Zongshi Li

Synthesis and characterization of a series of carbamate-linked cationic lipids for gene delivery

A series of pH-sensitive lipids, 1a-h [(2,3-bis-alkyl-carbamoyloxy-propyl)-trialkylammonium halide] and 2a-d (1-dimethylamino-2,3-bis-alkylcarbamoyloxy-propane), with carbamate linkages between the hydrocarbon chains and an ammonium or tertiary amine head, were synthesized for liposome-mediated gene delivery. The variable length of the carbon chains and the quaternary ammonium or neutral tertiary amine heads allowed us to identify the structure-function relationship showing how these factors would affect cationic lipid in gene delivery performance.

Structure–Function Relationship Research of Glycerol Backbone-Based Cationic Lipids for Gene Delivery

Transfection activities of two series of synthetic glycerol backbone‐based cationic lipids were studied as gene delivery carriers. The variable length of hydrocarbon chains, diverse quaternary ammonium heads, different linkage, as well as alternative anion combined with them allowed to find how these factors affect cationic lipids on their gene delivery performance. The structure–function relationship of the synthetic glycerol backbone‐based cationic lipids was discussed, and the transfection efficiency of some of the cationic liposomes was superior or parallel to that of two commercial transfection agents.

Dynamic Interfacial Tension Between Crude Oil and Novel Surfactant Flooding Systems Without Alkali

Abstract The surface tensions of tetradecylmethylnaphthalene sulfonate (TMNS) surfactant aqueous solution and the dynamic interfacial tension (DIT) between crude oil, from Shandong Shengli oil field of China, and the surfactant solution without alkaline, was measured. Results indicate that the TMNS surfactant had great capability and efficiency of lowering the solution surface tension. The critical micelle concentration (cmc) is 0.001 mass% and the surface tension at this concentration is 28.19 mN.m−1. It was also found that the TMNS surfactant is greatly effective in reducing the interfacial tensions and can lower the tension of crude oil-water interface to ultra-low at very low concentration, 0.002 mass%, without alkali and other additives. Both chromatogram separation of flooding and breakage of stratum are avoided effectively. The lower salinity is favorable for the flooding systems, lowering the DIT. The synthesized TMNS surfactant flooding systems without alkali and sodium chloride, decreasing the cost of oil recovery and avoiding the stratum being destroyed, would have a great prospect for enhanced oil recovery (EOR).

Dynamic Interfacial Behavior of Decyl Methylnaphthalene Sulfonate Surfactants for Enhanced Oil Recovery

Abstract The high purity decyl methylnaphthalene sulfonate (DMNS) was synthesized, the purity was determined by HPLC and the structure was confirmed by IR, UV and ESI-MS. Dynamic interfacial tensions (DIT) between DMNS flooding systems and crude oil were measured and the effects of sodium carbonate concentration, surfactant concentration and sodium chloride concentration on the DIT behaviors were investigated. Its found that the surfactant concentration, alkali concentration and the salinity have obvious influences on DIT behaviors. DMNS possessed outstanding capacity and efficiency of lowering the DIT between oil and water. The minimum dynamic interfacial tension could reach 6.35×10−6 mNm−1 at a lowconcentration for added surfactant. DMNS might be used in Enhanced Oil Recovery with lowcosts and high efficiency.

Synthetic Diether‐linked Cationic Lipids for Gene Delivery

Quaternary ammonium lipids 2a–p, with diether linkages between hydrocarbon chains and their ammonium headgroups, were synthesized as potential vectors for cationic liposome‐mediated gene delivery. Varying the length of carbon chains and quaternary ammonium heads as well as different anionic complexes will enable the study of the structure–function relationships of these cationic lipids in terms of gene delivery properties.

Synthesis and Interfacial Tension Behavior of Heavy Alkyl Benzene Sulfonates

Abstract Heavy alkyl benzene sulfonates (HABS) were synthesized, and their interfacial tensions were measured and compared with those of petroleum sulfonates ORS-41. Effects of their coupling with lignosulfonate were also studied. The results showed that HABS exhibited good interfacial activities and the system of HABS blending with LS displayed better interfacial activities than ORS-41 and therefore reduced the prime cost. Their best proportions of synergism were from 3:1 to 4:1. HABS might be a more promising alkali-surfactant-polymer (ASP) flooding agent.

1-Phenylalkane Sulfonates for Studying Interfacial Tensions

Abstract A series of 1-phenylalkane sulfonates with high purity were synthesized through a simple and effective way. Interfacial tension (IFT) of 1-phenylalkane sulfonates against crude oil from Daqing oil field in China was investigated, interfacial tension minima were observed with changes of surfactant concentrations and time. Alkali concentrations where lowest interfacial tensions were achieved moved to low regions by increasing the chain length of 1-phenylalkane sulfonates, namely, 1-phenyldodecane sulfonate at about 2.2%, 1-phenyltetradecane sulfonate at about 0.6%, 1-phenylhexadecane sulfonate at about 0.3%. No minima were observed when interfacial tensions of pure 1-phenylalkane sulfonates against alkanes were measured. The phenomenon is quite distinct from that of 1-phenylalkane sulfontes against crude oil.

Synthesis and Surface Active Properties of Novel Nonionic Aryl Oleic Diethanolamide Surfactants

Abstract A series of novel aryl oleic diethanolamide (AOD) surfactants with different hydrophobic groups were synthesized. An aromatic ring introduced to a long alkyl chain had a significant effect on reducing water surface tension. The critical micelle concentration (CMC) and the surface tension (γ cmc ) at the CMC were investigated. The CMC was 4.56 × 10−8 mol/L to 5.83 × 10−6 mol/L for AOD1:1 (molar ratio of aryl oleic acid: diethanolamide = 1:1) and corresponding γ cmc was 36.4 mN/m to 39.3 mN/m. The CMC of AOD1:2 (molar ratio of aryl oleic acid: diethanolamide = 1:2) were in 1.21 × 10−7–9.98 × 10−6 mol/L and γ cmc were in 31.6–34.4 mN/m.

Synthesis and Surface Activity of Alkyl-Methylnaphthalene Sulfonate Surfactants

A series of alkyl methylnaphthalene sulfonate surfactants (AMNS) were synthesized and their structures were confirmed by IR, UV and ESI-MS. The surface tension measurements were performed by the ring method. The effects of the alkyl side chains on critical micelle concentrations (cmc), and the surface tensions (γ cmc ) at cmc and C 20 were investigated. The results indicated that the anionic surfactants prepared exhibited good surface activity. The study of adsorption at the surfaces of aqueous solution and the thermodynamics of the surfactant micelles showed that both the alkyl side chains and the aromatic rings were attributed to the surface activity.

Liquid Phase Benzoylation of Naphthalene over Hβ Zeolite for Synthesizing 2-Benzoylnaphthalene

Abstract It is economical to develop green synthetic process by using the by-product of Heavy-oil Contact Cracking Process (HCC) to form 2-benzoylnaphthalene. Benzoylation of naphthalene with benzoyl chloride was carried out over five kinds of zeolites. And Hβ zeolite represented very high catalytic activity and good selectivity for 2-benzoylnaphthalene. The benzoylation over Hβ zeolite for producing 2-benzoylnaphthalene was studied in detail by a series of experiments on relative influencing factors. Catalyzed by a four-times exchanged β zeolite (10 g/mol benzoyl chloride) which was calcined at 550°C, the benzoylation (100% conversion of benzoyl chloride and 87.7% selectivity for 2-benzoylnaphthalene) had been carried out at 220°C for 5 hr with 2 molar ratio of naphthalene to benzoyl chloride.