Overview
Layered Double Hydroxides (LDHs) are a class of ionic lamellar compounds consisting of positively charged brucite-like layers with interlayer anions and water molecules. Their chemical versatility allows for tuning of properties through selection of divalent (e.g., Mg²⁺, Zn²⁺) and trivalent (e.g., Al³⁺, Fe³⁺) metal cations, as well as various interlayer anions (CO₃²⁻, NO₃⁻, etc.). This structural flexibility makes them valuable across multiple industries. First synthesized in the 19th century, modern LDHs are engineered for specific applications. Their unique 'memory effect' - the ability to reconstruct the original layered structure after calcination - is particularly valuable in catalysis and environmental applications. Industrial production typically involves coprecipitation or hydrothermal methods.
Physical and Chemical Properties
LDHs exhibit a characteristic layered structure with a general basal spacing of 7.8-8.2 Å for carbonate forms. Their specific surface area typically ranges from 20-120 m²/g, though this can be increased through exfoliation. The materials show excellent thermal stability up to 200-300°C, with decomposition temperatures depending on composition. A key feature is their anion exchange capacity (1-4 meq/g), allowing replacement of interlayer anions while maintaining the layered structure. The materials are typically basic (pH 8-10 in suspension) and demonstrate interesting intercalation chemistry. Electrical properties range from insulating to semiconducting based on metal ion selection.
Main Applications
In catalysis, LDHs serve as precursors for mixed oxide catalysts after calcination, particularly for base-catalyzed reactions. Their high surface area and tunable acid-base properties make them effective for transesterification and aldol condensation reactions. As flame retardants, they release water and CO₂ endothermically during decomposition. The pharmaceutical industry utilizes LDHs for controlled drug delivery, benefiting from their biocompatibility and pH-responsive release. Environmental applications include phosphate removal in wastewater treatment and heavy metal immobilization. Emerging uses include energy storage (supercapacitors, batteries) and as nanofillers in polymer composites.
Safety and Storage
Most LDHs are classified as low hazard materials, though dust inhalation should be avoided. Material Safety Data Sheets (MSDS) should be consulted for specific compositions. Storage requires protection from moisture and CO₂ exposure to prevent unwanted anion exchange (particularly for nitrate forms). Decomposition products vary by composition but typically include metal oxides and water vapor. Some mixed-metal LDHs may release toxic metal vapors at high temperatures. Standard laboratory precautions (gloves, eye protection) are generally sufficient for handling. Bulk storage should be in polyethylene-lined containers in dry conditions.
B2B Procurement Guide
When procuring LDHs, clearly specify: 1) Metal cation ratio (e.g., Mg/Al = 2:1), 2) Interlayer anion type, 3) Particle size distribution, 4) Surface area requirements, and 5) Any special modifications (organic modification, exfoliation). Technical grades (95-98% purity) are typically sufficient for industrial applications. Lead times vary from 2-8 weeks for custom compositions. Sample quantities (100g-1kg) are often available for testing. For large-volume purchases (>1 ton), consider regional suppliers to minimize transportation costs. Quality control should verify metal content (ICP analysis), crystallinity (XRD), and anion content (CHNS or ion chromatography).
Related Manufacturers
- 主营：ELISA试剂盒、PCR试剂盒、科研试剂
- 主营：试剂盒、人25羟基维生素、人低氧诱导因子
- 主营：检测方、钠尿肽、试剂盒、同源物、ep300检测、结合蛋白、大鼠c-肽(、微球蛋白、抗胰蛋白酶、淋巴瘤因子、蛋白磷酸酶、死亡激动剂、核心域蛋白1、大鼠e选择素、大鼠janus激酶、激活蛋白激酶、大鼠ⅱ型胶原、大鼠ⅳ型胶原、大鼠klotho蛋白、细胞激活因子、大鼠ⅲ型胶原、大鼠nadh脱氢酶1、大鼠ⅵ型胶原α1、elisa 检测试剂盒
- 主营：试剂盒、elisa试剂盒、细胞、pcr试剂盒
- 主营：制氮机、制氧机、制氮设备、高原液氮机、液氮发生器、氮气发生器、液氮机
- 主营：抑制物、糖蛋白、试剂盒、释放因子、人色氨酰、炎性蛋白、刺激因子、生长因子、武装因子、钙黏蛋白、淋巴细胞、成孔蛋白、趋化因子、人促睡眠肽、免疫球蛋白、节苷脂抗体、人精氨酸酶、二聚化蛋白、人β葡糖苷酶、人β内酰胺酶、肝炎病毒抗体、活化黏附因子、凋亡抑制因子、人潜伏膜蛋白、人二氢嘧啶酶
- 主营：DC-DC电源芯片、接口芯片、无线收发芯片、RF滤波器、RS232芯片、RF放大器、音频接口芯片、视频接口芯片、射频卡芯片
- 主营：抗体、酶联免疫试剂盒、elisa试剂盒、pcr试剂盒、核酸试剂盒
- 主营：elisa试剂盒
- 主营：elisa试剂盒、生物试剂、荧光试剂盒、抗体、化学试剂、培养基、标准品、比色法试剂盒
- 主营：elisa试剂盒、试剂盒、抗体
- 主营：传感器、旋转编码器、插针外壳底座、电机、液压缸、连接器、继电器、仪器仪表、madgetech、harting、e+e、s+s regel、esitron、ckd、smc、ems、conforti
- 主营：ELISA试剂盒、PCR试剂盒、生化试剂盒、脂蛋白、关基因、亲环素、钾通道、列抗体、ntp溶液、蛋白酶、脑蛋白、病毒抗、蛋白质、239抗体、dtt溶液、科研试剂
- 主营：Elisa试剂盒、生化试剂盒、蛋白试剂盒、细胞试剂盒
- 主营：试剂盒、ELISA试剂盒、科研ELISA试剂盒、PCR试剂盒、生化试剂盒