34 results about "Polar crystal" patented technology

The present invention discloses a high beta crystal form content polyvinylidene fluoride composite material and a preparation method thereof. The composite material comprises ionic liquid modified carbon nanotubes and an organic material polyvinylidene fluoride, wherein a mass ratio of the polyvinylidene fluoride substrate to the modified carbon nanotubes is 100:0-12, and a mass ratio of the ionic liquid to the carbon nanotubes is 0-10:1. The preparation method comprises: carrying out coating modification on carbon nanotubes by using an ionic liquid, carrying out melt blending on the modified carbon nanotubes and polyvinylidene fluoride, and carrying out direct melt molding cooling to obtain the finished product. According to the present invention, polar crystal form content of PVDF in the prepared composite material can be 100%, the preparation process has characteristics of simpleness, energy source saving, and green environment protection, and the polyvinylidene fluoride composite material is expected to be provided for preparing various devices in fields such as piezoelectric materials, thermoelectric materials, dielectric materials and the like.

A method and device for generating terahertz radiation comprising a polar crystal material layer operative to emit terahertz radiation; the polar crystal material layer comprising a plurality of stacking faults; the stacking faults lying substantially perpendicular to the polar axis and forming boundaries at which the internal electric polarization terminates leading to charges accumulating at the boundaries, and creation of internal electric fields oriented along the polar axis; a pulsed radiation source for creating photogenerated carriers in the polar crystal material; whereby the photogenerated carriers accelerate in the internal electric fields associated with the termination of the internal electric polarization by the stacking faults to thereby generate terahertz radiation.

The invention discloses polar crystal-form polyvinylidene fluoride and a preparation method of a composite thereof. The preparation method includes: adding CTAB (cetyltrimethyl ammonium bromide) serving as nucleating agents so as to obtain high-content polar crystals, using 40%-99.9% of PVDF (polyvinylidene fluoride), 0.1%-10% of the cetyltrimethyl ammonium bromide and 0%-50% of packing as raw materials, uniformly mixing the raw materials by solution mixing or melting mixing, and forming so that the target composite is obtained. Highly-polar crystal-form PVDF material and the composite thereof are prepared by adding the CTAB playing a remarkable role in nucleation of polyvinylidene fluoride polar crystal forms. The composite can be formed by the aid of various methods (solution method and melting method) and various processing equipment (extruding, injection molding and mould pressing), and the preparation method is simple and convenient.

According to one aspect, the present invention concerns a terahertz modulator (1) intended to be used in a given frequency band of use. The modulator comprises a semi-conductor polar crystal (330) presenting a Reststrahlen band overlapping said frequency band of use and presenting at least one interface with a dielectric medium, coupling means (330) allowing the resanant coupling of an interface phonon polariton (IPhP) supported by said interface and of an incident radiation (2) of pre-determined frequency lying in said frequency band of use and means of control (22) apt to modify the intensity of the coupling between said interface phonon polariton and said incident radiation (2) by modification of the dielectric function of the polar crystal in the Reststrahlen band of the polar crystal (10).

The invention relates to a method of electro-optic Q-switching of a solid laser, and in particular to a method for realizing high repetition frequency electro-optic Q-switching by using a periodic polar crystal as an electro-optic Q switch. The method at least comprises a pumping source, a coupling system and a resonant cavity which form the laser. The resonant cavity comprises a laser medium and an output mirror, wherein two isodirectional polaroids are arranged between the laser medium and the output mirror; and the periodic polar crystal is arranged between the two polaroids. The method is characterized in that voltage is loaded on the periodic polar crystal through a back-pressure type Q switch power supply so that the crystal axial direction of each electric domain just defects to the angle theta capable of realizing oscillation laser Saco filtration, then the polarization direction of the oscillation laser through the periodic polar crystal rotates by 90 degrees, failing to form oscillation through the second isodirectional polaroid; as a result, the energy-level particles on the laser medium are accumulated; when the on-load voltage loses transiently, the resonant cavity starts oscillation rapidly to form laser pulse and output. In the invention, the required on-load voltage is relatively low, therefore the operation of the high repetition frequency electro-optic Q-switching of the solid laser is easily achieved.

Provided is a semiconductor device fabrication apparatus comprising: a filter which contains a polar crystal, and filters pure water or a liquid containing pure water as a solvent; and a working section which has a pressing mechanism configured to apply a pressure to said filter, and supplies the filtered pure water or the filtered liquid containing pure water as a solvent to a surface of an object to be polished or cleaned, thereby performing a polishing process or cleaning process.

The invention provides a battery coating film slurry, a battery diaphragm and secondary battery and respective preparation methods thereof. The preparation of the battery coating film slurry comprisesthe steps: providing a polymerization unit including vinylidene fluoride and a fluorine-containing polymerization unit, providing a nucleating agent and adding the nucleating agent in the polymerization process of the polymerization unit so as to obtain a modified polymer; and preparing the battery coating film slurry based on the modified polymer. With application of the technical scheme, the battery coating film slurry is designed, the non-aqueous system is used, the diaphragm and the pole piece can be bonded together to improve the hardness of the battery, and the crystal form of the prepared polymer is transformed to the polar crystal form, the crystal structure is more perfect, the crystallinity is higher, the swelling ratio is low and the adhesion performance is superior; and the prepared battery has lower internal resistance and better cycling performance. The polymer is dispersed by using the aqueous system so that the shortage of the copolymer prepared by the oil-based systemcan be solved, the advantage of the aqueous polymer coating product can be exerted and the environmental protection effect can be further improved.

The invention provides a method of utilizing a spontaneous polarization built-in electric field in a ZnO single crystal to adjust and control separation efficiency and optic electrochemical property of photon-generated carriers in a photoelectrode of the ZnO single crystal. Through adjusting direction of the polarization built-in electric field in the electrode of the ZnO single crystal, separation efficiency of photon-generated carriers in the electrode of the ZnO single crystal is controlled to regulate and control light current and photoelectric conversion efficiency. When the direction of the built-in electric field in the ZnO single crystal is perpendicular to the surface of the electrode and points to the outer surface (O-SC), light current, quantum conversion efficiency and separation efficiency of carriers in the electrode are effectively enhanced. The method is simple and effective to further improve the separation efficiency and activity of carriers of the photoelectrode of photoelectrochemistry and has potential application value.

The invention discloses a polar crystal La3SbS4OCl2 and a preparation method thereof, and relates to the technical field of intraocular lens, the crystal is a sulfur-oxygen-chlorine mixed anion compound with a non-centrosymmetric structure, the crystal system is a hexagonal crystal system, the space group is P63mc, and the unit cell parameter unit cell volume is prepared in a way that under the protection of inert gas according to the stoichiometric ratio of La3SbS4OCl2, elemental lanthanum, lanthanum trichloride, elemental antimony, antimony trioxide and elemental sulfur are mixed and then put into a quartz tube, vacuumized, heated to 920-980 DEG C, a solid-phase chemical reaction is performed, and cooling is performed, thereby obtaining the product. According to the invention, the anti-laser-damage functional element is utilized to regulate and control the SbS3 triangular pyramid structure units of the polar functional element to realize equidirectional arrangement, so that the spontaneous polarization intensity is increased, the non-centrosymmetric structure is assembled on the molecular level, and the polar crystal La3SbS4OCl2 is successfully synthesized. The polar crystal has strong spontaneous polarization intensity and high laser damage threshold.

A support of two luminous polar crystals is prepared as setting two carrying units with fixed height drop on support, utilizing higher carrying unit to set luminous chip and utilizing relatively lower carrying unit to set static resisting chip to let light source generated by luminous chip free block of static resisting chip.