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1.
采用溶剂热法,用过硫酸钾引发苯乙烯均聚,制备出分散性好、粒径约30nm的无皂聚苯乙烯肢乳纳米粒子。讨论了引发剂的用量、助溶剂丙酮的含量、反应温度对粒子尺寸及其粒径分布的影响。实验结果表明:在一定范围内,温度改变,粒径变化较快;引发剂、丙酮和单体用量改变时,粒径变化较缓慢。  相似文献   

2.
以过硫酸钾作为引发剂进行了甲基丙烯酸丁酯的微波无皂化乳液聚合,讨论了单体浓度和引发剂用量对单体转化率,粒子粒径及其分布的影响,并与常规乳液聚合进行了比较。结果表明,通过微波无皂乳液聚合,乳胶粒子的粒径分布没有明显变化,但是聚合速率大为增加。  相似文献   

3.
以过硫酸铵为引发剂,固定反应单体物质的量之比,采用一步无皂乳液聚合法,制备粒径不同的聚(苯乙烯-N- 异丙基丙烯酰胺)纳米粒子,研究了反应单体用量对纳米粒子粒径的影响;然后利用简单的垂直沉积法,在载玻片上自组装光子晶体薄膜。结果表明:制备的纳米粒子具有较高的单分散性并呈明显的核 壳结构,其粒径与反应单体用量呈线性关系;薄膜中纳米粒子呈面心立方紧密堆积,薄膜厚度约8 μm;薄膜光子禁带的实验测量值与理论计算值基本一致,且禁带与纳米粒子粒径呈线性关系;当反应单体的总物质的量分别为20,25,30,35 mmol时,自组装成的光子晶体薄膜的颜色分别呈蓝紫、蓝绿、黄绿和橘红色。  相似文献   

4.
以丙烯酸丁酯、甲基丙烯酸以及丙烯腈为主要原料合成了新型附聚剂。探讨了单体加料方式、附聚剂粒径、附聚剂的用量、滴加时间和pH对丁苯胶乳粒径大小及其分布和胶乳稳定性的影响,且对附聚后丁苯胶乳粒径分布及其形态进行了测试。  相似文献   

5.
采用疏水引发剂引发的半连续无皂乳液聚合法,合成了Z均流体力学直径约70 nm的聚甲基丙烯酸甲酯(PMMA)纳米乳胶。以PMMA纳米乳胶为种子,采用疏水引发剂引发的种子乳液聚合法,制备了PMMA 聚丙烯腈(PAN)核壳结构复合乳胶。采用动态光散射、傅里叶红外光谱、扫描电镜和透射电镜表征了各种乳胶粒的组成、尺寸、结构和微观形态。研究了反应温度、单体用量和表面活性剂用量对PMMA-PAN复合乳胶粒的结构和形态的影响。结果表明:PMMA PAN复合乳胶粒为核壳结构,其壳层厚度可通过改变单体用量进行调整。  相似文献   

6.
综述了目前制备核壳型聚丙烯酸酯乳胶粒子的常用方法,如种子乳液聚合法、无皂乳液聚合法、反相乳液聚合法、细乳液聚合法以及种子分散聚合法;分析了聚合工艺、单体种类、温度、乳化剂和引发剂种类及用量等因素对聚丙烯酸酯核壳乳液合成及性能的影响;并对聚丙烯酸酯核壳乳液的研究现状进行了归纳;最后,展望了聚丙烯酸酯核壳乳液的发展方向。  相似文献   

7.
微米级聚苯乙烯微球广泛用于临床分析、生物医学、胶体研究等领城,亦可作为电子显微镜、光散射、沉降法等测定微小物体绝对长度的基准物、色谱柱填料等。用分散聚合法可以制得微米级单分散聚苯乙烯微球。本文通过对分散聚合条件和配方的研究,以水和醇为分散介质,分子量4000的聚乙二醇为稳定剂,过氧化苯甲酰为引发剂,合成了粒径为3至4μm的单分散聚苯乙烯微球。在分散聚合体系中,随着有机溶剂、单体、引发剂等用量的增加,胶乳粒径增大,粒径分布变宽。随着稳定剂、表面张力调节剂等用量的增加,胶乳粒径减小,粒径分布变窄。有机溶剂种类改变以及聚合反应温度变化,胶乳粒径也发生变化。  相似文献   

8.
以苯乙烯为单体,采用分散聚合法制备了单分散性的聚苯乙烯(PS)微球,然后以PS微球作为种子、丙烯酸(AA)进行无皂种子乳液聚合制备了PS/PAA微球。考察了单体、引发剂、分散剂用量,反应介质极性和交链剂等因素对微球粒径大小及其分布的影响,探讨了分散聚合的反应机理。结果表明,通过改变反应工艺条件,能够制备粒径为1.0~3.0μm、单分散性很好的PS微球;通过无皂种子乳液聚合得到的核壳结构的PS/PAA微球粒径为2.50μm,多分散系数(PI)为0.0325,酸值为10.27mgNaOH/g,其表面带有羧基的特性能进一步扩大应用范围。  相似文献   

9.
以苯乙烯(St)与丙烯酸丁酯(BA)为非离子单体、十六烷基三甲基氯化铵(CTAC)为乳化剂、偶氮二异丁基脒盐酸盐(AIBA)和偶氮二异丁咪唑啉盐酸盐(AIBI)为引发剂,进行间歇式阳离子乳液聚合。探讨了引发剂的用量和分子结构对瞬时转化率、乳胶粒粒径、粒径分布和粒子形态等的影响。结果表明:引发剂用量越大,单体转化率越高,乳胶粒粒径越小,粒径分布越大;使用AIBI作引发剂时,单体转化率较高,乳胶粒粒径较小。  相似文献   

10.
以过硫酸钾(KPS)为引发剂、十二烷基硫酸钠(SDS)为乳化剂,利用正相乳液聚合制备(甲基丙烯酸甲酯-co-丙烯酸)共聚物(P(MMA-co-AA))乳液.通过测定聚合转化率和观察聚合过程稳定性,探讨了AA与MMA不同质量比时制备稳定的共聚物乳液的工艺条件;通过黏度法测定了乳液在不同pH时的相对黏度η,利用粒度分析仪分析了乳胶粒子在不同pH时的平均粒径和粒径分布.结果表明:AA含量较高时,控制聚合时间是得到稳定聚合物乳液的关键,当m(AA)/m(MMA)=12.5/100,65 ℃下反应120 min时,所制得的乳液稳定性最好.随着pH增大,乳液黏度先增大后降低;随着m(AA)/m(MMA)增加,制得的乳液pH敏感性增大;随着乳液从酸性(pH=5.17)变到碱性(pH=8.61),聚合物乳胶粒子平均粒径减小,粒径分布变窄.  相似文献   

11.
CASE HISTORY A female patient, 46 years old, head of the foreign affairs department of a certain university in Beijing, paid her first visit on October 9, 2006, with the chief complaint of vomiting for one month. She got vomiting after meals in early September. Before that, she had discomfortable sensation in the stomach due to angry with others, but she didn't pay much attention. Later, it developed into vomiting after eating. After the vomiting, the discomfort would be relieved, but with slight hypodynamia. She was once diagnosed as having 'neurogenic vomiting'. Having taken some western and Chinese drugs, the above symptoms were a little bit improved, but she would have nausea upon eating and with regurgitation. Because of the fear for vomiting, she did not dare to have food intake, with body weight reduction of 6 kilos in one month.  相似文献   

12.
Radiotherapy and chemotherapy are the important modern medical therapies for malignant tumors,yet they can also bring about serious local and systemic toxic side reactions so to decrease the patient;'s life quality,manifested by a series of consumptive symptoms.Having engaged in the combined work of Chinese and western medicine for nearly 50 years,the research fellow Qiu Baoguo in Henan Provincial Academy of TCM has developed his unique views on the TCM study of consumptive syndromes.The author of this essay had once the fortune tO follow Dr.Qiu in clinic,and specially would like to introduce in the following Dr.Qiu's experience in treating consumptive syndromes after radio-chemotherapies for patients with malignant tumor.  相似文献   

13.
OBJECTIVE: To observe therapeutic effects of the comprehensive therapy of acupuncture-moxibustion and Chinese Tuina for treatment of insomnia due to deficiency of both the heart and spleen. METHODS: 92 cases were divided randomly into the treatment group (treated by acupuncture-moxibustion and Chinese Tuina) and the control group (treated by acupuncture-moxibustion). RESULTS: The therapeutic effect of the treatment group was obviously superior to that of the control group (the CHI2 test showed P < 0.01). CONCLUSIONS: The comprehensive therapy of acupuncture-moxibustion and Chinese Tuina can give marked therapeutic effects for treatment of insomnia due to deficiency of both the heart and spleen.  相似文献   

14.
15.
Objective: To investigate if there are the CK-19, PDX-1, Nestin, Ngn3 positive cells in the donor islets of different purity in rats. Methods: Thirty male adult SD rats were randomly divided into 3 groups. Islets were isolated using digestion by ductal injection of collagenase. Group Ⅰ (n=10): Separating cell preparations were not purified, Group Ⅱ(n=10): Islet sediment was purified with 25% Ficoll400 ,Group Ⅲ (n=10): Islet sediment was purified with 25% and 11% Ficoll-400. The levels of protein of CK-19, PDX-1, Nestin and Ngn3 were detected by immunohistochemistry and the mRNA of CK-19, PDX-1, Nestin, Ngn3 was amplified by RT-PCR. Results: After two different purification methods applied, three islet preparations of different purities were obtained. The difference of islet purity was significant among various groups (P<0.05). Compared with group Ⅱ and group Ⅲ,the protein and mRNA of CK-19, PDX-1, Nestin,Ngn3 were both higher in group Ⅰ; group Ⅲ was poorly expressed. Conclusions: The three different islet purity donor islet have different CK-19, PDX-1, Nestin, Ngn3 positive cells within them, indicating that there are some islet stem cells in the purified donor islet.  相似文献   

16.
Objective:To investigate the optimum screening conditions of associated proteins in human psoriasis vulgaris by serum proteomics technique, and to screen the different expression proteins related with psoriasis vulgaris. Methods:Serum samples of peripheral blood were collected from newly diagnosed psoriasis vulgaris patients in the clinic, and 20 matched healthy persons. Serum albumin IgG was removed by filtering with ProteoExtract Albumin/IgG. After comparative proteomics analysis the different protein spots were identified using 2-DE and MS. Results :Electrophoresis figures with high resolution and reproducibility were obtained. Three different expression proteins were found only in the serum from psoriasis vulgaris patients, while nine other different proteins expressing from healthy volunteers. Conclusion:The protein expression was different in the serum between the psoriasis vulgaris patients and healthy volunteers. It was hoped that we could find the biomarkers related to psoriasis vulgaris by using proteomics.  相似文献   

17.
PYTOBEZOARS are common bezoars in gastrontestinal tract, commonly seen in stomach and mall intestine,1but huge disopyrobezoars are  相似文献   

18.
CASE HISTORY A male,a retired officer of 61 years old,paid his first visit on May 12,2006.The patient stated that 2 weeks before he suddenly got paroxysmal precordial choking pain,with irregular attacks.Each attack would last several seconds to several minutes.The attack was accompanied with heavy oppressed sensation in the precordial region,palpitation,lassitude,and in severe cases,sweating,which was once diagnosed by a hospital as'coronary heart disease'.Recalling the case history,the patient said that several days before he got angry with others because of some affairs in work,and he was not so used to the life pattern since he had just retired from his busy working post.At usual times,he was quick tempered and peevish.In recent days,he had poor appetite,and loose stool.  相似文献   

19.
The English edition of Chinese Journal of Integrative Medicine is edited and published by the Chinese Journal of Integrated Traditional and Western Medicine Press.Original scientific papers of advanced clinical and experimental medicine in the field of complementary/alternative medicine or integrative medicine are expected.  相似文献   

20.
<正>As culture is the soul of a nation,the three books,"History of Chinese Philosophy,""History of Chinese Culture"and"History of Chinese Science and Technology"have demonstrated the superiority of our great Chinese culture,and its significant impact in the field of international culture.Both core value and practical value of the Chinese culture are very clear,reflected in the views of universe,nature,life,health,disease,and therapy and related considerations,concepts,and technical methods.  相似文献   

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