CN1260410C - Nickel ammonium sulfate hexahydrate crystal for ultraviolet filter - Google Patents

Abstract

The present invention relates to a hexahydrated nickel ammonium sulfate crystal used for an ultraviolet light filter. The chemical formula of the hexahydrated nickel ammonium sulfate crystal is (NH4)2Ni(SO4)2.6H2O (ANSH for short); the ANSH single crystal is grown by adopting a water solution temperature drop method; secondary distilled water is a crystal growth solvent, and the growth temperature is from 65 DEG C to 30 DEG C; small crystals of spontaneous crystallization are used as seed crystals; the crystal growth speed is controlled within 2 to 3 mm/day, and the crystal rotational speed is 30 revolutions per minute (positive and reverse rotation); and the temperature control precision of a growth groove is 0.05 DEG C. The crystal has the advantages of high transmissivity at 240 nm of an ultraviolet region, 96.06 to 220.6 DEG C of dehydration temperature, good thermal stability and few crystal defects, so the crystal can be used for ultraviolet light filters, light range switches, and ultraviolet light sensors of guided missile defence system alarms.

Description

The nickel ammonium sulfate hexahydrate crystal that is used for ultraviolet filter

Technical field

The invention belongs to chemistry and field of metallurgy, particularly relate to a kind of crystalline material and crystal growth thereof that is used for ultraviolet filter.

Background technology

Childy report Ni (SO in 1961 ₄) ₂6H ₂O crystal (be called for short NSH) and the halogenide KCl:KBr crystal of mixing Pb are made the narrow band filter of UV spectrum district (0.26-0.27 μ m).(KStadrick et al.Acta Cryst.1987, B43:319) report grows with method of evaporation (35 ℃) that 40mm grows, the cross section is the NSH monocrystalline of 25mm to KStadrick et al in 1987.WJPVANENCKEVOPT goes up the Ni (SO that reports with 98% at document " Jounal of Crystal Growth 80 (1987) 91-103 " ₄) ₂6H ₂The O raw material is with falling temperature method (45-36 ℃), through growing the NSH crystal of 3-4cm diameter 4 weeks.We have delivered 3 pieces of papers (Su Genbo, He You equality, α-Ni (SO from 1996-2000 growth of NSH crystalline and performance study ₄) ₂6H ₂O crystal growth and optical property, artificial lens journal, 1998 27 volumes, the 1st phase, 56-59 page or leaf; Su Genbo, He Youping, et al., Directional growth of Cylinder α-NiSO ₄6H ₂O Crystal.J.CrystGrowth, 213 (2000) 99-102; Su Genbo, He You equality are used for the oriented growth of the cylindrical nickel sulfate hexahydrate crystal of wave filter, artificial lens journal, 2000 29 volumes, the 1st phase).May in 1999,4 Japan-Soviet rich people such as grade declared the Chinese invention patent (application number is 99108240.0) of " growth method of cylindrical alpha-nickel sulfate hexahydrate crystal ".Ni (SO ₄) ₂6H ₂O crystal widespread use is done the wave filter and the transmitter of ultraviolet region and commercialization (American I NRAD company product advertising and quotation).NSH is low thermostability (dehydration more than 60 ℃) in the space as the problem of sensor application, is not suitable for the higher Working environment (〉=80 ℃) of guided missile warning especially.

1998 famous u.s.a. military affairs industrial (Northrop Grumman Corpcration) people such as Narsingh B. obtained U.S.'s patent of invention (Singh et al of ultraviolet filter crystal (Crystals for Ultravioletlight filters), United States Patent, Crystals for Ultraviolet light filters, 5,788,765, Aug, 4,1998).This patent mainly is to have invented a kind of new ultraviolet filter crystal material---K ₂Ni (SO ₄) ₂6H ₂O (being called for short KNSH) has the high transparent characteristic of the ultraviolet region similar to the NSH crystal, and thermostability is better than the NSH crystal, still can keep its good materialization and optically filtering performance, lower deliquescence under envrionment temperature 95-110 ℃.Reported the KNSH crystal that from the HCl of 30:70 and water saturation solution (PH＜6), grows 2 cm diameters with aqueous solution cooling method.Plan this crystal and make the ultraviolet filtering sensor application in missile early warning system, its principle such as Fig. 1.This patent is listed 10 protection domains, wherein mentions the ultraviolet filter crystalline and forms and to comprise that the basic metal (M) and the series compound of the six directions water of the vitriol of nickel [are M for the 5th ²⁺(M:Li ⁺, Na ⁺, K ⁺, Rb ⁺, Cs ⁺) Ni (SO ₄) ₂6H ₂O], the thermostability of these compounds is all greater than 85 ℃, and UV-light can both see through.

According to the analysis and research of composition, crystalline structure and the UV spectrum property relationship of molecule, we design a kind of new ultraviolet filter crystalline material-nickel sulfate hexahydrate ammonium (NH ₄) ₂Ni (SO ₄) ₂6H ₂O (being called for short ANSH) is because NH ₄ ⁺Not basic metal, so not at the protection domain of patent (US 5,788,765), ANSH has ultraviolet region to see through and the characteristic of Heat stability is good (＞85 ℃).Relevant ANSH crystalline is reported to (Tahin H et al, A Precise StructureRedetermination of Nickel Ammonium Sulfate HexahydrateNi (H such as Tahin H in 1994 ₂O) ₆2NH ₄2SO ₄, Acta Cryst. (1994), C50 is 668-669) about the mensuration and nineteen sixty-eight V.Ananthan (the VAnenthan avavanan.Studies on theDifractional Spectrum of the SO of ANSH crystalline structure ₄ ^-2Ion in Crystalline M ₂' M " (SO ₄) ₂6H ₂O (M '=K or NH ₄And M "=Mg Zn Ni or Co): observation on theSymmetry of the Sulfate Ion in Crystals.The Journal of ChemicalPhysics 48; 2; 1968,573-581) about the research of ANSH molecular vibration spectrum.At present both at home and abroad still not about the ANSH crystal as reports relevant such as ultraviolet filtering modulator material and crystal growths with the present patent application content.

Summary of the invention

The objective of the invention is to design and develop a kind of new ultraviolet filter crystalline material.Should possess ultraviolet region (～300nm) high permeability and as the ultraviolet filter crystalline material than the high spectral response curve that absorbs of long-wave band; Heat stability is good Working environment＞85 ℃ of comparatively high temps (as can be used for); The quality that grows high optical quality and large size single crystal easily and be easier to carry out the device preparation.(the NH that we design and develop ₄) ₂Ni (SO ₄) ₂6H ₂The new crystal of O (ANSH) has the above-mentioned quality as the ultraviolet filter function, and crystalline UV spectrum characteristic is similar with the KNSH crystal to NSH, and it is close with KNSH that thermostability is better than the NSH crystal.Crystal growth is easier than KNSH crystal, and the KNSH crystal will be grown in the aqueous solution of mixing the HCl solubility promoter, and the ANSH crystal growth is as long as grow in the aqueous solution.These two kinds of process of growth relatively form defective easily in the KNSH crystal growing process and influence crystalline optical quality and utilization ratio, and the ANSH crystal growth becomes more readily available the higher crystal of quality.

The chemical formula of the crystalline material nickel sulfate hexahydrate ammonium that the ultraviolet filter that we invent is used is (NH ₄) ₂Ni (SO ₄) ₂6H ₂O (being called for short ANSH).Its growing method is as follows:

(1) determine the solubleness of ANSH in water: usefulness saturated solution weighting method is measured the solubility curve of ANSH in water, simulates solubleness expression formula and is: S=a+bt+ct ², a=0.07958, b=4.74331 * 10 ^-4, c=3.72503 * 10 ^-5, solubleness S (ANSH g/100gH ₂O).More moderate and solubility temperature coefficient is also bigger from the visible ANSH solubleness of Fig. 4, so be fit to adopt aqueous solution cooling method growth ANSH monocrystalline.

(2) the ANSH crystal growth temperature can be selected from 65 ℃ to 30 ℃.

(3) preparation of ANSH saturated solution: according to the saturated solution of (1) solubleness expression formula preparation ANSH, the synthetic method of ANSH raw material is 1: 1 Ni (SO with analytically pure mol ratio ₄) 6H ₂O and (NH ₄) ₂SO ₄Obtain glaucous ANSH granular crystal 60 ℃ of following evaporations after the heating for dissolving in distilled water, the PH of saturated solution is 4-5.

(4) small-crystalline that adopts spontaneous crystallization is as seed crystal, and the cooling amount according to degree of the separating out control crystal growth groove of ANSH crystalline growth surface and saturated solution is grown up the ANSH crystal gradually.

(5) the crystalline velocity of rotation is 30 rev/mins (rotatings), and the temperature-controlled precision of growth groove is 0.05 ℃.

We with the PE-lambda900 spectrophotometer ANSH crystalline see through the spectrum (see figure 2) and show from 190-1500nm have four to see through the peak, transmitance height at ultraviolet region 240nm place, there are two to see through the peak at visible region, also occur one in the near-infrared region and see through the peak.Illustrate that the ANSH crystal can pass through UV-light, be suitable as the ultraviolet filtering modulator material, its a plurality of characteristics that see through the peak can be used for the wave selector material of light.

We have measured its dehydration temperaturre with Delt Series TGA7 thermal analyzer is 96.06-220.6 ℃ of (see figure 3), than high nearly 20 ℃ of the dehydration temperaturre of NSH.As seen ANSH crystalline thermal stability is better than NSH crystal, and is close with the KNSH crystal.Illustrate that the ANSH crystal is being stable more than 85 ℃, be applicable to that the envrionment temperature of high-altitude vehicle is used, can be as the missile defense systems warning howler as ultraviolet light transducer.

The present invention compares useful effect such as the following table that is had with background technology:

	Background technology (KNSH crystal)	The present invention's (ANSH crystal)
			Thermostability (dehydration temperaturre ℃)	97.23-227.62	96.06-220.6
Ultraviolet spectrum characteristic (240nm)	High permeability	High permeability
			The crystal growth solvent	Two component H 2O+HCl	Single-component H 2O
Lattice defect	Many	Few

Because the KNSH crystal growing process more easily produces tangible macroscopical sector-shaped defect district, influence the utilization ratio that crystalline optical property and crystal are made device to a certain extent.ANSH crystalline UV spectrum is similar to KNSH with thermostability, is easier to obtain the high crystalline material of optical quality in crystal growth.

Description of drawings

Below accompanying drawing is done concise and to the point drawing explanation:

Fig. 1 is the synoptic diagram that the ultraviolet crystal is applied to missile defense systems;

Fig. 2 is the spectrum that sees through of ANSH crystal (measurement thickness is 7mm);

Fig. 3 is an ANSH crystalline thermogravimetric analysis spectrum;

Fig. 4 is the solubility curve of ANSH crystal in water;

Fig. 5 is the photo of ANSH monocrystalline.

Embodiment

Now illustrate and realize best way of the present invention:

Raw material: homemade analytical reagent NiSO ₄6H ₂O and (NH ₄) ₂SO ₄And redistilled water;

Growth groove: 1000cm ³K9 glass educate brilliant bottle, temperature control precision ± 0.05 ℃;

The preparation of solution: according to 55 ℃ of saturated solutions of above-mentioned solubleness expression formula preparation ANSH, measure the temperature of saturation of solution with eddy-current method, the solution 10 ℃ of after-filtration that heat up are removed insoluble substance, and filtrate is slowly reduced to 57 ℃ at 65 ℃ overheated after one day;

Crystal growth: the small-crystalline about 5mm is bound with filament, be fixed on the glass seed crystal rotary bar by plastic casing, after preheating, move into above-mentioned 57 ℃ growth solution, and cool the temperature to saturation point, control the crystalline speed of growth at 2-3mm/ days with the cooling amount, Crystal Rotation speed (positive dirction) is 30 rev/mins, and through about one month growth cycle, can obtain bore was the transparent complete ANSH monocrystalline (shown in the photo of Fig. 5) of several centimetres of magnitudes.

Claims (1)

1. a growth method that is used for the nickel ammonium sulfate hexahydrate crystal of ultraviolet filter adopts aqueous solution cooling method growth ANSH monocrystalline, it is characterized in that: the Ni (SO that with mol ratio is 1: 1 ₄) 6H ₂O and (NH ₄) ₂SO ₄The growth raw material of synthetic ANSH is the crystal growth solvent with the redistilled water, is mixed with the saturated solution that PH is 4-5; The crystalline growth temperature is from 65 ℃ to 30 ℃; The small-crystalline that adopts spontaneous crystallization is as seed crystal; The crystalline speed of growth was controlled at 2-3mm/ days; The crystalline velocity of rotation is 30 rev/mins (rotatings); The temperature-controlled precision of growth groove is 0.05 ℃.

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