交联淀粉微球对Cr^3＋的吸附研究

以淀粉为原料,N,N',-亚甲基双丙烯酰胺为交联剂,采用反相悬浮聚合得到了一种交联淀粉微球(CSM),利用红外光谱仪、SEM以及XRD对其结构进行表征.同时研究了CSM对Cr3+的吸附行为,研究了pH和时间对吸附性能的影响,并根据吸附等温线拟合出Langmiur方程和Freundlich方程.结果表明,淀粉微球表面粗糙多孔,交联后淀粉微球结晶性下降,吸附Cr3+后其结晶性进一步下降,淀粉微球对Cr3+的吸附行为很好地符合Langmiur方程和Freundlich方程,其相关系数分别为0.9949和0.9967.     

阴离子淀粉微球对Cr~(3+)的吸附及动力学研究

以阴离子淀粉微球为载体,研究了微球对Cr3+的吸附行为,考察了pH、时间、温度、初始浓度等因素对其去除率的影响及对Cr3+的吸附动力学特性,结果表明,其吸附最适pH值为7~9,在吸附作用的前60 m in对Cr3+的吸附速率较快,在一定的温度范围内,随吸附温度的升高,吸附量及去除率增大,初始浓度越小去除率越大;且求得吸附表观活化能为Ea=2.213 kJ/mol。     

新型淀粉基微球对Ni~(2+)的吸附行为及机理研究

以新型淀粉基微球为吸附载体,研究了微球对Ni2+的吸附性能,通过红外、X射线衍射仪对微球及其吸附产物进行表征。结果表明:淀粉基微球对Ni2+吸附等温线同时符合兰格缪尔和弗兰德里希等温方程;淀粉基微球对Ni2+的吸附为物理吸附过程。     

淀粉微球对Pb^2＋的吸附及动力学研究

以淀粉微球(CSM)为载体,研究了微球吸附Pb2+时pH,温度、溶液浓度对吸附量的影响及对Pb2+的吸附动力学特性,利用红外(FT-IR)、SEM和X射线衍射仪(XRD)对微球进行表征.结果表明,其吸附最适pH为5～6,在一定的温度范围内,随吸附温度的升高,吸附量增大;微球对Pb2+吸附行为符合Langmiur方程和Freundlich方程;且求得吸附表现活化能为Ea=2.210 kJ·mol-1.     

磁性淀粉微球对Ni(Ⅱ)吸附性能的研究

研究了磁性淀粉微球对Ni(Ⅱ)的吸附性能。考查了在常温条件下,反应时间、Ni(Ⅱ)的初始浓度、磁性淀粉微球的用量等对吸附性能的影响。探讨了磁性淀粉微球对Ni(Ⅱ)的吸附热力学和吸附动力学行为。结果表明:Ni(Ⅱ)为80mg/L,磁性淀粉微球用量为30mg时,在常温下经过80min的振荡吸附,磁性淀粉微球对Ni(Ⅱ)饱和吸附量达到11.69mg/g;吸附热力学表明磁性淀粉微球对Ni(Ⅱ)的吸附行为符合Freundlich方程;磁性淀粉微球对Ni(Ⅱ)离子的吸附过程可用准一级和准二级动力学模型进行模拟,但更符合二级动力学方程。     

交联淀粉微球对苯胺的吸附行为及机制探讨

以可溶性淀粉为原料,N,N′-亚甲基双丙烯酰胺(MBAA)为交联剂,采用反相悬浮聚合法合成了CSM(交联淀粉微球)。研究了CSM对苯胺的静态吸附行为,分析了其吸附热力学和动力学特性,测定了不同温度时的吸附等温线,并探讨了吸附机制。结果表明:在研究范围内,CSM对苯胺的吸附在60 min以后达到平衡,其饱和吸附量为4.62 mmol/g,并且其吸附行为同时符合Langmuir方程和Freundlich方程;CSM对苯胺的吸附是一个自发、放热、焓推动的物理吸附为主的过程。     

复合淀粉微球对铜离子的吸附及动力学研究

以复合淀粉微球为载体,研究其对Cu2+的吸附行为,考察了反应时间、pH值、反应温度、Cu2+的初始浓度等因素对吸附量的影响,并研究了吸附行为的动力学模型。结果表明,复合淀粉微球在120 min时可以达到对Cu2+吸附的平衡状态,静态吸附实验发现,在pH=6、温度35℃、Cu2+初始浓度0.10 mol/L时复合淀粉微球对Cu2+的吸附量较高。动力学实验研究表明,吸附行为可能更符合准二级动力学模型。     

阿司匹林载药淀粉微球吸附热力学和释药动力学的研究

以可溶性淀粉为原料,研究了淀粉微球在反相悬浮体系中不同温度下对阿司匹林的吸附行为,并考察其体外释放情况.结果表明：在实验条件范围内淀粉微球对阿司匹林的吸附量随着阿司匹林浓度的增加而增加.浓度相同时,温度越低,淀粉微球的吸附量也越大.吸附行为更符合Langmuir吸附模型,吸附为自发不可逆过程.总熵变是负值,焓变是主要的吸附驱动力.体外释放结果表明,阿司匹林淀粉微球聚合物在酸性介质中的释放行为更符合Higuchi方程,阿司匹林载药淀粉微球具有缓释作用.     

交联淀粉微球对Ni~(2+)的吸附性能研究

以可溶性淀粉为原料,N,N'-亚甲基双丙烯酰胺为交联剂,采用反相悬浮聚合得到了一种交联淀粉微球(CSM利用扫描电镜、红外光谱仪和X射线衍射仪对其结构进行表征.研究了在不同温度下CSM对Ni2+的静态吸附行为,并根据吸附等温线研究了吸附热力学性质,结果表明:在308～328K和研究的浓度范围内,CSM对Ni2+吸附行为符合Freundlich方程;CSM吸附Ni2+的吸附焓变△H、吸附自由能变△G、吸附熵变△S均为负值,表明吸附是一个自发的、放热的熵减小过程,适当降低温度有利于吸附.热力学性质分析结果表明CSM主要通过物理吸附方式吸附Ni2+.     

淀粉/二氧化硅微球对水中重金属离子的吸附性能

利用土豆淀粉、玉米淀粉、正硅酸乙酯为原料,氨水为催化剂,通过溶胶-凝胶法制备了淀粉/二氧化硅复合微球,研究了该复合微球对水中铅离子的吸附性能。结果表明,在弱碱性条件下,淀粉/二氧化硅复合微球对水中铅离子表现出良好的吸附性能,其对铅离子的吸附行为符合Langmuir模型和Freundlich模型,对铅离子的饱和吸附量为31.34 mg/g。动力学研究表明,淀粉/二氧化硅复合微球对铅离子的吸附符合拟二级动力学模型,在淀粉/二氧化硅复合微球的活性点上的化学反应为吸附控制步骤。     

Mechanically activated starch magnetic microspheres for Cd(Ⅱ) adsorption from aqueous solution

Magnetic starch microspheres(AAM-MSM) were synthesized via an inverse emulsion graft copolymerization by using mechanically activated cassava starch(MS) as a crude material, acrylic acid(AA) and acrylamide(AM) as graft copolymer monomers, and methyl methacrylate(MMA) as the dispersing agent and used as an adsorbent for the removal of Cd(II) ions from aqueous solution. Fourier-transform infrared spectroscopy(FT-IR), X-ray photoelectron spectroscopy(XPS), scanning electron microscopy(SEM), and vibrating sample magnetometry(VSM) were used to characterize the AAM-MSM adsorbent. The results indicated that AA, AM, and MMA were grafted to the MS, and the Fe_3 O_4 nanoparticles were encapsulated in the AAM-MSM adsorbent microspheres.The adsorbent exhibited a smooth surface, uniform size, and good sphericity because of the addition of the MMA and provided more adsorption sites for the Cd(II) ions. The maximum adsorption capacity of Cd(II) on the AAM-MSM was 39.98 mg·g~(-1). The adsorbents were superparamagnetic, and the saturation magnetization was 16.7 A·m~2·kg~(-1). Additionally, the adsorption isotherms and kinetics of the adsorption process were further investigated. The process of Cd(II) ions adsorbed onto the AAM-MSM could be described more favorably by the pseudo-second-order kinetic and Langmuir isothermal adsorption models, which suggested that the chemical reaction process dominated the adsorption process for the Cd(II) and chemisorption was the rate-controlling step during the Cd(II) removal process.     

新型淀粉基微球对Cu~(2+)、Pb~(2+)吸附性能的研究

研究了新型淀粉基微球对Cu2+、Pb2+的吸附性能,结果表明,淀粉基微球对Cu2+的吸附能力强于Pb2+,对Cu2+、Pb2+的吸附率可达到85%以上,是一种有效处理重金属离子废水的处理剂。     

淀粉接枝共聚物微球的合成研究

用V(环己烷)∶V(淀粉溶液)=4∶1构成反相悬浮体系,m(Span60)∶m(Tween60)=2∶1复配为分散剂,在60℃下以K2S2O8-NaHSO3引发N,N’-亚甲基双丙烯酰胺(MBAA)与淀粉的接枝共聚,制备了淀粉接枝共聚物微球。正交实验表明,合成共聚微球的较优工艺条件为:淀粉液浓度20%,引发剂用量0.2 g,MBAA用量0.4 g,油水比为3∶1,乳化剂用量1.0 g。用SEM和粒度分析仪对微球形貌和粒度分布进行了研究,用FT-IR对其结构进行了表征,用XRD,TGA对其物性进行了分析。结果显示,共聚物微球形态圆整,平均粒径50.2μm,微球中存在酰氨基结构,与淀粉颗粒相比,结晶度降低,热稳定性提高。     

Utilization of some starch derivatives in heavy metal ions removal

Three types of starch derivatives containing amide groups were used in removal of heavy metal ions from their solutions. These starch derivatives were poly(acrylamide)–starch graft copolymer, carbamoylethylated starch, and starch carbamate. The different factors affecting metal ion adsorption on these substrates, such as pH, metal ion concentration, type of starch derivatives, treatment time, and temperature, were studied. Results obtained indicate that the poly(acrylamide)–starch graft copolymer was a selective adsorbant for Hg²⁺ at pH 0.5–1. The adsorption values ofdifferent metal ions on these starch derivatives follow the order of Hg²⁺ > Cu²⁺ > Zn²⁺ > Ni²⁺ > Co²⁺ > Cd²⁺ > Pb²⁺. The adsorption values depend upon pH, type of starch derivative, treatment duration, and temperature. The adsorption efficiency percentage of metal ions on the three substrates follows the order of carbamoylethylated starch > poly(acrylamide) − starch graft copolymer > starch carbamate. © 1998 John Wiley & Sons, Inc. J Appl Polm Sci 69: 45–50, 1998     

木薯淀粉磁性微球的结构表征及其对溶菌酶的吸附性能

磁性微球是高分子材料与磁性物质通过一定作用复合而成的一类具有特殊功能的磁性高分子微球。以木薯淀粉为原材料,复合共沉淀法制备的改性磁流体Fe₃O₄,采用两步法(化学交联法)制备木薯淀粉磁性微球。利用傅里叶变换红外光谱仪、X射线衍射仪、同步热分析仪、扫描电镜、激光粒度仪、磁天平等对其性能及结构进行表征并研究其对溶菌酶的吸附行为。通过单因素法考察磁性微球用量、溶液pH值、吸附温度、吸附时间对吸附率的影响,并采用准一级动力学模型和准二级动力学模型研究其吸附动力学。结果表明:制备的木薯淀粉磁性微球Fe₃O₄含量为19.71%,D₅₀(中位径)为15.40μm,磁化率为1.571×10^-3cm³/g,形貌规整;在微球用量为1.25g,溶液pH=10,吸附温度为25℃,吸附时间为80min时,微球对溶菌酶的吸附率最高,达到84.67%。以相关系数R²为参考,准二级动力学模型(R²=0.99993)较准一级动力学模型(R²=0.99174)、颗粒内扩散模型(R²=0.69996)能更好描述木薯淀粉磁性微球对溶菌酶的吸附行为。     

Preferential adsorption of bovine fibrinogen dimer onto polymer microspheres having heterogeneous surfaces consisting of hydrophobic and hydrophilic parts

The adsorption onto polymer microspheres of bovine fibrinogen (BFb) containing both dimeric and monomeric species was examined using various homopolymer, copolymer, and poly(2-hydroxyethyl methacrylate)/polystyrene composite microspheres which were produced by the emulsifier-free (seeded) emulsion polymerization technique. The preferential adsorption of the BFb dimer was clearly observed in an optimum region of the surface hydrophilicities of the polymer microspheres. The preferential adsorption of the BFb dimer onto the composite polymer microspheres having heterogeneous surfaces with both hydrophilic and hydrophobic parts was more remarkable than that onto the homopolymer and copolymer microspheres having homogeneous surfaces. The behavior is discussed in comparison with those for bovine serum albumin and human γ-globulin.     

降解淀粉与乙烯基类单体接枝聚合物的合成及应用

适当降解的玉米淀粉与乙烯基类单体在引发剂作用下通过接枝聚合得到了改性淀粉鞣剂。当体系中w (降解淀粉 ) =10 %、w (乙烯基类单体 ) =2 0 %、引发剂质量为反应物质量的2 .0 %、反应温度为 5 0℃、反应时间为 1 5h时所得聚合物的接枝百分率为 87%、接枝效率为94%及接枝频率为 43。用其预鞣时可减少铬鞣剂用量 30 %～ 5 0 % ,铬鞣废液中铬含量降低到 ρ(Cr2 O3) =0 .2 6g/L ,用其复鞣时所得成革的选择填充性显著。成品革丰满柔软 ,粒面细腻。