPVC）的稳定作用，研究结果表明：铅盐类稳定剂稳定效果较好，各种稳定剂之间具有协同效应。在考虑环保要求的基础上确定较佳的CPVC配方。     

残余氯在等离子体增强化学气相沉积TiN膜中的偏聚过程研究

通过分析等离子体增强化学气相沉积(PECVD)的特点,对残余氯的存在机制、等离子体场中离子轰击对氯在TiN膜内分布的影响作了进一步的讨论。运用经典偏聚理论,根据空位、位错特点,建立了PECVD过程中离子轰击促进氯向晶界、微孔表面等界面处偏聚的模型,从而充满地解释了文献中的有关实验现象。