添加剂对纳米碳酸钙形貌与粒度的影响

采用碳化法和复分解法,通过选用不同添加剂及控制其添加量制备了不同形貌和粒径的纳米碳酸钙。用TEM、SEM对所得产物的形貌和尺寸进行了表征。结果表明,当柠檬酸的添加量为0.25%~0.75%（质量分数,下同）时,可实现对纳米碳酸钙颗粒粒径的调控,并选用硬脂酸钠作为表面改性剂对其进行改性,改性后的纳米碳酸钙颗粒更大,形状更规整,分散性更好;当季戊四醇添加量为0.1%~10%时,分别制备出了不同粒径的球形和立方形纳米碳酸钙颗粒。初步探讨了有机酸类、糖类和醇类对合成纳米碳酸钙的影响效果和作用机理。     

纳米碳酸钙的制备及表面改性技术

综述了纳米碳酸钙的制备方法及其表面改性技术,并对纳米碳酸钙的发展前景进行了展望。纳米碳酸钙的制备分为碳化法和复分解法两类,其中碳化法可分为间歇鼓泡碳化法、连续喷雾碳化法和超重力碳化法三种。纳米碳酸钙的表面改性技术目前主要有有机物表面处理、高能表面处理和无机物改性三种方法。     

填料碳酸钙的制备及其形状与晶型控制研究进展

介绍了碳酸钙研究的新进展，主要讨论了普通碳酸钙，碳酸钙晶须和纳米碳酸钙的制备方法和机理，以及碳酸钙晶体的形状与晶型控制。     

纳米碳酸钙合成研究

采用传统的鼓泡碳化法，用50℃热水快速消化石灰，精制石灰乳冷却到20℃以下碳化，制备纳米碳酸钙。研究了碳化过程中粘度和pH的变化，以及陈化和添加晶形控制剂对纳米碳酸钙晶形的影响。通过陈化一二次碳化法制备了晶形比较完整的纳米碳酸钙，从而降低了纳米碳酸钙的吸油量。通过添加不同的晶形控制剂，可以制备立方体形、立方柱形、棒状和菱形纳米碳酸钙。     

不同粒度纳米碳酸钙的可控制备

不同粒度的纳米碳酸钙具有不同的特性和应用范围,目前不同粒度纳米碳酸钙的可控制备方法还未见报道。以氯化钙、碳酸铵为原料,以乙醇、柠檬酸和焦磷酸钠为分散剂,采用复分解法研究了不同制备条件对纳米碳酸钙粒径的影响规律,在此基础上制备出平均粒径为17~71 nm的碳酸钙,并对其进行了表征。实验结果表明,所制备的纳米碳酸钙均为球霰石型,纯度很高,而且形貌近似球形。制备条件对纳米碳酸钙的粒径有显著的影响：随着反应温度升高,纳米碳酸钙的粒径减小;随着氯化钙滴加时间的增加,纳米碳酸钙的粒径增大;随着反应物浓度的提高,纳米碳酸钙的粒径先减小后增大;当分散剂为柠檬酸和焦磷酸钠的混合溶液时所得纳米碳酸钙的粒径最小,当分散剂为乙醇和焦磷酸钠的混合溶液时所得纳米碳酸钙的粒径最大。利用这些影响规律通过控制制备条件可以实现所需粒径纳米碳酸钙的可控制备。     

碳酸钙产品及其展望

介绍几种碳酸钙产品:轻质碳酸钙、重质碳酸钙、活性碳酸钙、纳米碳酸钙,并且从理化性质、制备方法、颗粒形状以及应用等方面对重质碳酸钙与轻质碳酸钙进行了比较,并对轻质碳酸钙、重质碳酸钙、纳米碳酸钙三者的生产工艺以及发展前景作了简单介绍。     

聚丙烯/无机粉体/异形纤维复合材料的制备

以聚丙烯为聚合物基体,以纳米碳酸钙为无机组分,采用聚对苯二甲酸乙二醇酯(PET)纤维,纤维截面形状分别为圆形、扁平形和三角形,通过熔融共混的方法制备了聚丙烯/纳米碳酸钙/异形纤维复合材料,并采用不同的改性剂对纳米碳酸钙进行表面改性,通过扫描电子显微镜观察了纳米碳酸钙的分散情况,重点分析了聚丙烯/纳米碳酸钙/异形纤维复合材料的结构与性能的关系。结果表明,硅烷偶联剂对碳酸钙表面有机化处理的效果好于硬脂酸;纤维截面形状不同对复合材料的增强效果也不同,其中比表面积最大的三角形纤维增强效果最佳;当纳米碳酸钙的含量为3%(质量分数,下同)(2%硅烷偶联剂处理)、三角形PET纤维的长径比为80、含量为2%(体积分数,下同)(4%硅烷偶联剂处理)时,制得的聚丙烯/纳米碳酸钙/异形纤维复合材料的屈服强度比纯聚丙烯提高近21%,弹性模量提高了约82%。     

纳米碳酸钙的制备及表征

研究了以氧化钙和二氧化碳为原料,化学法制备纳米碳酸钙的工艺条件、添加剂的影响及形态。结果表明:中间体氢氧化钙的初始浓度、二氧化碳的流量、反应温度、搅拌速度及添加剂等在控制制备纳米碳酸钙颗粒的形状和尺寸中均十分重要。透射电镜观察结果表明:通过控制反应及添加剂,可以得到尺寸规整的链锁形、纺锤形和球形纳米碳酸钙。表面能谱证实产品为高纯的碳酸钙。X射线衍射和电子衍射的结果进一步表明:所制纳米碳酸钙均属方解石型六方晶系,a0=0.498 9 nm,c0=1.706 2 nm;为多晶结构。     

纳米碳酸钙及其在塑料高性能化改性中的应用

介绍了不同晶形的纳米碳酸钙的特性、制备方法及其表面处理技术，简述了各种纳米碳酸钙改性塑料的制备方法，对纳米碳酸钙在聚氯乙烯、聚乙烯、聚丙烯等塑料的高性能化改性中的应用进行了综述，本文还指出纳米碳酸钙应用于塑料改性中存在的问题。     

电石渣制备高附加值碳酸钙的研究进展

电石渣制备碳酸钙可实现电石渣的高附加值利用,是实现电石行业可持续发展的有效途径。本文总结了电石渣制备碳酸钙的方法,着重介绍了电石渣中钙的提取和碳化两个主要工艺过程。综述了电石渣在制备轻质碳酸钙、纳米碳酸钙及其表面改性和晶型控制方面的研究进展。分析认为,氯化铵浸取CO_2碳化工艺易于实现浸取剂的循环利用,同时又能利用废气中的CO_2,具有较大的利用潜能和广阔前景。在电石渣制备碳酸钙的过程中,可以同时实现纳米碳酸钙的表面改性,并通过控制碳化温度、加入添加剂等实现晶型控制,制得不同晶型和形状的碳酸钙产品。电石渣资源化应用制备碳酸钙,呈现出从低附加值向高附加值发展的趋势。未来电石渣资源化利用制备碳酸钙应进一步完善循环工艺,并深入进行碳酸钙的超细化、表面改性化和晶型控制研究。     

Mechanical properties and morphologies of polypropylene/single‐filler or hybrid‐filler calcium carbonate composites

Three types of polypropylene (PP) with different intrinsic toughness were used to study the mechanical properties and morphologies of the PP composites filled with single‐filler and hybrid‐filler of calcium carbonate particles. The calcium carbonate particles used were with average particle sizes of 25 μm (CC25), and 0.07 μm (CC0.07), respectively. A hybrid‐filler CaCO₃ named CC25/CC0.07 was used as a mixture of CC25 and CC0.07 (CC25/CC0.07 weight ratio = 1:1). It was found that the type of PP and the particle size of inorganic filler were the two important factors for the determination of mechanical properties of the composites. And the general mechanical properties of the composites filled with hybrid‐filler CaCO₃ were better than those of the composites filled with single‐filler CaCO₃, but the synergistic hybridization effect of the hybrid‐filler CaCO₃ did not exist. The major toughening mechanism of the PP/CC25 composites was the cavitation of the matrix caused by CC25, and the major toughening mechanism of the PP/CC0.07 composites was the pinning effect introduced by CC0.07. For the PP/CC25/CC0.07 composites, the cavitation of the matrix caused by CC25 and the pinning effect introduced by CC0.07 existed simultaneously. And when the intrinsic toughness of the matrix was large enough, the major factor to toughen PP was the pinning effect introduced by CC0.07, otherwise the major factor to toughen PP was the cavitation of the matrix caused by CC25. POLYM. ENG. SCI., 47:95–102, 2007. © 2007 Society of Plastics Engineers     

纳米氧化铝制备方法研究进展

纳米氧化铝作为一种重要的纳米材料,在陶瓷材料、催化剂载体等领域有着广泛的应用.首先介绍了纳米氧化铝的主要形态,然后分别对纳米氧化铝的3种主要的制备方法（固相法、气相法、液相法）进行说明,并着重论述了目前应用比较广泛的液相法和介孔纳米氧化铝的制备.最后,提出了一些在纳米氧化铝的制备研究中有待解决的问题.     

纳米四氧化三铁的化学制备方法研究进展

阐述了纳米四氧化三铁在磁性材料、多功能材料、催化材料以及医学领域的应用现状。对纳米四氧化三铁的制备方法如沉淀法、溶胶-凝胶法、微乳液法、水热与溶剂热法、热分解法、静电纺丝法等做了介绍。分析了各种纳米四氧化三铁材料的形态如纳米颗粒、纳米棒、纳米线、纳米膜、杂化、核壳结构纳米晶等的适用领域。总结了各种制备方法的研究进展,分析了其优缺点并结合作者课题组在纳米四氧化三铁制备方面的研究工作,对纳米四氧化三铁的今后的研究方向作了展望：制备特殊形貌的纳米四氧化三铁材料、减少纳米四氧化三铁的团聚和氧化、多种制备方法的结合以及如何实现大规模工业化生产。     

Effect of preparation parameters on the morphologically induced photocatalytic activities of hierarchical zinc oxide nanostructures

Hierarchical zinc oxide nanostructures were successfully synthesized by facile hydrothermal and sonochemical routes using citrate and PEG as structure directing agents. The effect of precursor concentration and preparation methods on the formation of typical morphology was systematically studied under hydrothermal and sonochemical conditions. Different concentrations of zinc acetate, sodium citrate and NaOH under hydrothermal and sonochemical methods generate different hierarchical structures such as flower-like, cabbage-like, and ellipsoidal ball-like morphologies, depending on the preparation conditions. The as-prepared ZnO samples were characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), transmission election microscopy (TEM), photoluminescence (PL) spectroscopy, Fourier transform infrared spectroscopy (FTIR) and particle size distribution (PSD) analysis. Catalytic activities of the as-prepared samples were studied by photodegradation of Methylene blue.     

Mechanical properties and morphologies of polypropylene with different sizes of calcium carbonate particles

Three polypropylene (PP) matrixes with different intrinsic toughness were used to study the morphologies and mechanical properties of PP filled with four sizes of calcium carbonate particles. PP1 was a homopolymer, PP2 was a propylene‐ethylene copolymer, and PP3 was a mixture of PP1 and PP2 (PP1:PP2 = 1:1, weight ratio). Calcium carbonate (CC25, CC4, CC1.8, and CC0.07) with an average particle size of 25, 4, 1.8, and 0.07 μm, respectively, was used. It was clear that the PP matrix and filler size had key effects on improvement of mechanical properties of PP matrix. For all three PP matrixes, the yield strength, the flexural strength and modulus of the composites filled with CC25, CC4, and CC1.8 could be regarded as the same. But the yield strength, the flexural strength and modulus of composites filled with CC0.07 were obviously lower than those of composites filled with other sizes of particles. Among four sizes of calcium carbonate particles, CC0.07 had the best toughening effect to improve the impact strength of PP matrix, and the toughening effect of CC0.07 was influenced by PP matrix. For all PP matrixes, only in the case of moderate matrix toughness (PP3 matrix), the composite could receive the highest extent of toughness increase (4.3 times that of matrix). With regard to all PP composites, the best combination of properties was PP2 nanocomposite filled with 20 wt% CC0.07. POLYM. COMPOS., 27:443–450, 2006. © 2006 Society of Plastics Engineers     

Biomimetic crystallization of calcium carbonate in the presence of water‐soluble zwitterionic block copolymer

Crystallization of calcium carbonate (CC) in aqueous solutions by gas‐liquid diffusion procedure was investigated systematically in the presence of poly(4‐sulfonic acid diphenylamine)‐block‐poly(ethylene glycol) (PSDA‐b‐PEG), wherein the PSDA block is a polymeric zwitterion. PSDA‐b‐PEG was synthesized with the reaction of tosylated PEG and amine‐functionalized PSDA and was characterized by nuclear magnetic resonance. The parameters such as, block copolymer concentration, crystallization time and initial pH were considered as indicators of block copolymer's capability in controlling the morphology of CC particles_. The particles were characterized by Fourier transform infrared, scanning electron microscopy, and X‐ray diffraction. The results suggest that PSDA‐b‐PEG is a suitable template to control the growth mechanism of CC to produce meso‐sized particles with different morphologies. POLYM. ENG. SCI., 59:96–102, 2019. © 2018 Society of Plastics Engineers     

Chemoenzymatic synthesis of Y‐shaped amphiphilic block copolymers and their micellization behavior

BACKGROUND: Y‐shaped block copolymers are a type of special star polymer that have received considerable attention due to their unique morphologies and phase behavior. This research is based on the preparation of novel Y‐shaped block copolymers using enzymatic ring‐opening polymerization (eROP) and atom‐transfer radical polymerization (ATRP), followed by an investigation of their micellization properties. RESULTS: Y‐shaped block copolymers consisting of polycaprolactone and poly(glycidyl methacrylate) were synthesized successfully by the combination of eROP and ATRP. NMR, gel permeation chromatography (GPC), Fourier transform infrared and atomic force microscopy analyses confirmed the compositions of the block copolymers. The dispersity obtained from GPC was less than 1.4, which indicated a control of the polymerization. The self‐assembly behavior of the Y‐shaped block copolymers was investigated in aqueous media. Aggregates of various morphologies (such as spherical micelles, lamellae, worm‐like micelles and large compound micelles) were observed. In addition, it was found that both the copolymer composition and concentration in tetrahydrofuran greatly influenced the morphologies of the aggregates. CONCLUSION: The results suggest that the Y‐shaped diblock copolymers can be synthesized by simple methods. They have various morphologies, including normal spherical micelles, lamellae, worm‐like micelles and large compound micelles. Copyright © 2009 Society of Chemical Industry     

多孔碳纳米球及其负载金属催化剂的研究进展

多孔碳纳米球由于可实现尺寸、形貌、孔结构以及表面基团等的可控合成制备,其负载/镶嵌的金属粒子又兼具高活性和高热稳定性等,在多相催化领域中受到越来越多的关注。本文追溯了多孔碳纳米球形貌调控的发展历程及其负载金属催化剂在催化反应领域中的应用。归纳了不同形貌的多孔碳纳米球及其制备方法和原理,详细对比了各个方法的优缺点;阐述了多孔碳纳米球负载金属催化剂的性能和碳球结构与形貌之间的构效关系;总结了目前碳球作为催化剂载体亟需解决的问题是碳球的多孔结构及其负载尺寸可控和空间匀称分布的金属粒子的可控合成,并展望了其发展方向是进一步研究和探索结构可调、经济可行的碳纳米球制备方法,真正实现工业化应用。     

无机铝盐辅助活性氧化铝水热合成拟薄水铝石

采用活性氧化铝为主要原料,直接水热合成或以铝盐水解产物为晶种通过水热法制备了形貌各异的拟薄水铝石,并利用扫描电镜、X射线衍射、物理吸附仪对其表观形貌、物相结构和孔结构进行了表征。结果表明,活性氧化铝具有很强的可塑性,可直接水热合成或在晶种存在下形成棱柱状、绒球状、片状等多种形貌的拟薄水铝石,为制备形貌可控的拟薄水铝石提供了一条新的制备方法。     

钒酸铋的形貌调整

钒酸铋由于其特殊的物理化学性质,在颜料、光催化、电极材料、离子导体材料等方面具有广泛的应用前景,其性能受钒酸铋的晶型、结构、表面状态和晶体形貌的因素的影响,很多研究人员探索了不同制备方法下对钒酸铋的形貌调整的方法,获得了诸如纳米线、纳米片、微米球等形貌的钒酸铋。对发明专利中涉及钒酸铋形貌调整的技术进行了总结梳理。