هيدروكسيد الألومنيوم

هذا المقال هو عن Al(OH)3. إذا كنت تريد AlOH، انظر aluminium monohydroxide.
هيدروكسيد الألومنيوم
Unit cell ball and stick model of aluminium hydroxide
Sample of aluminium hydroxide in a vial
الأسماء
اسم أيوپاك المفضل
Aluminium hydroxide
اسم أيوپاك النظامي
Aluminium(3+) trioxidanide
أسماء أخرى
Aluminic acid

Aluminic hydroxide
Aluminium(III) hydroxide
Aluminium hydroxide
Aluminum trihydroxide
Hydrated alumina

Orthoaluminic acid
المُعرِّفات
رقم CAS
3D model (JSmol)
ChEBI
ChEMBL
ChemSpider
DrugBank
ECHA InfoCard 100.040.433 Edit this at Wikidata
KEGG
رقم RTECS
  • BD0940000
UNII
الخصائص
الصيغة الجزيئية Al(OH)3
كتلة مولية 78.00 g/mol
المظهر White amorphous powder
الكثافة 2.42 g/cm3, solid
نقطة الانصهار
قابلية الذوبان في الماء 0.0001 g/100 mL
نتاج قابلية الذوبان، Ksp 3×10−34
قابلية الذوبان soluble in acids and alkalis
الحموضة (pKa) >7
نقطة تساوي الكهربية 7.7
الكيمياء الحرارية
الإنتالپية المعيارية
للتشكل ΔfHo298 		−1277 kJ·mol−1
علم الأدوية[1]
A02AB01 (WHO)
المخاطر
صفحة بيانات السلامة External MSDS
ن.م.ع. مخطط تصويري The exclamation-mark pictogram in the Globally Harmonized System of Classification and Labelling of Chemicals (GHS)
H319, H335
P261, P264, P271, P280, P304+P340, P305+P351+P338, P312, P337+P313
NFPA 704 (معيـَّن النار)
Flammability code 0: لن يشتعل. مثل الماءHealth code 1: التعرض سيتسبب في تهيجاً ولكن لا يترك سوى جروح طفيفة باقية. مثل زيت الترپنتينReactivity code 0: مستقر في العادة، حتى تحت ظروف التعرض للنار، ولا يتفاعل مع الماء. مثل النيتروجين السائلSpecial hazards (white): no codeNFPA 704 four-colored diamond
0
1
0
نقطة الوميض Non-flammable
الجرعة أو التركيز القاتل (LD, LC):
>5000 mg/kg (rat, oral)
مركبات ذا علاقة
None
مركـّبات ذات علاقة
 أكسيد الصوديوم,
أكسيد هيدروكسيد الألومنيوم
ما لم يُذكر غير ذلك، البيانات المعطاة للمواد في حالاتهم العيارية (عند 25 °س [77 °ف]، 100 kPa).
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مراجع الجدول

هيدروكسيد الألمنيوم Aluminium hydroxide ، صيغته:‏Al(OH)3‎ . ويتواجد في الطبيعة كمعدن گيبسيت gibbsite (الذي يُعرف أيضاً بإسم هيدرارگيليت) و its three much rarer polymorphs: bayerite, doyleite, and nordstrandite. Aluminium hydroxide is amphoteric, i.e., it has both basic and acidic properties. Closely related are أكسيد هيدروكسيد الألومنيوم، AlO(OH), and aluminium oxide or alumina (Al2O3), the latter of which is also amphoteric. These compounds together are the major components of the aluminium ore bauxite.

يتمتع بتأثير مشابه لهيدروكسيد المغنسيوم من حيث قابيلته للاتحاد مع حمض كلور الماء فيخفف بذلك من تأثير هذا الحمض المخرش لغشاء المعدة المخاطي.لذلك يعتبر هيدروكسيد الالمنيوم مضاد حموضة.

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البنية

Al(OH)3 is built up of double layers of hydroxyl groups with aluminium ions occupying two-thirds of the octahedral holes between the two layers.[2][3] Four polymorphs are recognized.[4] All feature layers of octahedral aluminium hydroxide units, with hydrogen bonds between the layers. The polymorphs differ in terms of the stacking of the layers. All forms of Al(OH)3 crystals are hexagonal قالب:Disputed inline:

Hydrargillite, once thought to be aluminium hydroxide, is an aluminium phosphate. Nonetheless, both gibbsite and hydrargillite refer to the same polymorphism of aluminium hydroxide, with gibbsite used most commonly in the United States and hydrargillite used more often in Europe. Hydrargillite is named after the Greek words for water (hydra) and clay (argylles).


الخصائص

Aluminium hydroxide is amphoteric. In acid, it acts as a Brønsted–Lowry base. It neutralizes the acid, yielding a salt:[6]

3 HCl + Al(OH)3 → AlCl3 + 3 H2O

In bases, it acts as a Lewis acid by binding hydroxide ions:[6]

Al(OH)3 + OH− → Al(OH)4−

الانتاج

Red mud reservoirs (this one in Stade, Germany) contain the corrosive residues from the production of aluminum hydroxide.

Virtually all the aluminium hydroxide used commercially is manufactured by the Bayer process[7] which involves dissolving bauxite in sodium hydroxide at temperatures up to 270 °C (518 °F). The waste solid, bauxite tailings, is removed and aluminium hydroxide is precipitated from the remaining solution of sodium aluminate. This aluminium hydroxide can be converted to aluminium oxide or alumina by calcination.

The residue or bauxite tailings, which is mostly iron oxide, is highly caustic due to residual sodium hydroxide. It was historically stored in lagoons; this led to the Ajka alumina plant accident in 2010 in Hungary, where a dam bursting led to the drowning of nine people. An additional 122 sought treatment for chemical burns. The mud contaminated 40 square kilometres (15 sq mi) of land and reached the Danube. While the mud was considered non-toxic due to low levels of heavy metals, the associated slurry had a pH of 13.[8]

الاستخدامات

Fire retardant filler

Aluminium hydroxide also finds use as a fire retardant filler for polymer applications. It is selected for these applications because it is colorless (like most polymers), inexpensive, and has good fire retardant properties.[9] Magnesium hydroxide and mixtures of huntite and hydromagnesite are used similarly[10][11][12][13][14] It decomposes at about 180 °C (356 °F), absorbing a considerable amount of heat in the process and giving off water vapour. In addition to behaving as a fire retardant, it is very effective as a smoke suppressant in a wide range of polymers, most especially in polyesters, acrylics, ethylene vinyl acetate, epoxies, PVC and rubber.[15]

Precursor to Al compounds

Aluminium hydroxide is a feedstock for the manufacture of other aluminium compounds: speciality calcined aluminas, aluminium sulfate, polyaluminium chloride, aluminium chloride, zeolites, sodium aluminate, activated alumina, and aluminium nitrate.[3]

Freshly precipitated aluminium hydroxide forms gels, which are the basis for the application of aluminium salts as flocculants in water purification. This gel crystallizes with time. Aluminium hydroxide gels can be dehydrated (e.g. using water-miscible non-aqueous solvents like ethanol) to form an amorphous aluminium hydroxide powder, which is readily soluble in acids. Heating converts it to activated aluminas, which are used as desiccants, adsorbent in gas purification, and catalyst supports.[9]

الصيدلانيات

Under the generic name "algeldrate", aluminium hydroxide is used as an antacid in humans and animals (mainly cats and dogs). It is preferred over other alternatives such as sodium bicarbonate because Al(OH)3, being insoluble, does not increase the pH of stomach above 7 and hence, does not trigger secretion of excess acid by the stomach. Brand names include Alu-Cap, Aludrox, Gaviscon or Pepsamar. It reacts with excess acid in the stomach, reducing the acidity of the stomach content,[16][17] which may relieve the symptoms of ulcers, heartburn or dyspepsia. Such products can cause constipation, because the aluminium ions inhibit the contractions of smooth muscle cells in the gastrointestinal tract, slowing peristalsis and lengthening the time needed for stool to pass through the colon.[18] Some such products are formulated to minimize such effects through the inclusion of equal concentrations of magnesium hydroxide or magnesium carbonate, which have counterbalancing laxative effects.[19]

This compound is also used to control hyperphosphatemia (elevated phosphate, or phosphorus, levels in the blood) in people and animals suffering from kidney failure. Normally, the kidneys filter excess phosphate out from the blood, but kidney failure can cause phosphate to accumulate. The aluminium salt, when ingested, binds to phosphate in the intestines and reduce the amount of phosphorus that can be absorbed.[20][21]

Precipitated aluminium hydroxide is included as an adjuvant in some vaccines (e.g. anthrax vaccine). One of the well-known brands of aluminium hydroxide adjuvant is Alhydrogel, made by Brenntag Biosector.[22][استشهاد ناقص][dead link] Since it absorbs protein well, it also functions to stabilize vaccines by preventing the proteins in the vaccine from precipitating or sticking to the walls of the container during storage. Aluminium hydroxide is sometimes called "alum", a term generally reserved for one of several sulfates.[بحاجة لمصدر]

Vaccine formulations containing aluminium hydroxide stimulate the immune system by inducing the release of uric acid, an immunological danger signal. This strongly attracts certain types of monocytes which differentiate into dendritic cells. The dendritic cells pick up the antigen, carry it to lymph nodes, and stimulate T cells and B cells.[23] It appears to contribute to induction of a good Th2 response, so is useful for immunizing against pathogens that are blocked by antibodies. However, it has little capacity to stimulate cellular (Th1) immune responses, important for protection against many pathogens,[24] nor is it useful when the antigen is peptide-based.[25]

السلامة

In the 1960s and 1970s it was speculated that aluminium was related to various neurological disorders, including Alzheimer's disease.[26][27] Since then, multiple epidemiological studies have found no connection between exposure to environmental or swallowed aluminium and neurological disorders, though injected aluminium was not looked at in these studies.[28][29][30]

الآثار الجانبية

يتميز بتأثيره الخافض للفوسفات في الدم. كما يودي الى زيادة تركيز الألمنيوم في الدم الذي يترافق باضطرابات دماغية وفقر دم. كما يسبب امساكا وقد تسبب الجرعات الكبيرة انسدادا معويا.

الأشكال الصيدلانية

يعطى بشكل اقراص تحتوي على٥٠٠ملغ أو بحالة معلق تركيزه:٦-٦.٤ملغ/مل.

المصادر

  • الكيمياء الصيدلية: فيصل الجندي، سامر حيدر


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المراجع

  1. ^ Black, Ronald A.; Hill, D. Ashley (15 يونيو 2003). "Over-the-Counter Medications in Pregnancy". American Family Physician. 67 (12): 2517–2524. ISSN 0002-838X. PMID 12825840. Retrieved 1 يوليو 2017.
  2. ^ قالب:Wells4th
  3. ^ أ ب Evans, K. A. (1993). "Properties and uses of aluminium oxides and aluminium hydroxides". In A. J. Downs (ed.). Chemistry of aluminium, gallium, indium, and thallium (1st ed.). London; New York: Blackie Academic & Professional. ISBN 9780751401035.
  4. ^ Karamalidis, A. K.; Dzombak D. A. (2010). Surface Complexation Modeling: Gibbsite. John Wiley & Sons. pp. 15–17. ISBN 978-0-470-58768-3.
  5. ^ أ ب ت Wefers, Karl; Misra, Chanakya (1987). Oxides and hydroxides of aluminum. Alcoa Research Laboratories. p. 2. OCLC 894928306.
  6. ^ أ ب Boundless (26 يوليو 2016). "Basic and Amphoteric Hydroxides". Boundless Chemistry. Archived from the original on 22 أغسطس 2017. Retrieved 2 يوليو 2017.
  7. ^ Hind, AR; Bhargava SK; Grocott SC (1999). "The Surface Chemistry of Bayer Process Solids: A Review". Colloids Surf Physiochem Eng Aspects. 146 (1–3): 359–74. doi:10.1016/S0927-7757(98)00798-5.
  8. ^ "Hungary Battles to Stem Torrent of Toxic Sludge". BBC News Website. 5 أكتوبر 2010.
  9. ^ أ ب Hudson, L. Keith; Misra, Chanakya; Perrotta, Anthony J.; Wefers, Karl; Williams, F. S. (2000). "Aluminum Oxide". Ullmann's Encyclopedia of Industrial Chemistry. Weinheim: Wiley-VCH. doi:10.1002/14356007.a01_557. {{cite encyclopedia}}: Cite has empty unknown parameter: |authors= (help)
  10. ^ Hollingbery, LA; Hull TR (2010). "The Fire Retardant Behaviour of Huntite and Hydromagnesite - A Review" (PDF). Polymer Degradation and Stability. 95 (12): 2213–2225. doi:10.1016/j.polymdegradstab.2010.08.019.
  11. ^ Hollingbery, LA; Hull TR (2010). "The Thermal Decomposition of Huntite and Hydromagnesite - A Review" (PDF). Thermochimica Acta. 509 (1–2): 1–11. doi:10.1016/j.tca.2010.06.012.
  12. ^ Hollingbery, LA; Hull TR (2012). "The Fire Retardant Effects of Huntite in Natural Mixtures with Hydromagnesite" (PDF). Polymer Degradation and Stability. 97 (4): 504–512. doi:10.1016/j.polymdegradstab.2012.01.024.
  13. ^ Hollingbery, LA; Hull TR (2012). "The Thermal Decomposition of Natural Mixtures of Huntite and Hydromagnesite" (PDF). Thermochimica Acta. 528: 45–52. doi:10.1016/j.tca.2011.11.002.
  14. ^ Hull, TR; Witkowski A; Hollingbery LA (2011). "Fire Retardant Action of Mineral Fillers" (PDF). Polymer Degradation and Stability. 96 (8): 1462–1469. doi:10.1016/j.polymdegradstab.2011.05.006.
  15. ^ Huber Engineered Materials. "Huber Non-Halogen Fire Retardant Additives" (PDF). Retrieved 3 يوليو 2017.
  16. ^ Galbraith, A; Bullock, S; Manias, E; Hunt, B; Richards, A (1999). Fundamentals of pharmacology: a text for nurses and health professionals. Harlow: Pearson. p. 482.
  17. ^ Papich, Mark G. (2007). "Aluminum Hydroxide and Aluminum Carbonate". Saunders Handbook of Veterinary Drugs (2nd ed.). St. Louis, Mo: Saunders/Elsevier. pp. 15–16. ISBN 9781416028888.
  18. ^ Washington, Neena (2 أغسطس 1991). Antacids and Anti Reflux Agents. Boca Raton, FL: CRC Press. p. 10. ISBN 978-0-8493-5444-1.
  19. ^ Bill, Robert L. (1 سبتمبر 2016). Clinical Pharmacology and Therapeutics for Veterinary Technicians - E-Book. Elsevier Health Sciences. p. 105. ISBN 9780323444026.
  20. ^ Plumb, Donald C. (2011). "Aluminum Hydroxide". Plumb's Veterinary Drug Handbook (7th ed.). Stockholm, Wisconsin; Ames, Iowa: Wiley. pp. 36–37. ISBN 9780470959640.
  21. ^ Lifelearn Inc. (1 نوفمبر 2010). "Aluminum Hydroxide". Know Your Pet. Retrieved 30 يونيو 2017.
  22. ^ "About Brenntag Biosector - Brenntag". brenntag.com. Retrieved 19 أبريل 2018.
  23. ^ Kool, M; Soullié T; van Nimwegen M; Willart MA; Muskens F; Jung S; Hoogsteden HC; Hammad H; Lambrecht BN (24 مارس 2008). "Alum adjuvant boosts adaptive immunity by inducing uric acid and activating inflammatory dendritic cells". J Exp Med. 205 (4): 869–82. doi:10.1084/jem.20071087. PMC 2807488. PMID 18362170.
  24. ^ Petrovsky N, Aguilar JC (2004). "Vaccine adjuvants: current state and future trends". Immunology & Cell Biology. 82 (5): 488–96. doi:10.1111/j.0818-9641.2004.01272.x. PMID 15479434. S2CID 154670.
  25. ^ Cranage, MP; Robinson A (2003). Robinson A; Hudson MJ; Cranage MP (eds.). Vaccine Protocols - Volume 87 of Methods in Molecular Medicine Biomed Protocols (2nd ed.). Springer. p. 176. ISBN 978-1-59259-399-6.
  26. ^ "Alzheimer's Myth's". Alzheimer's Association. Retrieved 29 يوليو 2012.
  27. ^ Khan, A (1 سبتمبر 2008). "Aluminium and Alzheimer's disease". Alzheimer's Society. Archived from the original on 11 مارس 2012. Retrieved 8 مارس 2012.
  28. ^ Rondeau V (2002). "A review of epidemiologic studies on aluminum and silica in relation to Alzheimer's disease and associated disorders". Rev Environ Health. 17 (2): 107–21. doi:10.1515/REVEH.2002.17.2.107. PMC 4764671. PMID 12222737.
  29. ^ Martyn CN, Coggon DN, Inskip H, Lacey RF, Young WF (مايو 1997). "Aluminum concentrations in drinking water and risk of Alzheimer's disease". Epidemiology. 8 (3): 281–6. doi:10.1097/00001648-199705000-00009. JSTOR 3702254. PMID 9115023. S2CID 32190038.
  30. ^ Graves AB, Rosner D, Echeverria D, Mortimer JA, Larson EB (سبتمبر 1998). "Occupational exposures to solvents and aluminium and estimated risk of Alzheimer's disease". Occup Environ Med. 55 (9): 627–33. doi:10.1136/oem.55.9.627. PMC 1757634. PMID 9861186.

وصلات خارجية

قالب:Drugs for treatment of hyperkalemia and hyperphosphatemia

الكلمات الدالة:
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