The sonoluminescence generated in water with pulsed 515 kHz ultrasound has been studied in the presence of different chain length (C1−C5) aliphatic alcohols and the surfactants sodium dodecyl sulfate (SDS), dodecyltrimethylammonium chloride (DTAC), and N-dodecyl-N,N-dimethyl-3-ammonio-1-propanesulfonate (DAPS). The ultrasound pulse widths used ranged from 1 to 10 ms, with duty cycles (on/off ratios) of 1:3 to 1:9. It was found that the sonoluminescence from the initial pulses was very low but increased in intensity and reached a maximum after 20−50 pulses, for all systems studied, depending on the pulse width and duty cycle. In the presence of alcohol the maximum signal decreased with increasing alcohol concentration, and the signal decline was more pronounced with increasing chain length of the alcohol. A good correlation was found to exist between the decline in the sonoluminescence signal and the Gibbs surface excess of the alcohol at the air/water interface. In the presence of SDS (an anionic surfactant) and DTAC (a cationic surfactant), quite different behavior was observed. At low concentrations of these two surfactants the maximum signal was significantly enhanced over that obtained in pure water, reaching a maximum at about 1 mM of surfactant. At higher concentrations the signal decreased again reaching a limiting value similar to that obtained in pure water. The sonoluminescence signal in DAPS (a zwitterionic surfactant) solutions remained much the same as in pure water. On the addition of 0.1 M NaCl to the three different types of surfactant solutions, the intensities of the emission signals obtained were essentially the same as in pure water. Possible mechanisms responsible for the different behavior in the sonoluminescence signal in the presence of the alcohols and surfactants are discussed.

Molecular layer deposition (MLD) techniques were used to grow titanium-containing hybrid organic−inorganic films known as "titanicones" using titanium tetrachloride (TiCl 4 ) and either ethylene glycol (EG) or glycerol (GL). The surface chemistry for titanicone MLD was self-limiting versus TiCl 4 and either EG or GL exposures. Quartz crystal microbalance (QCM) measurements observed a film growth rate of ∼83 ng/cm 2 /cycle using TiCl 4 and EG from 90 to 115 °C. The growth rate then decreased significantly at 135 °C. X-ray reflectivity (XRR) studies yielded a growth rate of ∼4.5 Å/cycle with a constant density of ∼1.8 g/cm 3 from 90 to 115 °C. The growth rate measured using XRR also decreased to 1.5 Å/cycle at 135 °C. Titanicone films were grown using TiCl 4 and GL at higher temperatures between 130 and 210 °C. GL should increase the bridging between the polymer chains in the titanicone film and change film properties and improve film stability. The film growth rates decreased with temperature from 49 ng/cm 2 /cycle at 130 °C to 34 ng/cm 2 /cycle at 210 °C. XRR studies were consistent with a temperature-dependent film growth and measured growth rates of 2.8 Å/cycle at 130 °C and 2.1 Å/cycle at 210 °C. Nanoindentation experiments revealed that the elastic modulus and hardness of the titanicone films grown using GL were much higher than titanicone films grown using EG. Annealing the titanicone films to 600 °C in air removed the carbon constituents and yielded TiO 2 films with a density of ∼3.3 g/cm 3 that is slightly higher than the density of TiO 2 ALD films grown at 115 °C. The titanicone films absorbed light in the ultraviolet, and the absorption threshold was consistent with an optical bandgap of ∼3.6 eV. Prolonged ultraviolet exposures on the titanicone films produced TiO 2 films with a low density of 2.7 g/cm 3 .

Molecular layer deposition (MLD) is a useful technique for fabricating hybrid organic‐inorganic thin films. MLD allows for the growth of ultrathin and conformal films using sequential, self‐limiting reactions. This article focuses on the MLD of hybrid organic‐inorganic films grown using metal precursors and various organic alcohols that yield metal alkoxide films. This family of metal alkoxides can be described as “metalcones”. Many metalcones are possible, such as the “alucones” and “zincones” based on the reaction of trimethylaluminum and diethylzinc, respectively, with various organic diols such as ethylene glycol. Alloys of the various metalcones with their parent metal oxide atomic layer deposition (ALD) films can also be fabricated that have an organic‐inorganic composition that can be adjusted by controlling the relative number of ALD and MLD cycles. These metalcone alloys have tunable chemical, optical, mechanical, and electrical properties that may be useful for designing various functional films. The metalcone hybrid organic‐inorganic materials offer a new tool set for engineering thin film properties.

Hybrid organic-inorganic films can be deposited using atomic layer deposition (ALD) and molecular layer deposition (MLD) techniques. A special set of hybrid organic-inorganic films based on metal precursors and various organic alcohols yields metal alkoxide films that can be described as "metalcones." Many metalcone films are possible such as the "alucones" and "zincones" based on the reaction of trimethylaluminum and diethylzinc, respectively, with various organic alcohols such as ethylene glycol (EG). This paper reviews the previous work on metalcone MLD and discusses a variety of new metalcone systems. "Titanicones" are grown using TiCl4 and glycerol or EG and "zircones" are grown using zirconium tetra-tert-butoxide and EG. In addition, the organic alcohol can also be varied to change the properties within one metalcone family. For example, the glycerol triol precursor allows for more cross-linking and higher toughness in alucones than the EG diol precursor. Alloys can also be formed by combining metalcone MLD and metal oxide ALD. By varying the relative number of cycles of MLD and ALD, the composition and properties of the hybrid organic-inorganic films can be tuned from pure metalcone MLD to pure metal oxide ALD.

Hybrid organic-inorganic films were grown by molecular layer deposition (MLD) with a three-step ABC reaction sequence using (A) trimethylaluminum (TMA), (B) ethanolamine (EA), and (C) maleic anhydride (MA) at 90 °C. Very large steady state mass gains of 1854-4220 ng/(cm(2) cycle) were measured depending on reaction conditions. These mass gains are much larger than typical mass gains for surface reactions. The quartz crystal microbalance (QCM) mass profiles during the TMA reaction were consistent with TMA diffusion into and out of the ABC films. The ABC mass gains per cycle also displayed a strong dependence on the TMA dose and purge times that was consistent with the effects of TMA diffusion. Multiple dose experiments conducted at 130 °C revealed that the ABC reactions were self-limiting for thin ABC films. For thicker ABC films, increased TMA diffusion into the ABC film led to non-self-limiting behavior. Numerical modeling assuming Fickian diffusion for TMA diffusing into and out of the ABC film could fit the QCM mass profiles. The results all indicate that TMA diffusion into the ABC MLD film plays a key role in the thin film growth. In addition, X-ray reflectivity (XRR) measurements revealed that the ABC films were exceptionally smooth.