Meniscus-Assisted Solution Printing Enables Cocrystallization in Poly(3-alkylthiophene)-based Blends for Field-Effect Transistors

The formation of cocrystallization in two various conjugated components may endow the newly formed conjugated cocrystals with multiple functionalities and improved charge transport properties.However,compared to conjugated small molecules,this strategy is rather limitedly realized in conjugated polymers.Herein,a simple meniscus-assisted solution printing(MASP)strategy is utilized to achieve the cocrystallization in the blends of two conjugated polymers,i.e.,poly(3-hexylthiophene)(P3HT)and poly(3-octylthiophene)(P3OT),and the cocrystalline structures are correlated closely to their charge mobilities.The P3HT/P3OT blends phase separate and crystallize individually in their drop-cast thin films.When subjecting the P3HT/P3OT blended solution to MASP,the confined solvent evaporation between two nearly parallel plates triggers them to cocrystallize progressively when accelerating the moving lower plate.The cocrystallization kinetics and the changes in P3HT/P3OT molecular structures are elucidated.Finally,these different crystalline structures of P3HT/P3OT blends are applied in organic fieldeffect transistors,imparting the cocrystallization-enhanced charge transport than respective P3HT and P3OT crystal domains.Such MASP method can be extended to craft cocrystals of other conjugated polymer blends for their diverse optoelectronic applications.

不同温度下CL-20/DNDAP共晶形貌的分子动力学模拟

将六硝基六氮杂异伍兹烷(CL-20)与其他含能材料形成共晶,并使共晶形貌接近球形可以降低其感度。采用附着能(AE)模型和分子动力学(MD)方法预测了不同温度下乙酸甲酯溶剂中的CL-20和2,4-二硝基-2,4-二氮杂戊烷(DNDAP)共晶形貌。同时,计算了溶剂和晶体表面之间的相互作用能,求得晶体表面的附着能,对不同温度下的晶体形貌进行了模拟。结果表明,真空下CL-20/DNDAP共晶体有5个主要生长晶面,(100)面占据相对较大的面积,占比为37.44%,对晶体形貌产生重要影响;CL-20/DNDAP共晶的晶面附着能随着温度的升高而降低,温度升高导致长径比增大,温度为280和360K时的长径比分别为1.80和3.93;较低的温度有利于获得近似球状形貌;理论预测的形貌为斜棱柱且与实验结果吻合良好。

A review on cocrystal of active ingredients in traditional Chinese medicine

In the development of new drugs products,especially the development of traditional Chinese medicine active ingredients,solubility and oral bioavailability are the main factors which are restricting the development of new drugs,whereas the physicochemical properties of active ingredients are the key element to affecting these factors.Pharmaceutical cocrystal provides an excellent opportunity to develop new drugs with excellent physical and chemical properties such as melting point,solubility,stability and bioavailability while retaining the pharmacological properties of individuals active pharmaceutical ingredients among pharmaceutical cocrystal compounds.Traditional Chinese herbal medicine has the characteristics of multiple pathways and multiple targets,mainly because it contains many active ingredients,like cocrystals thereof with many components.The active ingredients extracted from traditional Chinese herbal medicine have a wide range of pharmacological activities,but most of the active ingredients affect the development of traditional Chinese medicine active ingredients due to their physical and chemical properties such as solubility.Traditional Chinese medicine pharmaceutical cocrystals can not only improve the physical and chemical properties of drugs without changing the internal structure of drugs,so as to provide a new scheme for the development of traditional Chinese medicine active ingredients.This paper reviews the research progress of active ingredients of traditional Chinese medicine pharmaceutical cocrystal.The preparation methods of cocrystals are summarized and the advantages of cocrystals are illustrated with examples.

Studies on ammonium dinitramide and 3,4-diaminofurazan cocrystal for tuning the hygroscopicity

Ammonium dinitramide(ADN)is a promising oxidizer with high energy characteristic,which is a relatively new environmentally friendly oxidizer without halogens and carbon elements.However,ADN has high hygroscopicity when exposed to high humidity air,restricting its applications on the solid propellants.In this paper,a novel energetic cocrystal composed of ammonium dinitramide and 3,4-diaminofurazan(DAF)was proposed and successfully synthesized by antisolvent crystallization method,and the properties of the cocrystal were systematically investigated by analytical characterization and theoretical simulation calculations.The formation of the cocrystal was confirmed by powder X-ray diffraction,differential scanning calorimetry,scanning electron microscopy,infrared spectroscopy and Raman spectroscopy,indicating that the synthesized product was a cocrystal.Through theoretical studies,the ADN/DAF cocrystal structure was predicted,and the powder X-ray diffraction,morphology,water sorption capacity of ADN/DAF cocrystal were calculated,which was consistent with experimental phenomena.The results showed that newly prepared cocrystal of ADN/DAF had lower hygroscopicity compared to pure ADN,and the water sorption capacity was reduced from 15.35%to 7.90%.This may be due to the formation of N-H…O medium-strength hydrogen bonds between the ammonium ion of ADN and the O atom of DAF in the cocrystal,which prevents the binding of water molecules in the air and ammonium ions and reduces the probability of ADN binding to water molecules,leading to the reduction of cocrystal hygroscopicity.The newly prepared energetic cocrystal can provide theoretical and technical guidance for the study of the anti-hygroscopicity of ADN and advance the practical application of ADN.

Optimized solubility and bioavailability of genistein based on cocrystal engineering

With various potential health-promoting bioactivities,genistein has great prospects in treatment of a series of complex diseases and metabolic syndromes such as cancer,diabetes,cardiovascular diseases,menopausal symptoms and so on.However,poor solubility and unsatisfactory bioavailability seriously limits its clinical application and market development.To optimize the solubility and bioavailability of genistein,the cocrystal of genistein and piperazine was prepared by grinding assisted with solvent based on the concept of cocrystal engineering.Using a series of analytical techniques including single-crystal X-ray diffraction,powder X-ray diffraction,Fourier transform infrared spectroscopy,differential scanning calorimetry and thermogravimetric analysis,the cocrystal was characterized and confirmed.Then,structure analysis on the basis of theoretical calculation and a series of evaluation on the stability,dissolution and bioavailability were carried out.The results indicated that the cocrystal of genistein and piperazine improved the solubility and bioavailability of genistein.Compared with the previous studies on the cocrystal of genistein,this is a systematic and comprehensive investigation from the aspects of preparation,characterization,structural analysis,stability,solubility and bioavailability evaluation.As a simple,efficient and green approach,cocrystal engineering can pave a new path to optimize the pharmaceutical properties of natural products for successful drug formulation and delivery.

ZSM-5/MOR混晶分子筛的研究

分别以水玻璃、硫酸铝为硅源和铝源,加入NaZSM-5合成ZSM-5／MOR混晶分子筛。用XRD,SEM,BET,NH3-TPD等方法对混晶分子筛进行表征;在450℃下考察其对裂化和甲苯烷基化的催化性能,并与ZSM-5和丝光沸石的机械混合物进行对比。结果表明,混晶分子筛中存在的丝光沸石、ZSM-5不是呈纯粹的物理混合状态,混晶分子筛的酸性和酸量与机械混合物有所不同,水蒸气老化混晶分子筛对正十四烷的裂化活性较机械混合物强;而老化前机械混合物的甲苯烷基化活性较混晶分子筛强,但两者对3种二甲苯的选择性无差异。

磷石膏中杂质的形态及水溶性磷对水泥物理性能的影响

在对磷石膏中杂质的类型、存在形式及磷石膏的溶解性质检测分析的基础上 ,研究了磷石膏中水溶性磷含量以及磷石膏直接替代天然石膏用作水泥缓凝剂对水泥质量的影响。结果表明 ,磷石膏中的主要杂质为 :以H3PO4、H2 PO-4 或HPO2 -4 形式存在的可溶性P2 O5、与金属共生磷酸盐复合物和共晶形式存在的不溶性P2 O5及石英。磷石膏中的水溶性磷含量 <1%时 ,对水泥物理性能的影响不大 ,磷石膏中的水溶性磷含量 >1%时 ,水泥的凝结时间明显延长 。

偶联剂对膨胀石墨复合阻燃聚丙烯的影响

探讨了无机膨胀型阻燃剂膨胀石墨(EG)与协同阻燃剂聚磷酸铵(APP)复合阻燃聚丙烯(PP)材料中EG与APP的最佳配比及不同种类偶联剂对复合阻燃PP材料力学性能的影响。研究表明,当EG/APP为2∶1,两组分具有较好的协同作用,材料的综合性能较好;通过测定材料的拉伸强度和冲击强度,确定了最佳偶联剂为KH 570,其最佳用量为阻燃剂用量的1.5%(质量分数)。以此为基础,考察了阻燃剂不同用量对材料的拉伸强度、冲击强度、氧指数、表面电阻率、烟密度等级等性能的影响,比较了阻燃剂不同用量时材料的综合性能。

HMX降感技术研究进展

以HMX降感为主线,分别从改善HMX晶体品质、表面包覆和共结晶三方面综述了近年来国内外的研究进展。对各方法的特点、降感机理及效果进行了介绍,指出从微观结构角度对HMX进行改性,即选择钝感含能化合物与HMX共结晶,是降低HMX感度最本质有效的方法。以现有研究为基础,总结并提出了今后研究工作中应注意的一些问题和研究重点。

PA6/PP共混物的研究进展

对PA6 /PP共混物的研究进展进行了综述。重点介绍了所用增容剂的种类及增容机理、共混体系结构和性能的研究状况 ,并对PA6 /PP共混物今后的研究方向提出了建议。

聚丙烯纤维在混凝土高温后抗压抗折中不同表现的分析

高性能混凝土的抗火性能比普通混凝土差,在混凝土中加入聚丙烯微纤维可作为一种有效的混凝土温差补偿抗裂手段。通过大量高温和力学试验,研究了聚丙烯纤维在不同温度下对矿渣和硅灰高性能混凝土的抗压、抗折的影响并发现对不同的力学指标纤维的作用相差很大。笔者尝试从高温中和高温后PP纤维在混凝土中的力学行为着手分析其在混凝土高温后不同力学性能的贡献。

聚合物共结晶行为的研究现状

对发生于结晶聚合物 /结晶聚合物共混体系中的共结晶行为近期的研究状况作了综述。对共结晶的含义 ,影响共结晶的因素 ,形成共晶的条件和原因 。

高密度聚乙烯／低密度聚乙烯／乙烯－醋酸乙烯共聚物共混体系的结晶行为

通过ＤＳＣ和ＷＡＸＤ研究了高密度聚乙烯／低密度聚乙烯／乙烯－醋酸乙烯共聚物（ＨＤＰＥ／ＬＤＰＥ／ＥＶＡ）三元共混体系的热行为和结晶性能。发现当ＨＤＰＥ含量小于４０％时，ＥＶＡ对ＬＤＰＥ起稀释剂作用，促进ＨＤＰＥ、ＬＤＰＥ的晶相分离，使ＨＤＰＥ、ＬＤＰＥ单独结晶．当ＨＤＰＥ含量高于４０％时，ＬＤＰＥ片晶进入ＨＤＰＥ晶相。形成与ＬＤＰＥ在片晶水平上的共晶。

脱蜡助剂对蜡结晶作用机理初步研究

为研究脱蜡助剂的作用机理,选取6种脱蜡助剂和荆门(J M)轻脱加氢处理糠精油(简称荆门油)和茂名(MM)轻脱糠精油(简称茂名油)2种原料油,两两匹配进行脱蜡试验,筛选出对这2种原料油助滤效果最好的脱蜡助剂A剂和C3剂。采用偏光显微镜、XRD及DSC对其作用机理进行了初步研究。结果表明,荆门轻脱加氢处理蜡(简称荆门蜡)与A剂的作用机理可能是共晶-吸附作用;A剂吸附在蜡晶侧面,其聚乙烯链段进入蜡晶晶格与蜡共晶,而醋酸乙烯酯链段则阻止蜡分子在侧面结晶,抑制其沿x轴和y轴方向的生长,促进沿z轴方向的生长,改变蜡的生长习性,增大蜡晶粒度,提高滤速。茂名轻脱蜡(简称茂名蜡)与C3剂的作用机理可能是共晶机理;其烷基侧链与蜡发生共晶作用,通过"搭桥效应"将蜡晶连接成为大的蜡晶聚集体,提高滤速。

聚丙烯/三元乙丙橡胶共混材料表面紫外光接枝聚丙烯酰胺的研究

采用紫外光接枝方法,在聚丙烯(PP)/三元乙丙橡胶(EPDM)共混板材表面接枝聚丙烯酰胺(PAAM)。用衰减全反射傅里叶变换红外光谱、X射线光电子能谱、接触角测试仪和扫描电子显微镜对接枝改性PP板表面进行了研究,并讨论EPDM含量、辐照时间、单体及引发剂用量对接枝量和接触角的影响。结果表明,在共混板材表面成功接枝了PAAM,当EPDM的含量为共混板材的20%时,改性PP板表面接枝量达到0.75mg/cm2;接触角从102.5°下降到72.5°;表面自由能从16.6mN/m增大到48.7mN/m。

共晶和共混对CL-20/DNB感度和热解机理影响的MD模拟

为了从分子水平进一步揭示共晶和共混对六硝基六氮杂异伍兹烷(CL-20)/1,3-二硝基苯(DNB)含能材料的感度、力学性能和热解机理的影响,采用分子动力学(MD)模拟方法在COMPASS力场条件下对CL-20、DNB、两者的共混物及共晶的感度、结合能和力学性能进行了模拟计算。在Reax FF/lg力场条件下对其热解机理进行了研究。结果表明,共晶和共混均会降低体系的感度,但共晶效果更加明显;与共混物结构相比,共晶结构更加稳定,共晶和共混均可以改变复合体系的力学性能,降低体系的刚度,增加体系的柔性和安全性,但共混会使体系的力学性能劣化。共晶分子间强的作用会促进体系中各组分的热解反应,NO_2、N_2、NO、H_2O、HONO、HON以及CO_2等是共晶和共混体系的主要热解产物。与共混相比,共晶是一种更加有效的含能材料改性方法,可为含能材料的配方设计提供理论指导。

HDPE/LDPE共混体系的晶性研究

用DSC和WAXD方法考察了高密度聚乙烯和低密度聚乙烯共混体系(HDPE/LDPE)的结晶性能。结果表明,在共混物中HDPE含量大于50%时,共混物只出现HDPE的熔融峰,且熔融温度随HDPE含量减小而降低;LDPE含量大于50%时,DSC图上只出现熔点介于HDPE和LDPE之间的新熔融峰。DSC和WAXD法所测结晶度均偏离共混物的线性加和值,而晶胞参数则随共混物组成变化出现最小值,表明HDPE和LDPE可以形成共晶相容体系。Raman光谱测得介晶相αb值的膨胀,支持这一观点。

蔗糖共结晶产品的研制

阐述了共结晶工艺过程原理，提出了共结晶产品研制的工艺流程及对不同添加配料确定主要工艺参数的方法。结果表明，共结晶技术夹带食品、医药配料是可行的，共结晶产品含有原有投料的所有固形物。

差示扫描量热法研究HDPE与LLDPE共混

对两种不同类型的聚乙烯采用溶液共混的方法进行共混,采用差示扫描量热法(DSC)研究了其混容性,并对影响共结晶的因素进行了的探讨。

蔗糖—薄荷醇共结晶微胶囊的研究

采用共结晶技术将薄荷醇嵌入蔗糖，得到一种稳定、干燥的蔗糖—薄荷醇共结晶产物。