Rubber compounds based on styrene-butadiene rubber/ethylene propylene diene monomer blends of different compositions （60/40, 70/30, 80/20, 90/10, 100/0） reinforced with 1 wt%, 3 wt%, 5 wt% and 7 wt% organoclay （Clo...Rubber compounds based on styrene-butadiene rubber/ethylene propylene diene monomer blends of different compositions （60/40, 70/30, 80/20, 90/10, 100/0） reinforced with 1 wt%, 3 wt%, 5 wt% and 7 wt% organoclay （Cloisite 20A） were prepared on a two roll mill via a vulcanization process and characterized by several techniques. Results of X-ray diffraction showed expansion of the inter-gallery distance, and transmission electron microscopy （TEM） micrographs confirmed that the prepared nanocomposite samples have intercalated and partially exfoliated structures. Cure characteristics showed that, organoclay not only accelerates the vulcanization reaction, but also gives rise to a marked increase of the torque, indicating crosslink density of the prepared compounds increases at the presence of organoclay. Mechanical properties of samples received markedly increase by clay loading due to the good interaction established between nanoclay particles and polymer matrix as it was evidenced by SEM photomicrographs. At the same time, rheological properties showed that addition of nanoclay could improve storage modulus as well as complex viscosity of SBR/EPDM samples. The results of ozone test revealed that the ozone resistance of samples significantly increases as nanoclay or EPDM content increases.展开更多
1 INTRODUCTIONIn recent years,colloidal dispersion gel(CDG)have been attracting more and more in thefield of enhanced oil recovery on account of the cost-effectiveness and high efficiency ofblocking formation.Compared...1 INTRODUCTIONIn recent years,colloidal dispersion gel(CDG)have been attracting more and more in thefield of enhanced oil recovery on account of the cost-effectiveness and high efficiency ofblocking formation.Compared with bulk gel(BG),CDG exhibits lower polymer concentra-tion,undefined shape and selective blocking formation characteristics.The characteris-tics of CDG and BG are related to structure.In the bulk gel a continuous network of polymermolecules is formed predominant through intermolecular cross-linkages.The展开更多
The purpose of this study is to examine optical spatial frequency spectroscopy analysis(SFSA)combined with visible resonance Raman(VRR)spectroscopic method,for thefirst time,to discriminate human brain metastases of l...The purpose of this study is to examine optical spatial frequency spectroscopy analysis(SFSA)combined with visible resonance Raman(VRR)spectroscopic method,for thefirst time,to discriminate human brain metastases of lung cancers adenocarcinoma(ADC)and squamous cell carcinoma(SCC)from normal tissues.A total of 31 label-free micrographic images of three type of brain tissues were obtained using a confocal micro-Raman spectroscopic system.VRR spectra of the corresponding samples were synchronously collected using excitation wavelength of 532 nm from the same sites of the tissues.Using SFSA method,the difference in the randomness of spatial frequency structures in the micrograph images was analyzed using Gaussian functionfitting.The standard deviations,calculated from the spatial frequencies of the micrograph images were then analyzed using support vector machine(SVM)classifier.The key VRR biomolecularfingerprints of carotenoids,tryptophan,amide II,lipids and proteins(methylene/methyl groups)were also analyzed using SVM classifier.All three types of brain tissues were identified with high accuracy in the two approaches with high correlation.The results show that SFSA–VRR can potentially be a dual-modal method to provide new criteria for identifying the three types of human brain tissues,which are on-site,real-time and label-free and may improve the accuracy of brain biopsy.展开更多
文摘Rubber compounds based on styrene-butadiene rubber/ethylene propylene diene monomer blends of different compositions （60/40, 70/30, 80/20, 90/10, 100/0） reinforced with 1 wt%, 3 wt%, 5 wt% and 7 wt% organoclay （Cloisite 20A） were prepared on a two roll mill via a vulcanization process and characterized by several techniques. Results of X-ray diffraction showed expansion of the inter-gallery distance, and transmission electron microscopy （TEM） micrographs confirmed that the prepared nanocomposite samples have intercalated and partially exfoliated structures. Cure characteristics showed that, organoclay not only accelerates the vulcanization reaction, but also gives rise to a marked increase of the torque, indicating crosslink density of the prepared compounds increases at the presence of organoclay. Mechanical properties of samples received markedly increase by clay loading due to the good interaction established between nanoclay particles and polymer matrix as it was evidenced by SEM photomicrographs. At the same time, rheological properties showed that addition of nanoclay could improve storage modulus as well as complex viscosity of SBR/EPDM samples. The results of ozone test revealed that the ozone resistance of samples significantly increases as nanoclay or EPDM content increases.
文摘1 INTRODUCTIONIn recent years,colloidal dispersion gel(CDG)have been attracting more and more in thefield of enhanced oil recovery on account of the cost-effectiveness and high efficiency ofblocking formation.Compared with bulk gel(BG),CDG exhibits lower polymer concentra-tion,undefined shape and selective blocking formation characteristics.The characteris-tics of CDG and BG are related to structure.In the bulk gel a continuous network of polymermolecules is formed predominant through intermolecular cross-linkages.The
基金This research is supported by The Air Force Medical Center,China and in part of The Institute for Ultrafast Spectroscopy and Lasers(IUSL),the City College of the City University of New York.The authors would like to thank Mr.C.Y.Zhang,Mr.M.Z.Fan and Dr.X.H.Ni for their assistance in the experiments and suggestions concerning this paper.
文摘The purpose of this study is to examine optical spatial frequency spectroscopy analysis(SFSA)combined with visible resonance Raman(VRR)spectroscopic method,for thefirst time,to discriminate human brain metastases of lung cancers adenocarcinoma(ADC)and squamous cell carcinoma(SCC)from normal tissues.A total of 31 label-free micrographic images of three type of brain tissues were obtained using a confocal micro-Raman spectroscopic system.VRR spectra of the corresponding samples were synchronously collected using excitation wavelength of 532 nm from the same sites of the tissues.Using SFSA method,the difference in the randomness of spatial frequency structures in the micrograph images was analyzed using Gaussian functionfitting.The standard deviations,calculated from the spatial frequencies of the micrograph images were then analyzed using support vector machine(SVM)classifier.The key VRR biomolecularfingerprints of carotenoids,tryptophan,amide II,lipids and proteins(methylene/methyl groups)were also analyzed using SVM classifier.All three types of brain tissues were identified with high accuracy in the two approaches with high correlation.The results show that SFSA–VRR can potentially be a dual-modal method to provide new criteria for identifying the three types of human brain tissues,which are on-site,real-time and label-free and may improve the accuracy of brain biopsy.
基金Projects(52022053,52009073)supported by the National Natural Science Foundation of ChinaProject(ZR201910270116)supported by the Natural Science Foundation of Shandong Province,China。
