Pressure induced crystallization and in situ simultaneous SAXS/WAXS investigations on structure transitions

CrystEngComm ◽  
2020 ◽  
Vol 22 (28) ◽  
pp. 4748-4757 ◽  
Author(s):  
Shaoyong Huang ◽  
Hongfei Li ◽  
Shichun Jiang

A phase diagram of PLLA crystal structures as a function of crystallization temperature (Tc) and pressure (Pc).

Author(s):  
N. Rozhanski ◽  
A. Barg

Amorphous Ni-Nb alloys are of potential interest as diffusion barriers for high temperature metallization for VLSI. In the present work amorphous Ni-Nb films were sputter deposited on Si(100) and their interaction with a substrate was studied in the temperature range (200-700)°C. The crystallization of films was observed on the plan-view specimens heated in-situ in Philips-400ST microscope. Cross-sectional objects were prepared to study the structure of interfaces.The crystallization temperature of Ni5 0 Ni5 0 and Ni8 0 Nb2 0 films was found to be equal to 675°C and 525°C correspondingly. The crystallization of Ni5 0 Ni5 0 films is followed by the formation of Ni6Nb7 and Ni3Nb nucleus. Ni8 0Nb2 0 films crystallise with the formation of Ni and Ni3Nb crystals. No interaction of both films with Si substrate was observed on plan-view specimens up to 700°C, that is due to the barrier action of the native SiO2 layer.


2014 ◽  
Vol 1015 ◽  
pp. 381-384
Author(s):  
Li Liu ◽  
Li Hai Cai ◽  
Dan Liu ◽  
Jun Xu ◽  
Bao Hua Guo

The poly (butylene succinate) (PBS) and 3 wt% attapulgite (ATP) reinforced PBS/ATP nanocomposites with 1,6-hexanediol were fabricated using an in situ polymerization method. The crystallization behaviors indicated that ATP had effectively acted as nucleating agent, resulting in the enhancement on the crystallization temperature. The SEM results showed a superior interfacial linkage between ATP and PBS. Also, ATP could disperse as a single fiber and embed in the polymer matrix, which resulted in the improved mechanical properties.


2018 ◽  
Vol 6 (30) ◽  
pp. 14651-14662 ◽  
Author(s):  
Laura Vitoux ◽  
Marie Guignard ◽  
Jacques Darriet ◽  
Claude Delmas

Phase diagram in the NaxMoO2system (x≤ 0.5) determined using electrochemistry andin situX-ray powder diffraction.


2021 ◽  
pp. 102580
Author(s):  
Shengming Jiang ◽  
Ruihua Zhu ◽  
Ming Chen ◽  
Huanhuan He ◽  
Zhiwei Lin ◽  
...  

2014 ◽  
Vol 18 (01n02) ◽  
pp. 115-122 ◽  
Author(s):  
Srinivas Banala ◽  
Klaus Wurst ◽  
Bernhard Kräutler

We report here the preparation (in "one-pot") of a tetra-β″-sulfoleno-meso-aryl-porphyrin in about 80% yield by using an optimized modification of Lindsey's variant of the Adler–Longo approach. The Zn ( II )-, Cu ( II )- and Ni ( II )-complexes of the symmetrical porphyrin were prepared and characterized spectroscopically. Crystal structures of the fluorescent Zn ( II )- and of the non-fluorescent Ni ( II )-tetra-β″-sulfoleno-meso-aryl-porphyrinates showed the highly substituted porphyrin ligands to be nearly perfectly planar. The Zn ( II )-complex of this porphyrin has been used as a thermal precursor of a reactive diene, and — formally — of lateral and diagonal bis-dienes, of a tris-diene and of a tetra-diene, which all underwent [4 + 2]-cycloaddition reactions in situ with a range of dienophiles. Thus, the tetra-β″-sulfoleno-meso-aryl-porphyrin and its metal complexes represent reactive building blocks, "programmed" for the syntheses of symmetrical and highly functionalized porphyrins.


2018 ◽  
Vol 24 (9) ◽  
pp. 1421-1427 ◽  
Author(s):  
Feng Liu ◽  
Shaoai Xie ◽  
Yan Wang ◽  
Jianjun Yu ◽  
Qinghua Meng

PurposeThe titania (titanium dioxide) is one of the important functional additives in the photosensitive resin and encounters the problem of stabilization in the photosensitive resin for 3D printing. This study aims to achieve enhancement in stabilization by preparation of the polymerizable titania andin situlaser-induced crystallization during 3D printing.Design/methodology/approachA type of polymerizable titania (AAEM@TiO2) was designed and prepared from tetrabutyl titanate (TBT) and 2-(acetoacetoxy)ethyl methacrylate (AAEM) via the sol–gel process, which was characterized by Fourier-transform infrared (FTIR) spectra, ultraviolet–visible (UV-Vis) spectra, surface bonding efficiency (SBE) and settling height (H). AAEM acted on both bonding to the titania and polymerization with the monomer in resin for stabilization. The polymerizable titania could be converted to the pigmented titania by means of laser-induced crystallization. The photosensitive resin was then formulated on the basis of optimization and used in a stereolithography apparatus (SLA) for 3D printing.FindingsThe stabilization effect of AAEM on TiO2was achieved and the mechanism of competition in the light-consuming reactions during photocuring was proposed. The ratio of nAAEM/nTBTin AAEM@TiO2, the concentration of AAEM@TiO2and photoinitiator (PI) used in the photosensitive resin were optimized. The anatase crystal form was indicated by X-ray diffraction (XRD) and clustering of nanocrystals was revealed by scanning electron microscopy (SEM) after SLA 3D printing.Originality/valueThis investigation provides a novel method of pigmentation by preparation of the polymerizable titania andin situlaser-induced crystallization for SLA 3D printing.


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